refactor(色彩管理): 统一色彩与四色保真

go.mod

@@ -10,7 +10,7 @@ require (
 	github.com/tdewolff/font v0.0.0-20261010204837-88a7f6b56918
 	github.com/xiaoqidun/j2kgo v1.0.1
 	github.com/xiaoqidun/jbig2 v1.1.7
-	github.com/xiaoqidun/pdfgo v0.0.0-20261015084227-8b2c590c8095
+	github.com/xiaoqidun/pdfgo v0.0.0-20261015160218-fa5114475eb5
 	golang.org/x/crypto v0.58.0
 	golang.org/x/image v0.47.0
 	golang.org/x/text v0.43.0

go.sum

@@ -62,8 +62,8 @@ github.com/xiaoqidun/j2kgo v1.0.1 h1:W0SytzjvgiOhXwq+JNRSVKLB847fjGOvGWTNKqmwvo0
 github.com/xiaoqidun/j2kgo v1.0.1/go.mod h1:DCwAfuDzCDYqUiAlZ7BDwigTjaXw7o9L1FtEma/D1aA=
 github.com/xiaoqidun/jbig2 v1.1.7 h1:118d2lQn2ZsupmXazK+2p23Jp5xQ09btBmPUoYoa/+Y=
 github.com/xiaoqidun/jbig2 v1.1.7/go.mod h1:9jromqVwMqlptUDEt6Yip8vqYA5I1YjhG7FgMl/Z2dA=
-github.com/xiaoqidun/pdfgo v0.0.0-20261015084227-8b2c590c8095 h1:lkK0xbGXJIKvH9zgKtf94HiGt35krCmy8EESPUCxRFE=
-github.com/xiaoqidun/pdfgo v0.0.0-20261015084227-8b2c590c8095/go.mod h1:FUQ8+TfNoec6tZCdsckx+rrD25JACm7EzuZyFH37QHg=
+github.com/xiaoqidun/pdfgo v0.0.0-20261015160218-fa5114475eb5 h1:eJuai2A2q9R8Mo/oKXiIpNc41uzolkKplPWXUmYiHcU=
+github.com/xiaoqidun/pdfgo v0.0.0-20261015160218-fa5114475eb5/go.mod h1:FUQ8+TfNoec6tZCdsckx+rrD25JACm7EzuZyFH37QHg=
 github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
 github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
 github.com/yuin/goldmark v1.8.5 h1:r6N5afV5qj/5S4UTch8agZHJ8UxNCMwX7WjkkJam2NA=

internal/base/image/color.go

@@ -0,0 +1,321 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package image
+
+import (
+	"bytes"
+	"compress/zlib"
+	"context"
+	"encoding/binary"
+	"fmt"
+	"hash/crc32"
+	"image"
+	"image/color"
+	"io"
+	"math"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// colorImage 保留源采样及独立的十六位显示像素
+type colorImage struct {
+	*image.NRGBA64
+	source image.Image
+}
+
+// pngColor 保存PNG校准空间及缺省sRGB传递函数
+type pngColor struct {
+	space      *pdfgo.ColorSpace
+	linearSRGB bool
+}
+
+// pngColorProfile 读取PNG颜色元数据，ICC优先于sRGB及独立校准参数
+// 入参: ctx 取消上下文, data 原始编码
+// 返回: []byte ICC编码, *pngColor 校准参数, error 格式或配置错误
+func pngColorProfile(ctx context.Context, data []byte) ([]byte, *pngColor, error) {
+	const profileLimit = 16 << 20
+	chunks := make(map[string][]byte)
+	for at := 8; at < len(data); {
+		if err := ctx.Err(); err != nil {
+			return nil, nil, err
+		}
+		if len(data)-at < 8 {
+			return nil, nil, fmt.Errorf("truncated PNG chunk")
+		}
+		kind := string(data[at+4 : at+8])
+		if kind == "IDAT" || kind == "PLTE" {
+			break
+		}
+		if len(data)-at < 12 {
+			return nil, nil, fmt.Errorf("truncated PNG chunk")
+		}
+		size := uint64(binary.BigEndian.Uint32(data[at:]))
+		if size > uint64(len(data)-at-12) {
+			return nil, nil, fmt.Errorf("invalid PNG chunk length")
+		}
+		end := at + 8 + int(size)
+		switch kind {
+		case "iCCP", "sRGB", "gAMA", "cHRM":
+			if _, ok := chunks[kind]; ok {
+				return nil, nil, fmt.Errorf("invalid PNG %s chunk order", kind)
+			}
+			if crc32.ChecksumIEEE(data[at+4:end]) != binary.BigEndian.Uint32(data[end:]) {
+				return nil, nil, fmt.Errorf("invalid PNG %s checksum", kind)
+			}
+			chunks[kind] = data[at+8 : end]
+		}
+		at = end + 4
+		if kind == "IEND" {
+			break
+		}
+	}
+	if chunk, ok := chunks["iCCP"]; ok {
+		name := bytes.IndexByte(chunk, 0)
+		if name < 1 || name > 79 || len(chunk) < name+3 || chunk[name+1] != 0 {
+			return nil, nil, fmt.Errorf("invalid PNG ICC header")
+		}
+		for i, c := range chunk[:name] {
+			if c < 32 || c > 126 && c < 161 || c == 32 && (i == 0 || i == name-1 || chunk[i-1] == 32) {
+				return nil, nil, fmt.Errorf("invalid PNG ICC name")
+			}
+		}
+		input := bytes.NewReader(chunk[name+2:])
+		reader, err := zlib.NewReader(input)
+		if err != nil {
+			return nil, nil, err
+		}
+		profile, err := io.ReadAll(io.LimitReader(contextInput{ReadCloser: reader, context: ctx}, profileLimit+1))
+		closeErr := reader.Close()
+		if err != nil {
+			return nil, nil, err
+		}
+		if closeErr != nil {
+			return nil, nil, closeErr
+		}
+		if len(profile) > profileLimit {
+			return nil, nil, fmt.Errorf("PNG ICC profile exceeds size limit")
+		}
+		if input.Len() != 0 {
+			return nil, nil, fmt.Errorf("trailing PNG ICC data")
+		}
+		kind := "RGB "
+		if len(data) > 25 && (data[25] == 0 || data[25] == 4) {
+			kind = "GRAY"
+		}
+		if len(profile) < 132 || string(profile[16:20]) != kind {
+			return nil, nil, fmt.Errorf("ICC source model does not match PNG color space %q", kind)
+		}
+		return profile, nil, nil
+	}
+	if chunk, ok := chunks["sRGB"]; ok {
+		if len(chunk) != 1 || chunk[0] > 3 {
+			return nil, nil, fmt.Errorf("invalid PNG sRGB intent")
+		}
+		return nil, nil, nil
+	}
+	if len(chunks) == 0 {
+		return nil, nil, nil
+	}
+	coordinates := [8]float64{0.3127, 0.3290, 0.6400, 0.3300, 0.3000, 0.6000, 0.1500, 0.0600}
+	if chunk, ok := chunks["cHRM"]; ok {
+		if len(chunk) != 32 {
+			return nil, nil, fmt.Errorf("invalid PNG chromaticities")
+		}
+		for i := range coordinates {
+			coordinates[i] = float64(binary.BigEndian.Uint32(chunk[i*4:])) / 100000
+		}
+	}
+	var xyz [4][3]float64
+	for i := range xyz {
+		x, y := coordinates[2*i], coordinates[2*i+1]
+		if y <= 0 || x < 0 || x+y > 1 {
+			return nil, nil, fmt.Errorf("invalid PNG chromaticities")
+		}
+		xyz[i] = [3]float64{x / y, 1, (1 - x - y) / y}
+	}
+	white := xyz[0]
+	det := func(a, b, c [3]float64) float64 {
+		return a[0]*(b[1]*c[2]-b[2]*c[1]) - b[0]*(a[1]*c[2]-a[2]*c[1]) + c[0]*(a[1]*b[2]-a[2]*b[1])
+	}
+	d := det(xyz[1], xyz[2], xyz[3])
+	if math.Abs(d) < 1e-12 {
+		return nil, nil, fmt.Errorf("degenerate PNG chromaticities")
+	}
+	scale := [3]float64{det(white, xyz[2], xyz[3]) / d, det(xyz[1], white, xyz[3]) / d, det(xyz[1], xyz[2], white) / d}
+	var matrix [9]float64
+	for i := range 3 {
+		for j := range 3 {
+			matrix[3*i+j] = xyz[i+1][j] * scale[i]
+		}
+	}
+	gamma := [3]float64{1, 1, 1}
+	linear := true
+	if chunk, ok := chunks["gAMA"]; ok {
+		if len(chunk) != 4 || binary.BigEndian.Uint32(chunk) == 0 {
+			return nil, nil, fmt.Errorf("invalid PNG gamma")
+		}
+		g := 100000 / float64(binary.BigEndian.Uint32(chunk))
+		gamma = [3]float64{g, g, g}
+		linear = false
+	}
+	space, err := pdfgo.NewCalRGBColorSpace(white, [3]float64{}, gamma, matrix)
+	if err != nil {
+		return nil, nil, err
+	}
+	return nil, &pngColor{space: space, linearSRGB: linear}, nil
+}
+
+// jpegColorProfile 读取JPEG分段ICC配置，拒绝缺段、重复及模型不匹配
+// 入参: ctx 取消上下文, data JPEG编码, model 源颜色模型
+// 返回: []byte 独立配置编码，未声明时为nil, error 配置或取消错误
+func jpegColorProfile(ctx context.Context, data []byte, model color.Model) ([]byte, error) {
+	var parts [255][]byte
+	count, found, total := 0, 0, 0
+	for at := 2; at < len(data); {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		if data[at] != 0xff {
+			return nil, fmt.Errorf("invalid JPEG marker")
+		}
+		for at < len(data) && data[at] == 0xff {
+			at++
+		}
+		if at == len(data) {
+			return nil, fmt.Errorf("truncated JPEG marker")
+		}
+		marker := data[at]
+		at++
+		if marker == 0xda || marker == 0xd9 {
+			break
+		}
+		if marker == 0x01 || marker >= 0xd0 && marker <= 0xd7 {
+			continue
+		}
+		if len(data)-at < 2 {
+			return nil, fmt.Errorf("truncated JPEG segment")
+		}
+		size := int(binary.BigEndian.Uint16(data[at:]))
+		if size < 2 || size > len(data)-at {
+			return nil, fmt.Errorf("invalid JPEG segment length")
+		}
+		segment := data[at+2 : at+size]
+		at += size
+		if marker != 0xe2 || !bytes.HasPrefix(segment, []byte("ICC_PROFILE\x00")) {
+			continue
+		}
+		if len(segment) <= 14 {
+			return nil, fmt.Errorf("truncated JPEG color profile")
+		}
+		index, n := int(segment[12]), int(segment[13])
+		if index == 0 || index > n || count != 0 && count != n || parts[index-1] != nil {
+			return nil, fmt.Errorf("invalid JPEG color profile sequence")
+		}
+		count, found = n, found+1
+		parts[index-1] = segment[14:]
+		total += len(segment) - 14
+	}
+	if found == 0 {
+		return nil, nil
+	}
+	if found != count {
+		return nil, fmt.Errorf("incomplete JPEG color profile")
+	}
+	profile := make([]byte, 0, total)
+	for _, part := range parts[:count] {
+		profile = append(profile, part...)
+	}
+	kind := "RGB "
+	if model == color.CMYKModel {
+		kind = "CMYK"
+	} else if model == color.GrayModel {
+		kind = "GRAY"
+	}
+	if len(profile) < 132 || string(profile[16:20]) != kind {
+		return nil, fmt.Errorf("ICC source model does not match JPEG color space %q", kind)
+	}
+	return profile, nil
+}
+
+// jpegDisplayImage 统一JPEG显示变换，保留源分量并使用文档内嵌ICC
+// 入参: ctx 取消上下文, source 源像素, profile 颜色配置，可为nil
+// 返回: image.Image 显示像素, error 变换或取消错误
+func jpegDisplayImage(ctx context.Context, source image.Image, profile *pdfgo.ColorSpace) (image.Image, error) {
+	cmyk, ok := source.(*image.CMYK)
+	if !ok {
+		if profile != nil {
+			return applyTIFFColorProfile(ctx, source, profile)
+		}
+		return source, nil
+	}
+	if profile == nil {
+		profile = &pdfgo.ColorSpace{Model: "DeviceCMYK"}
+	}
+	bounds := cmyk.Bounds()
+	if bounds.Dx() <= 0 || bounds.Dy() <= 0 || bounds.Dx() > math.MaxInt/8/bounds.Dy() {
+		return nil, fmt.Errorf("JPEG color image dimensions exceed capacity")
+	}
+	pixels := image.NewNRGBA64(bounds)
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			if (x-bounds.Min.X)&255 == 0 {
+				if err := ctx.Err(); err != nil {
+					return nil, err
+				}
+			}
+			ink := cmyk.CMYKAt(x, y)
+			values := [4]float64{float64(ink.C) / 255, float64(ink.M) / 255, float64(ink.Y) / 255, float64(ink.K) / 255}
+			rgb, err := profile.SRGB(values[:], profile.DefaultIntent())
+			if err != nil {
+				return nil, err
+			}
+			pixels.SetNRGBA64(x, y, color.NRGBA64{R: colorWord(rgb[0]), G: colorWord(rgb[1]), B: colorWord(rgb[2]), A: 65535})
+		}
+	}
+	return &colorImage{NRGBA64: pixels, source: source}, nil
+}
+
+// colorWord 将归一化颜色舍入为十六位分量
+// 入参: value 颜色分量
+// 返回: uint16 十六位分量
+func colorWord(value float64) uint16 {
+	return uint16(math.Round(max(0, min(1, value)) * 65535))
+}
+
+// cmykGrayAt 从原始四色采样计算蒙版灰度，不应用显示配置
+// 入参: x 横坐标, y 纵坐标
+// 返回: color.Gray 蒙版灰度
+func (p *planarTIFFImage) cmykGrayAt(x, y int) color.Gray {
+	if !image.Pt(x, y).In(p.bounds) {
+		return color.Gray{}
+	}
+	ink := p.inksAt(x, y)
+	maximum := uint32(65535)
+	if p.alpha == 1 {
+		maximum = uint32(ink[4])
+		if maximum == 0 {
+			return color.Gray{}
+		}
+	}
+	black := maximum - min(uint32(ink[3]), maximum)
+	var rgb [3]uint32
+	for i := range rgb {
+		rgb[i] = (maximum - min(uint32(ink[i]), maximum)) * black / maximum
+		if p.alpha != 1 {
+			rgb[i] = rgb[i] * uint32(ink[4]) / 65535
+		}
+	}
+	return color.Gray{Y: uint8((19595*rgb[0] + 38470*rgb[1] + 7471*rgb[2] + 1<<15) >> 24)}
+}

internal/base/image/encoded.go

@@ -26,17 +26,21 @@ import (
 	"io"
 	"sync"
 	"sync/atomic"
+
+	"github.com/xiaoqidun/pdfgo"
 )
 
 // EncodedImage 保留PNG或JPEG原始编码，首次读取像素时解码
 // Bytes返回只读数据，Image返回共享只读像素，解码错误由Image返回
 type EncodedImage struct {
-	data    []byte
-	format  string
-	config  image.Config
-	result  atomic.Pointer[encodedImageResult]
-	mu      sync.Mutex
-	pending chan struct{}
+	data     []byte
+	format   string
+	config   image.Config
+	profile  []byte
+	pngColor *pngColor
+	result   atomic.Pointer[encodedImageResult]
+	mu       sync.Mutex
+	pending  chan struct{}
 }
 
 // encodedImageResult 保存已完成的像素解码结果，不保存取消或超时错误
@@ -65,9 +69,14 @@ func (img *EncodedImage) Bytes() []byte { return img.data }
 // 返回: string 媒体类型
 func (img *EncodedImage) MIME() string { return "image/" + img.format }
 
-// ColorModel 返回头信息中的颜色模型，不解码像素
+// ColorModel 返回显示像素的颜色模型，不解码像素
 // 返回: color.Model 颜色模型
-func (img *EncodedImage) ColorModel() color.Model { return img.config.ColorModel }
+func (img *EncodedImage) ColorModel() color.Model {
+	if img.profile != nil || img.pngColor != nil || img.config.ColorModel == color.CMYKModel {
+		return color.NRGBA64Model
+	}
+	return img.config.ColorModel
+}
 
 // Bounds 返回图片范围，不解码像素
 // 返回: image.Rectangle 图片范围
@@ -131,6 +140,18 @@ func (img *EncodedImage) decodeContext(ctx context.Context, pending chan struct{
 		img.mu.Unlock()
 	}()
 	pixels, _, err := image.Decode(contextInput{ReadCloser: io.NopCloser(bytes.NewReader(img.data)), context: ctx})
+	if err == nil && (img.format == "jpeg" || img.profile != nil) {
+		var profile *pdfgo.ColorSpace
+		if img.profile != nil {
+			profile, err = pdfgo.NewICCColorSpace(img.profile)
+		}
+		if err == nil {
+			pixels, err = jpegDisplayImage(ctx, pixels, profile)
+		}
+	}
+	if err == nil && img.pngColor != nil {
+		pixels, err = applyImageColorProfile(ctx, pixels, img.pngColor.space, img.pngColor.linearSRGB)
+	}
 	if cancelErr := ctx.Err(); cancelErr != nil {
 		return nil, cancelErr
 	}
@@ -173,5 +194,18 @@ func newEncodedImageContext(ctx context.Context, data []byte) (*EncodedImage, er
 	if format != "jpeg" && format != "png" {
 		return nil, fmt.Errorf("unsupported encoded image %q", format)
 	}
-	return &EncodedImage{data: data, format: format, config: config}, nil
+	img := &EncodedImage{data: data, format: format, config: config}
+	if format == "jpeg" {
+		img.profile, err = jpegColorProfile(ctx, data, config.ColorModel)
+		if err != nil {
+			return nil, err
+		}
+	}
+	if format == "png" {
+		img.profile, img.pngColor, err = pngColorProfile(ctx, data)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return img, nil
 }

internal/base/image/image.go

@@ -441,6 +441,46 @@ func PixelDataContext(ctx context.Context, img image.Image) (image.Image, error)
 // 入参: img 图片对象, x X坐标, y Y坐标
 // 返回: color.Gray 灰度像素
 func GrayAt(img image.Image, x, y int) color.Gray {
+	switch src := img.(type) {
+	case *EncodedImage:
+		pixels, err := src.Image()
+		if err != nil {
+			return color.Gray{}
+		}
+		return GrayAt(pixels, x, y)
+	case *colorImage:
+		return GrayAt(src.source, x, y)
+	case *maskedTIFFImage:
+		if src.NRGBA64At(x, y).A == 0 {
+			return color.Gray{}
+		}
+		bounds, size := src.source.Bounds(), src.bounds.Size()
+		sx := bounds.Min.X + int((uint64(x-src.bounds.Min.X)*uint64(bounds.Dx())+uint64(bounds.Dx()/2))/uint64(size.X))
+		sy := bounds.Min.Y + int((uint64(y-src.bounds.Min.Y)*uint64(bounds.Dy())+uint64(bounds.Dy()/2))/uint64(size.Y))
+		return GrayAt(src.source, sx, sy)
+	case *transparentEdgeImage:
+		if x <= src.rect.Min.X || y <= src.rect.Min.Y || x >= src.rect.Max.X-1 || y >= src.rect.Max.Y-1 {
+			return color.Gray{}
+		}
+		bounds := src.source.Bounds()
+		return GrayAt(src.source, bounds.Min.X+x-1, bounds.Min.Y+y-1)
+	case *transparentEdgeImage64:
+		if x <= src.rect.Min.X || y <= src.rect.Min.Y || x >= src.rect.Max.X-1 || y >= src.rect.Max.Y-1 {
+			return color.Gray{}
+		}
+		bounds := src.source.Bounds()
+		return GrayAt(src.source, bounds.Min.X+x-1, bounds.Min.Y+y-1)
+	case *orientedTIFFImage:
+		point, ok := src.sourcePoint(x, y)
+		if !ok {
+			return color.Gray{}
+		}
+		return GrayAt(src.source, point.X, point.Y)
+	case *planarTIFFImage:
+		if src.cmyk {
+			return src.cmykGrayAt(x, y)
+		}
+	}
 	if src, ok := img.(*image.Gray); ok {
 		return src.GrayAt(x, y)
 	}
@@ -662,12 +702,19 @@ func WithTransparentEdge(ctx context.Context, img image.Image) (image.Image, int
 		return img, 0, nil
 	}
 	if src, ok := img.(*EncodedImage); ok && src.MIME() == "image/jpeg" {
+		if src.profile != nil || src.config.ColorModel == color.CMYKModel {
+			pixels, err := src.ImageContext(ctx)
+			return pixels, 0, err
+		}
 		return img, 0, nil
 	}
 	source, err := PixelDataContext(ctx, img)
 	if err != nil {
 		return nil, 0, err
 	}
+	if encoded, ok := img.(*EncodedImage); ok && (encoded.profile != nil || encoded.pngColor != nil) {
+		img = source
+	}
 	switch source.(type) {
 	case *image.Gray, *image.Gray16, *image.YCbCr, *image.CMYK:
 		return img, 0, nil

internal/base/image/storage.go

@@ -14,7 +14,10 @@
 
 package image
 
-import "image"
+import (
+	"image"
+	"image/color"
+)
 
 // StorageCost 预留十六位像素空间，并计入编码、调色板与底层像素缓冲容量
 // 包装图像可实现BackingImage() image.Image，使底层共享缓冲计入预算
@@ -28,6 +31,25 @@ func StorageCost(img image.Image, limit int) int {
 	}
 	pixels := w * h * 8
 	if encoded, ok := img.(*EncodedImage); ok {
+		if encoded.pngColor != nil {
+			if limit-cost < 512 {
+				return limit + 1
+			}
+			cost += 512
+		}
+		if cap(encoded.profile) > limit-cost {
+			return limit + 1
+		}
+		cost += cap(encoded.profile)
+		if encoded.profile != nil || encoded.pngColor != nil || encoded.config.ColorModel == color.CMYKModel {
+			if w > (limit-cost)/12/h {
+				return limit + 1
+			}
+			pixels = w * h * 12
+		}
+		if result := encoded.result.Load(); result != nil && result.image != nil {
+			pixels = max(pixels, StorageCost(result.image, limit-cost))
+		}
 		if cap(encoded.data) > limit-cost-pixels {
 			return limit + 1
 		}
@@ -35,6 +57,9 @@ func StorageCost(img image.Image, limit int) int {
 	}
 	var buffers [5]int
 	switch source := img.(type) {
+	case *colorImage:
+		buffers[0] = cap(source.Pix)
+		buffers[1] = StorageCost(source.source, limit-cost)
 	case *image.RGBA:
 		buffers[0] = cap(source.Pix)
 	case *image.RGBA64:

internal/base/image/tiff_planar.go

@@ -23,6 +23,8 @@ import (
 	"image/color"
 	"io"
 	"math"
+
+	"github.com/xiaoqidun/pdfgo"
 )
 
 // tiffPlaneInput 将单分量目录附加到只读视图，像素仍从原始编码读取
@@ -60,14 +62,18 @@ func (layout TIFFLayout) needsSampleView() bool {
 // 返回: uint64 每像素预算字节数
 func (layout TIFFLayout) DecodedPixelBytes() uint64 {
 	samples := uint64(layout.Samples)
+	profile := uint64(0)
+	if layout.profileSize != 0 {
+		profile = 8
+	}
 	if layout.Planar {
 		if layout.photometric == 5 && samples > 4 {
-			return 20
+			return 20 + profile
 		}
-		return 16
+		return 16 + profile
 	}
 	if !layout.needsSampleView() {
-		return 8
+		return 8 + profile
 	}
 	bytes := uint64(1)
 	if layout.depth == 2 || layout.depth == 4 {
@@ -75,7 +81,7 @@ func (layout TIFFLayout) DecodedPixelBytes() uint64 {
 	} else if layout.depth > 8 {
 		bytes = 2
 	}
-	return max(uint64(8), samples*bytes)
+	return max(uint64(8), samples*bytes) + profile
 }
 
 // decodeTIFFPixels 按存储方式解码指定目录并统一颜色和显示方向
@@ -647,12 +653,12 @@ func (p *planarTIFFImage) ColorModel() color.Model {
 		return color.GrayModel
 	}
 	if p.alpha == 1 {
-		if p.depth > 8 {
+		if p.depth > 8 || p.cmyk {
 			return color.RGBA64Model
 		}
 		return color.RGBAModel
 	}
-	if p.depth > 8 {
+	if p.depth > 8 || p.cmyk {
 		return color.NRGBA64Model
 	}
 	return color.NRGBAModel
@@ -674,10 +680,14 @@ func (p *planarTIFFImage) components(x, y int) [4]uint16 {
 				return [4]uint16{}
 			}
 		}
-		black := maximum - min(uint32(ink[3]), maximum)
+		var components [4]float64
+		for i := range components {
+			components[i] = float64(min(uint32(ink[i]), maximum)) / float64(maximum)
+		}
+		rgb, _ := (&pdfgo.ColorSpace{Model: "DeviceCMYK"}).SRGB(components[:], "")
 		var values [4]uint16
 		for i := range 3 {
-			values[i] = uint16((maximum - min(uint32(ink[i]), maximum)) * black / maximum)
+			values[i] = uint16(math.Round(rgb[i] * float64(maximum)))
 		}
 		values[3] = ink[4]
 		return values

internal/base/image/tiff_profile.go

@@ -31,7 +31,7 @@ import (
 func parseTIFFColorProfile(kind string, data []byte) (*pdfgo.ColorSpace, error) {
 	model := map[string]string{"GRAY": "GRAY", "RGB": "RGB ", "CMYK": "CMYK"}[strings.ToUpper(kind)]
 	if len(data) < 132 || model == "" || string(data[16:20]) != model {
-		return nil, fmt.Errorf("ICC source model does not match OFD color space %q", kind)
+		return nil, fmt.Errorf("ICC source model does not match image color space %q", kind)
 	}
 	return pdfgo.NewICCColorSpace(data)
 }
@@ -75,6 +75,13 @@ func readTIFFColorProfile(ctx context.Context, data []byte, layout TIFFLayout) (
 // 入参: ctx 取消上下文，可为nil, source 解码图像, profile 已校验的颜色配置
 // 返回: image.Image 独立透明度图像, error 颜色变换或取消错误
 func applyTIFFColorProfile(ctx context.Context, source image.Image, profile *pdfgo.ColorSpace) (image.Image, error) {
+	return applyImageColorProfile(ctx, source, profile, false)
+}
+
+// applyImageColorProfile 按源配置转换显示像素，缺省传递函数在浮点域解码
+// 入参: ctx 取消上下文, source 源像素, profile 颜色空间, linearSRGB 是否先解码sRGB传递函数
+// 返回: image.Image 十六位显示图像, error 变换或取消错误
+func applyImageColorProfile(ctx context.Context, source image.Image, profile *pdfgo.ColorSpace, linearSRGB bool) (image.Image, error) {
 	if ctx == nil {
 		ctx = context.Background()
 	}
@@ -144,7 +151,16 @@ func applyTIFFColorProfile(ctx context.Context, source image.Image, profile *pdf
 				alpha = pixel.A
 				values = [4]float64{float64(pixel.R) / 65535, float64(pixel.G) / 65535, float64(pixel.B) / 65535}
 			}
-			rgb, err := profile.RGB(values[:profile.Components()], profile.DefaultIntent())
+			if linearSRGB {
+				for i := range 3 {
+					if values[i] <= 0.04045 {
+						values[i] /= 12.92
+					} else {
+						values[i] = math.Pow((values[i]+0.055)/1.055, 2.4)
+					}
+				}
+			}
+			rgb, err := profile.SRGB(values[:profile.Components()], profile.DefaultIntent())
 			if err != nil {
 				return nil, err
 			}
@@ -161,7 +177,7 @@ func applyTIFFColorProfile(ctx context.Context, source image.Image, profile *pdf
 	if err := ctx.Err(); err != nil {
 		return nil, err
 	}
-	return result, nil
+	return &colorImage{NRGBA64: result, source: source}, nil
 }
 
 // newTIFFProfileTable 为离散颜色分配查找表，预乘颜色及小图保持逐像素变换

internal/codec/pdf/color.go

@@ -76,11 +76,7 @@ func (c *TransferCache) Resolve(reader *pdfgo.Reader, style pdfgo.Style, model p
 // 入参: space 合成空间, values 非预乘分量
 // 返回: [3]float64 显示颜色, error 校准颜色转换错误
 func OutputColor(space *pdfgo.ColorSpace, values [4]float64) ([3]float64, error) {
-	if space.Model == "DeviceCMYK" && !space.Calibrated() {
-		black := 1 - values[3]
-		return [3]float64{(1 - values[0]) * black, (1 - values[1]) * black, (1 - values[2]) * black}, nil
-	}
-	return space.RGB(values[:space.Components()], "RelativeColorimetric")
+	return space.SRGB(values[:space.Components()], "RelativeColorimetric")
 }
 
 // NormalBlend 判断混合模式是否为普通覆盖

internal/codec/pdf/image.go

@@ -15,6 +15,11 @@
 package pdf
 
 import (
+	"bytes"
+	"compress/zlib"
+	"context"
+	"encoding/binary"
+	"fmt"
 	"image"
 	"image/color"
 	"math"
@@ -23,6 +28,121 @@ import (
 	"github.com/xiaoqidun/pdfgo"
 )
 
+// EncodeCMYKTIFF 将直接四色图像保存为十六位无损TIFF，不经过显示颜色转换
+// 入参: ctx 取消上下文, source PDF源图像
+// 返回: []byte 含ICC和非预乘透明度的TIFF，非四色图像为nil, error 解码或编码错误
+func EncodeCMYKTIFF(ctx context.Context, source *pdfgo.Image) ([]byte, error) {
+	if ctx == nil || source == nil {
+		return nil, fmt.Errorf("missing CMYK image context or source")
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if source.ImageMask {
+		return nil, nil
+	}
+	family, err := source.ColorSpaceFamily()
+	if err != nil || family != "DeviceCMYK" && family != "ICCBased" {
+		return nil, err
+	}
+	if family == "ICCBased" {
+		count, err := source.ColorSpaceComponents()
+		if err != nil || count != 4 {
+			return nil, err
+		}
+	}
+	components, err := source.DecodeComponentsViewContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if components.Space == nil || components.Space.Model != "DeviceCMYK" || components.Space.Components() != 4 || components.ColorantSpace != nil {
+		return nil, nil
+	}
+	bounds := components.Rect
+	width, height := bounds.Dx(), bounds.Dy()
+	if width <= 0 || height <= 0 || width > int(^uint(0)>>1)/10 || uint64(width) > uint64(^uint32(0))/10 || uint64(height) > uint64(^uint32(0)) {
+		return nil, fmt.Errorf("invalid CMYK TIFF dimensions")
+	}
+	profile := components.Space.ICCProfile(source.Intent)
+	count := 12
+	if len(profile) != 0 {
+		count++
+	}
+	bitsOffset := uint64(8 + 2 + count*12 + 4)
+	profileOffset := bitsOffset + 10
+	stripOffset := (profileOffset + uint64(len(profile)) + 1) &^ uint64(1)
+	if stripOffset > uint64(^uint32(0)) {
+		return nil, fmt.Errorf("CMYK TIFF profile exceeds size limit")
+	}
+	var compressed bytes.Buffer
+	writer := zlib.NewWriter(&compressed)
+	row := make([]byte, width*10)
+	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
+		for x := bounds.Min.X; x < bounds.Max.X; x++ {
+			if (x-bounds.Min.X)%1024 == 0 {
+				if err := ctx.Err(); err != nil {
+					writer.Close()
+					return nil, err
+				}
+			}
+			values, alpha := components.ValuesAt(x, y)
+			pixel := row[(x-bounds.Min.X)*10:]
+			for channel, value := range [5]float64{values[0], values[1], values[2], values[3], alpha} {
+				if math.IsNaN(value) || math.IsInf(value, 0) || value < 0 || value > 1 {
+					writer.Close()
+					return nil, fmt.Errorf("invalid CMYK TIFF component")
+				}
+				binary.LittleEndian.PutUint16(pixel[channel*2:], uint16(math.Round(value*65535)))
+			}
+		}
+		if _, err := writer.Write(row); err != nil {
+			writer.Close()
+			return nil, err
+		}
+		if stripOffset+uint64(compressed.Len()) > uint64(^uint32(0)) {
+			writer.Close()
+			return nil, fmt.Errorf("CMYK TIFF exceeds size limit")
+		}
+	}
+	if err := writer.Close(); err != nil {
+		return nil, err
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	total := stripOffset + uint64(compressed.Len())
+	if total > uint64(^uint32(0)) || total > uint64(int(^uint(0)>>1)) {
+		return nil, fmt.Errorf("CMYK TIFF exceeds size limit")
+	}
+	data := make([]byte, int(total))
+	copy(data, "II")
+	binary.LittleEndian.PutUint16(data[2:], 42)
+	binary.LittleEndian.PutUint32(data[4:], 8)
+	binary.LittleEndian.PutUint16(data[8:], uint16(count))
+	entries := [][4]uint32{
+		{256, 4, 1, uint32(width)}, {257, 4, 1, uint32(height)},
+		{258, 3, 5, uint32(bitsOffset)}, {259, 3, 1, 8}, {262, 3, 1, 5},
+		{273, 4, 1, uint32(stripOffset)}, {277, 3, 1, 5}, {278, 4, 1, uint32(height)},
+		{279, 4, 1, uint32(compressed.Len())}, {284, 3, 1, 1}, {332, 3, 1, 1}, {338, 3, 1, 2},
+	}
+	if len(profile) != 0 {
+		entries = append(entries, [4]uint32{34675, 7, uint32(len(profile)), uint32(profileOffset)})
+	}
+	for i, entry := range entries {
+		p := data[10+i*12:]
+		binary.LittleEndian.PutUint16(p, uint16(entry[0]))
+		binary.LittleEndian.PutUint16(p[2:], uint16(entry[1]))
+		binary.LittleEndian.PutUint32(p[4:], entry[2])
+		binary.LittleEndian.PutUint32(p[8:], entry[3])
+	}
+	for i := range 5 {
+		binary.LittleEndian.PutUint16(data[int(bitsOffset)+2*i:], 16)
+	}
+	copy(data[int(profileOffset):], profile)
+	copy(data[int(stripOffset):], compressed.Bytes())
+	return data, nil
+}
+
 // StencilImage 按当前填充色读取模板图像，不分配整幅彩色样本
 type StencilImage struct {
 	Source image.Image

ofdgo_color_profile.go

@@ -97,11 +97,33 @@ func (r *Renderer) colorDefinition(id string) *ColorSpace {
 	return space
 }
 
-// rgb 转换归一化源分量，不在ICC变换前量化为8位
+// srgb 转换归一化源分量，不在ICC变换前量化为8位
 // 入参: values 源分量
 // 返回: [3]float64 sRGB分量, error 变换错误
-func (p *colorProfile) rgb(values [4]float64) ([3]float64, error) {
-	return p.space.RGB(values[:p.space.Components()], p.space.DefaultIntent())
+func (p *colorProfile) srgb(values [4]float64) ([3]float64, error) {
+	return p.space.SRGB(values[:p.space.Components()], p.space.DefaultIntent())
+}
+
+// displayColor 按源模型及配置转换显示颜色，保持源分量精度
+// 入参: kind 源模型, values 归一化分量, profile 可选ICC配置
+// 返回: [3]float64 sRGB分量, error 模型或转换错误
+func displayColor(kind string, values [4]float64, profile *colorProfile) ([3]float64, error) {
+	if profile != nil {
+		return profile.srgb(values)
+	}
+	var model pdfgo.Name
+	switch kind {
+	case "GRAY":
+		model = "DeviceGray"
+	case "RGB":
+		model = "DeviceRGB"
+	case "CMYK":
+		model = "DeviceCMYK"
+	default:
+		return [3]float64{}, fmt.Errorf("unsupported color space %q", kind)
+	}
+	space := pdfgo.ColorSpace{Model: model}
+	return space.SRGB(values[:space.Components()], "RelativeColorimetric")
 }
 
 // profileColor 将显示分量一次量化并按透明度预乘

ofdgo_editor_color.go

@@ -278,7 +278,6 @@ func (e *Editor) Color(value *FillColor) (color.NRGBA, error) {
 	if len(fields) != 0 && len(fields) != count {
 		return color.NRGBA{}, fmt.Errorf("expected %d color components", count)
 	}
-	var components [4]uint8
 	var normalized [4]float64
 	limit := 1<<bits - 1
 	for i, field := range fields {
@@ -286,15 +285,8 @@ func (e *Editor) Color(value *FillColor) (color.NRGBA, error) {
 		if err != nil || v < 0 || v > limit {
 			return color.NRGBA{}, fmt.Errorf("invalid color component %q", field)
 		}
-		components[i] = uint8((v*255 + limit/2) / limit)
 		normalized[i] = float64(v) / float64(limit)
 	}
-	r, g, b := components[0], components[1], components[2]
-	if kind == "GRAY" {
-		g, b = r, r
-	} else if kind == "CMYK" {
-		r, g, b = color.CMYKToRGB(components[0], components[1], components[2], components[3])
-	}
 	var reader *Reader
 	if e.source != nil {
 		reader = e.source.reader
@@ -303,12 +295,9 @@ func (e *Editor) Color(value *FillColor) (color.NRGBA, error) {
 	if err != nil {
 		return color.NRGBA{}, err
 	}
-	if profile != nil {
-		rgb, err := profile.rgb(normalized)
-		if err != nil {
-			return color.NRGBA{}, err
-		}
-		r, g, b = meshByte(rgb[0]), meshByte(rgb[1]), meshByte(rgb[2])
+	rgb, err := displayColor(kind, normalized, profile)
+	if err != nil {
+		return color.NRGBA{}, err
 	}
 	a := 255
 	if value.Alpha != nil {
@@ -317,7 +306,7 @@ func (e *Editor) Color(value *FillColor) (color.NRGBA, error) {
 			return color.NRGBA{}, fmt.Errorf("color alpha must be between 0 and 255")
 		}
 	}
-	return color.NRGBA{R: r, G: g, B: b, A: uint8(a)}, nil
+	return color.NRGBA{R: meshByte(rgb[0]), G: meshByte(rgb[1]), B: meshByte(rgb[2]), A: uint8(a)}, nil
 }
 
 // RGBColor 创建浏览器等调用方使用的RGB纯色，非RGB文档按需注册独立颜色空间

ofdgo_paint.go

@@ -15,8 +15,10 @@
 package ofdgo
 
 import (
+	"fmt"
 	"image/color"
 	"math"
+	"slices"
 	"strconv"
 	"strings"
 )
@@ -30,100 +32,109 @@ type PatternPaint struct {
 
 // ResolveColor 按文档颜色空间和调色板解析颜色，返回预乘透明度的RGBA
 // 入参: value 颜色分量, index 调色板索引, space 颜色空间标识, alpha 透明度
-// 返回: color.RGBA 标准颜色
-func (r *Renderer) ResolveColor(value string, index *int, space string, alpha *int) color.RGBA {
-	return colorToRGBA(r.parseColorWithAlpha(value, index, space, alpha))
+// 返回: color.RGBA 标准颜色, error 颜色定义或配置错误
+func (r *Renderer) ResolveColor(value string, index *int, space string, alpha *int) (color.RGBA, error) {
+	kind, values, err := r.colorComponents(value, index, space)
+	if err != nil {
+		return color.RGBA{}, err
+	}
+	if alpha != nil && (*alpha < 0 || *alpha > 255) {
+		return color.RGBA{}, fmt.Errorf("color alpha must be between 0 and 255")
+	}
+	profile, err := r.Reader.colorProfile(r.colorDefinition(space))
+	if err != nil {
+		return color.RGBA{}, err
+	}
+	rgb, err := displayColor(kind, values, profile)
+	if err != nil {
+		return color.RGBA{}, err
+	}
+	a := 1.0
+	if alpha != nil {
+		a = float64(*alpha) / 255
+	}
+	return profileColor(rgb, a), nil
 }
 
 // GradientStops 解析OFD渐变分段的位置与透明度，返回独立数据并保留原分段顺序
 // 入参: segments 渐变分段, alpha 透明度
-// 返回: []ColorStop 后端无关的渐变色标
-func (r *Renderer) GradientStops(segments []ShdSegment, alpha *int) []ColorStop {
+// 返回: []ColorStop 后端无关的渐变色标, error 颜色定义或配置错误
+func (r *Renderer) GradientStops(segments []ShdSegment, alpha *int) ([]ColorStop, error) {
 	var gradient []ColorStop
 	positions := gradientPositions(segments)
 	for i, segment := range segments {
 		segmentAlpha := mergeAlpha(segment.Color.Alpha, alpha)
-		gradient = append(gradient, ColorStop{Offset: positions[i], Color: r.ResolveColor(segment.Color.Value, segment.Color.Index, segment.Color.ColorSpace, segmentAlpha)})
+		value, err := r.ResolveColor(segment.Color.Value, segment.Color.Index, segment.Color.ColorSpace, segmentAlpha)
+		if err != nil {
+			return nil, err
+		}
+		gradient = append(gradient, ColorStop{Offset: positions[i], Color: value})
 	}
-	return gradient
+	return gradient, nil
 }
 
 // parseColorWithAlpha 解析带透明度的颜色
 // 入参: value 色值, index 调色板索引, space 颜色空间标识, alpha 透明度
 // 返回: color.Color 颜色对象
 func (r *Renderer) parseColorWithAlpha(value string, index *int, space string, alpha *int) color.Color {
-	kind, values := r.colorComponents(value, index, space)
-	profile, err := r.Reader.colorProfile(r.colorDefinition(space))
+	result, err := r.ResolveColor(value, index, space, alpha)
 	if err != nil {
 		r.renderError = err
-		return color.RGBA{}
 	}
-	if profile != nil {
-		rgb, err := profile.rgb(values)
-		if err != nil {
-			r.renderError = err
-			return color.RGBA{}
-		}
-		a := 1.0
-		if alpha != nil {
-			a = float64(clampColor(*alpha)) / 255
-		}
-		return profileColor(rgb, a)
-	}
-	var components [4]uint8
-	for i, value := range values {
-		components[i] = uint8(math.Round(value * 255))
-	}
-	red, green, blue := components[0], components[1], components[2]
-	switch kind {
-	case "GRAY":
-		green, blue = red, red
-	case "CMYK":
-		red, green, blue = color.CMYKToRGB(components[0], components[1], components[2], components[3])
-	}
-	a := 255
-	if alpha != nil {
-		a = clampColor(*alpha)
-	}
-	return color.RGBA{R: uint8(int(red) * a / 255), G: uint8(int(green) * a / 255), B: uint8(int(blue) * a / 255), A: uint8(a)}
+	return result
 }
 
 // colorComponents 读取颜色空间及归一化分量，保留源位深供渐变插值
 // 入参: value 色值, index 调色板索引, space 颜色空间标识
-// 返回: string 颜色模型, [4]float64 单位分量
-func (r *Renderer) colorComponents(value string, index *int, space string) (string, [4]float64) {
+// 返回: string 颜色模型, [4]float64 单位分量, error 颜色定义错误
+func (r *Renderer) colorComponents(value string, index *int, space string) (string, [4]float64, error) {
 	cs := r.colorDefinition(space)
+	if cs == nil && (space != "" || r.Reader != nil && r.Reader.doc != nil && r.Reader.doc.CommonData.DefaultCS != 0) {
+		if space == "" {
+			space = strconv.Itoa(r.Reader.doc.CommonData.DefaultCS)
+		}
+		return "", [4]float64{}, fmt.Errorf("color space %q not found", space)
+	}
 	kind, bits, count := "RGB", 8, 3
 	if cs != nil {
 		kind = strings.ToUpper(cs.Type)
 		switch cs.BitsPerComponent {
+		case 0:
 		case 1, 2, 4, 8, 16:
 			bits = cs.BitsPerComponent
-		}
-		if strings.TrimSpace(value) == "" && index != nil && 0 <= *index && *index < len(cs.Palette) {
-			value = cs.Palette[*index]
+		default:
+			return "", [4]float64{}, fmt.Errorf("unsupported color depth %d", cs.BitsPerComponent)
 		}
 	}
+	if strings.TrimSpace(value) == "" && index != nil {
+		if cs == nil || *index < 0 || *index >= len(cs.Palette) {
+			return "", [4]float64{}, fmt.Errorf("color palette index out of range")
+		}
+		value = cs.Palette[*index]
+	}
 	switch kind {
+	case "RGB":
 	case "GRAY":
 		count = 1
 	case "CMYK":
 		count = 4
+	default:
+		return "", [4]float64{}, fmt.Errorf("unsupported color space %q", kind)
 	}
 	parts := strings.Fields(value)
 	var components [4]float64
 	limit := 1<<bits - 1
-	if len(parts) >= count {
-		for i, part := range parts[:count] {
-			v, err := parseColorComponent(part)
-			if err != nil || v < 0 || limit < v {
-				components = [4]float64{}
-				break
-			}
-			components[i] = float64(v) / float64(limit)
-		}
+	if len(parts) != 0 && len(parts) != count {
+		return "", components, fmt.Errorf("expected %d color components", count)
 	}
-	return kind, components
+	for i, part := range parts {
+		v, err := parseColorComponent(part)
+		if err != nil || v < 0 || limit < v {
+			return "", [4]float64{}, fmt.Errorf("invalid color component %q", part)
+		}
+		components[i] = float64(v) / float64(limit)
+	}
+	return kind, components, nil
 }
 
 // parseColorComponent 解析颜色分量
@@ -157,6 +168,12 @@ func mergeAlpha(colorAlpha, objectAlpha *int) *int {
 	if colorAlpha == nil && objectAlpha == nil {
 		return nil
 	}
+	for _, value := range []*int{colorAlpha, objectAlpha} {
+		if value != nil && (*value < 0 || *value > 255) {
+			alpha := *value
+			return &alpha
+		}
+	}
 	alpha := 255
 	if colorAlpha != nil {
 		alpha = *colorAlpha
@@ -164,7 +181,6 @@ func mergeAlpha(colorAlpha, objectAlpha *int) *int {
 	if objectAlpha != nil {
 		alpha = alpha * *objectAlpha / 255
 	}
-	alpha = clampColor(alpha)
 	return &alpha
 }
 
@@ -259,11 +275,15 @@ func (r *Renderer) parseShdColor(segments []ShdSegment, alpha *int) color.Color
 	return r.parseColorWithAlpha(c.Value, c.Index, c.ColorSpace, mergeAlpha(c.Alpha, alpha))
 }
 
-// renderGradientStops 在CMYK分量空间插值，将RGB分段误差控制在半个8位灰阶内
+// renderGradientStops 在源CMYK空间插值，保留截断边界及透明度变化
 // 入参: segments 原始颜色分段, alpha 对象透明度
 // 返回: []ColorStop 仅供绘制的颜色节点，不改变原始分段
 func (r *Renderer) renderGradientStops(segments []ShdSegment, alpha *int) []ColorStop {
-	stops := r.GradientStops(segments, alpha)
+	stops, err := r.GradientStops(segments, alpha)
+	if err != nil {
+		r.renderError = err
+		return nil
+	}
 	if len(stops) < 2 {
 		return stops
 	}
@@ -271,31 +291,14 @@ func (r *Renderer) renderGradientStops(segments []ShdSegment, alpha *int) []Colo
 	for i, stop := range stops {
 		if i > 0 && stops[i-1].Offset < stop.Offset {
 			a, b := segments[i-1].Color, segments[i].Color
-			leftKind, left := r.colorComponents(a.Value, a.Index, a.ColorSpace)
-			rightKind, right := r.colorComponents(b.Value, b.Index, b.ColorSpace)
-			if leftKind == "CMYK" && rightKind == "CMYK" {
-				a0, a1 := float64(stops[i-1].Color.A)/255, float64(stop.Color.A)/255
-				dk, da := right[3]-left[3], a1-a0
-				bound := 0.0
-				for c := 0; c < 3; c++ {
-					dc := right[c] - left[c]
-					bound = math.Max(bound, 2*math.Abs(dc*dk)+2*math.Abs(da)*(math.Abs(dc)+math.Abs(dk)))
-				}
-				steps := int(math.Ceil(math.Sqrt(bound * 255 / 4)))
-				if steps > 1 && result == nil {
-					result = append(make([]ColorStop, 0, len(stops)+steps-1), stops[:i]...)
-				}
-				for j := 1; j < steps; j++ {
-					t := float64(j) / float64(steps)
-					var values [4]float64
-					for c := range values {
-						values[c] = left[c]*(1-t) + right[c]*t
-					}
-					opacity := a0*(1-t) + a1*t
-					black := (1 - values[3]) * opacity * 255
-					color := color.RGBA{R: uint8(math.Round((1 - values[0]) * black)), G: uint8(math.Round((1 - values[1]) * black)), B: uint8(math.Round((1 - values[2]) * black)), A: uint8(math.Round(opacity * 255))}
-					result = append(result, ColorStop{Offset: stops[i-1].Offset*(1-t) + stop.Offset*t, Color: color})
+			leftKind, left, _ := r.colorComponents(a.Value, a.Index, a.ColorSpace)
+			rightKind, right, _ := r.colorComponents(b.Value, b.Index, b.ColorSpace)
+			leftSpace, rightSpace := r.colorDefinition(a.ColorSpace), r.colorDefinition(b.ColorSpace)
+			if leftKind == "CMYK" && rightKind == "CMYK" && (leftSpace == nil || leftSpace.Profile == "") && (rightSpace == nil || rightSpace.Profile == "") {
+				if result == nil {
+					result = append([]ColorStop(nil), stops[:i]...)
 				}
+				result = append(result, cmykGradientStops(left, right, stops[i-1], stop)...)
 			}
 		}
 		if result != nil {
@@ -308,6 +311,49 @@ func (r *Renderer) renderGradientStops(segments []ShdSegment, alpha *int) []Colo
 	return result
 }
 
+// cmykGradientStops 在加黑截断点分段，将预乘插值误差控制在四分之一灰阶内
+// 入参: left 左端分量, right 右端分量, start 左端色标, end 右端色标
+// 返回: []ColorStop 不含端点的显示色标
+func cmykGradientStops(left, right [4]float64, start, end ColorStop) []ColorStop {
+	positions := []float64{0, 1}
+	a0, a1 := float64(start.Color.A)/255, float64(end.Color.A)/255
+	bound := 0.0
+	for channel := 0; channel < 3; channel++ {
+		first, last := left[channel]+left[3], right[channel]+right[3]
+		delta := last - first
+		bound = math.Max(bound, 2*math.Abs((a1-a0)*delta))
+		if delta != 0 {
+			position := (1 - first) / delta
+			if 0 < position && position < 1 {
+				positions = append(positions, position)
+			}
+		}
+	}
+	slices.Sort(positions)
+	positions = slices.Compact(positions)
+	var result []ColorStop
+	for i := 1; i < len(positions); i++ {
+		first, last := positions[i-1], positions[i]
+		steps := max(1, int(math.Ceil((last-first)*math.Sqrt(bound*255/2))))
+		for step := 1; step <= steps; step++ {
+			t := first + (last-first)*float64(step)/float64(steps)
+			if t >= 1 {
+				continue
+			}
+			var values [4]float64
+			for channel := range values {
+				values[channel] = left[channel]*(1-t) + right[channel]*t
+			}
+			r, g, b := meshRGB("CMYK", values)
+			result = append(result, ColorStop{
+				Offset: start.Offset*(1-t) + end.Offset*t,
+				Color:  profileColor([3]float64{r, g, b}, a0*(1-t)+a1*t),
+			})
+		}
+	}
+	return result
+}
+
 // gradientPositions 按显式锚点补全渐变分段位置，保留原顺序
 // 入参: segments 渐变分段
 // 返回: []float64 分段位置

ofdgo_paint_mesh.go

@@ -230,7 +230,10 @@ func (r *Renderer) resolveMesh(fill *FillColor) (*MeshShading, error) {
 	vertices := make([]MeshVertex, len(points))
 	for i, point := range points {
 		space := point.Color.ColorSpace
-		kind, values := r.colorComponents(point.Color.Value, point.Color.Index, space)
+		kind, values, err := r.colorComponents(point.Color.Value, point.Color.Index, space)
+		if err != nil {
+			return nil, err
+		}
 		profile, err := r.Reader.colorProfile(r.colorDefinition(space))
 		if err != nil {
 			return nil, err
@@ -244,7 +247,11 @@ func (r *Renderer) resolveMesh(fill *FillColor) (*MeshShading, error) {
 	mesh := &MeshShading{}
 	if extend == 1 && back != nil {
 		space := back.ColorSpace
-		mesh.Background = r.ResolveColor(back.Value, back.Index, space, mergeAlpha(back.Alpha, fill.Alpha))
+		var err error
+		mesh.Background, err = r.ResolveColor(back.Value, back.Index, space, mergeAlpha(back.Alpha, fill.Alpha))
+		if err != nil {
+			return nil, err
+		}
 	}
 	for _, triangle := range indices {
 		mesh.Triangles = append(mesh.Triangles, [3]MeshVertex{vertices[triangle[0]], vertices[triangle[1]], vertices[triangle[2]]})
@@ -279,17 +286,14 @@ func (v MeshVertex) sameSpace(other MeshVertex) bool {
 // 入参: values 插值分量
 // 返回: float64 红、绿、蓝分量
 func (v MeshVertex) rgb(values [4]float64) (float64, float64, float64) {
-	if v.profile != nil {
-		for i := range values {
-			values[i] = math.Max(0, math.Min(1, values[i]))
-		}
-		rgb, err := v.profile.rgb(values)
-		if err != nil {
-			return 0, 0, 0
-		}
-		return rgb[0], rgb[1], rgb[2]
+	for i := range values {
+		values[i] = math.Max(0, math.Min(1, values[i]))
 	}
-	return meshRGB(v.Space, values)
+	rgb, err := displayColor(v.Space, values, v.profile)
+	if err != nil {
+		return 0, 0, 0
+	}
+	return rgb[0], rgb[1], rgb[2]
 }
 
 // meshTriangleIndices 校验控制点并生成共享边或格构三角形编号
@@ -344,14 +348,7 @@ func meshTriangleIndices(points []ShdPoint, columns, extend int) ([][3]int, erro
 // 入参: space 颜色模型, values 分量
 // 返回: float64 红、绿、蓝分量
 func meshRGB(space string, values [4]float64) (float64, float64, float64) {
-	switch space {
-	case "GRAY":
-		return values[0], values[0], values[0]
-	case "CMYK":
-		return (1 - values[0]) * (1 - values[3]), (1 - values[1]) * (1 - values[3]), (1 - values[2]) * (1 - values[3])
-	default:
-		return values[0], values[1], values[2]
-	}
+	return (MeshVertex{Space: space}).rgb(values)
 }
 
 // meshByte 将归一化颜色分量量化为八位整数

ofdgo_paint_model.go

@@ -93,6 +93,9 @@ func (r *Renderer) ResolvePaint(fill *FillColor) (Paint, error) {
 	if node := fill.AxialShd; node != nil {
 		start, end := parseFloats(node.StartPoint), parseFloats(node.EndPoint)
 		stops := r.renderGradientStops(node.Segment, fill.Alpha)
+		if r.renderError != nil {
+			return Paint{}, r.renderError
+		}
 		sample, err := r.profileGradient(node.Segment, fill.Alpha)
 		if err != nil {
 			return Paint{}, err
@@ -107,6 +110,9 @@ func (r *Renderer) ResolvePaint(fill *FillColor) (Paint, error) {
 	if node := fill.RadialShd; node != nil && node.EndRadius > 0 {
 		start, end := parseFloats(node.StartPoint), parseFloats(node.EndPoint)
 		stops := r.renderGradientStops(node.Segment, fill.Alpha)
+		if r.renderError != nil {
+			return Paint{}, r.renderError
+		}
 		sample, err := r.profileGradient(node.Segment, fill.Alpha)
 		if err != nil {
 			return Paint{}, err

ofdgo_paint_profile.go

@@ -41,7 +41,10 @@ func (r *Renderer) profileGradient(segments []ShdSegment, alpha *int) (func(floa
 	}
 	gradient := &profileGradient{positions: gradientPositions(segments), colors: make([]MeshVertex, len(segments))}
 	for i, segment := range segments {
-		kind, values := r.colorComponents(segment.Color.Value, segment.Color.Index, segment.Color.ColorSpace)
+		kind, values, err := r.colorComponents(segment.Color.Value, segment.Color.Index, segment.Color.ColorSpace)
+		if err != nil {
+			return nil, err
+		}
 		profile, err := r.Reader.colorProfile(r.colorDefinition(segment.Color.ColorSpace))
 		if err != nil {
 			return nil, err
@@ -63,7 +66,7 @@ func (g *profileGradient) At(t float64) color.RGBA {
 		return color.RGBA{}
 	}
 	first := g.colors[0]
-	if t <= g.positions[0] {
+	if t < g.positions[0] {
 		r, green, b := first.rgb(first.Values)
 		return profileColor([3]float64{r, green, b}, first.Alpha)
 	}

ofdgo_pdf.go

@@ -81,6 +81,7 @@ type pdfImporter struct {
 	clipTexts        map[*pdfgo.TextClip][]TextObject
 	clipPaths        *renderCache[[32]byte, pdfClipPath]
 	cmykSpace        string
+	rgbSpace         string
 	iccSpaces        map[pdfICCKey]string
 	objects          *pdfObjectBuffer
 	formResources    *pdfFormCache
@@ -173,7 +174,17 @@ func ImportPDF(ctx context.Context, source io.ReaderAt, size int64, options PDFI
 	}
 	defer reader.Close()
 	importer.reader = reader
+	outputIntents, err := reader.OutputIntents()
+	if err != nil {
+		return nil, PDFImportReport{}, fmt.Errorf("import PDF output intents: %w", err)
+	}
 	importer.report.Warnings = diagnostics
+	if len(outputIntents) != 0 {
+		if options.Strict {
+			return nil, PDFImportReport{}, &pdfgo.UnsupportedError{Feature: "PDF output intent conversion"}
+		}
+		importer.report.Warnings = append(importer.report.Warnings, pdfgo.Diagnostic{Message: "PDF output intents not transferred to OFD"})
+	}
 	importer.pageIndexes = make(map[pdfgo.Reference]int)
 	importer.resolveFile = options.ResolveFile
 	importer.resolveReference = options.ResolveReference

ofdgo_pdf_composite.go

@@ -948,7 +948,7 @@ func (p *pdfImporter) compositeRegion(backdrop []pdfCompositeNode, node pdfCompo
 						rgb, err = codecpdf.OutputColor(space, values)
 					}
 				} else if c.transfers != nil {
-					rgb, err = space.RGB(pixel.Values[:space.Components()], "RelativeColorimetric")
+					rgb, err = space.SRGB(pixel.Values[:space.Components()], "RelativeColorimetric")
 				} else {
 					if colorReady && pixel.Values == colorValues {
 						rgb = colorRGB

ofdgo_pdf_geometry.go

@@ -445,12 +445,22 @@ func (p *pdfImporter) appendPath(mark pdfgo.PathMark) error {
 		ctm = pdfNumbers(m[:]...)
 	}
 	paint := func(value pdfgo.Paint) (*FillColor, error) {
-		if value.Tiling != nil || pdfGradientPattern(value) {
-			return p.paintColor(value, box)
+		if value.Tiling == nil && value.Axial == nil && value.Radial == nil && value.Mesh == nil && value.Function == nil && value.Shading == nil {
+			return p.color(value, mark.Style.RenderingIntent)
 		}
-		return drawing.paintColor(value, origin)
+		if value.Tiling != nil || pdfGradientPattern(value) {
+			return p.paintColor(value, box, mark.Style.RenderingIntent)
+		}
+		return drawing.paintColor(value, origin, mark.Style.RenderingIntent)
+	}
+	fillColor, err := p.color(mark.Style.Fill, mark.Style.RenderingIntent)
+	if err != nil {
+		return err
+	}
+	strokePaint, err := p.color(mark.Style.Stroke, mark.Style.RenderingIntent)
+	if err != nil {
+		return err
 	}
-	fillColor, strokePaint := p.color(mark.Style.Fill), p.color(mark.Style.Stroke)
 	if mark.Fill {
 		fillColor, err = paint(mark.Style.Fill)
 		if err != nil {

ofdgo_pdf_group.go

@@ -32,8 +32,9 @@ var errPDFGroupRaster = errors.New("PDF transparency group requires local compos
 
 // pdfPaintRegion 保存透明组内的单色填充区域
 type pdfPaintRegion struct {
-	paint pdfgo.Paint
-	path  GeometryPath
+	paint  pdfgo.Paint
+	path   GeometryPath
+	intent pdfgo.Name
 }
 
 // group 将单色图元的透明组转换为互不重叠的填充区域，保留矢量与组不透明度
@@ -138,6 +139,7 @@ func (p *pdfImporter) groupPaths(mark pdfgo.GroupMark, walk func(pdfgo.Visitor)
 	var regions []pdfPaintRegion
 	var combined GeometryPath
 	var paint *pdfgo.Paint
+	var intent pdfgo.Name
 	var clips []pdfgo.Path
 	opaque := true
 	scale := math.Hypot(p.matrix[0], p.matrix[1])
@@ -182,12 +184,14 @@ func (p *pdfImporter) groupPaths(mark pdfgo.GroupMark, walk func(pdfgo.Visitor)
 			opaque = opaque && color.Alpha == 1
 			if paint == nil {
 				paint, clips = &color, path.Style.Clips
+				intent = path.Style.RenderingIntent
 			} else if !reflect.DeepEqual(clips, path.Style.Clips) {
 				return fmt.Errorf("%w: independently clipped group content", errPDFGroupRaster)
-			} else if color.Alpha != 1 || !reflect.DeepEqual(*paint, color) {
-				regions = append(regions, pdfPaintRegion{*paint, combined})
+			} else if color.Alpha != 1 || !reflect.DeepEqual(*paint, color) || intent != path.Style.RenderingIntent {
+				regions = append(regions, pdfPaintRegion{*paint, combined, intent})
 				combined = nil
 				paint = &color
+				intent = path.Style.RenderingIntent
 			}
 			outline := shape
 			evenOdd := path.Path.EvenOdd
@@ -251,7 +255,7 @@ func (p *pdfImporter) groupPaths(mark pdfgo.GroupMark, walk func(pdfgo.Visitor)
 	if len(combined) == 0 {
 		return nil
 	}
-	regions = append(regions, pdfPaintRegion{*paint, combined})
+	regions = append(regions, pdfPaintRegion{*paint, combined, intent})
 	if !opaque {
 		regions, err = pdfCompositeRegions(geometry, regions)
 		if err != nil {
@@ -301,7 +305,11 @@ func (p *pdfImporter) groupPaths(mark pdfgo.GroupMark, walk func(pdfgo.Visitor)
 		if err != nil {
 			return err
 		}
-		object := PathObject{Boundary: pdfBoundary(box), AbbreviatedData: data, Fill: &fill, Stroke: &stroke, FillColor: p.color(region.paint), Clips: objectClips}
+		color, err := p.color(region.paint, region.intent)
+		if err != nil {
+			return err
+		}
+		object := PathObject{Boundary: pdfBoundary(box), AbbreviatedData: data, Fill: &fill, Stroke: &stroke, FillColor: color, Clips: objectClips}
 		p.appendObject(GraphicObject{Type: "PathObject", PathObject: object})
 		p.report.PathObjects++
 	}
@@ -523,7 +531,7 @@ func pdfCompositeRegions(geometry GeometryBackend, regions []pdfPaintRegion) ([]
 				return nil, err
 			}
 			if len(outside) != 0 {
-				next = append(next, pdfPaintRegion{backdrop.paint, outside})
+				next = append(next, pdfPaintRegion{backdrop.paint, outside, backdrop.intent})
 			}
 			overlap, err := geometry.Combine(backdrop.path, source.path, GeometryIntersect)
 			if err != nil {
@@ -534,7 +542,7 @@ func pdfCompositeRegions(geometry GeometryBackend, regions []pdfPaintRegion) ([]
 				for i := range paint.RGB {
 					paint.RGB[i] = (source.paint.RGB[i]*source.paint.Alpha + backdrop.paint.RGB[i]*backdrop.paint.Alpha*(1-source.paint.Alpha)) / paint.Alpha
 				}
-				next = append(next, pdfPaintRegion{paint, overlap})
+				next = append(next, pdfPaintRegion{paint, overlap, ""})
 			}
 			remaining, err = geometry.Combine(remaining, backdrop.path, GeometrySubtract)
 			if err != nil {
@@ -542,7 +550,7 @@ func pdfCompositeRegions(geometry GeometryBackend, regions []pdfPaintRegion) ([]
 			}
 		}
 		if len(remaining) != 0 {
-			next = append(next, pdfPaintRegion{source.paint, remaining})
+			next = append(next, pdfPaintRegion{source.paint, remaining, source.intent})
 		}
 		result = next
 	}

ofdgo_pdf_image.go

@@ -106,12 +106,14 @@ func (p *pdfImporter) image(mark pdfgo.ImageMark) error {
 	}
 	if source.ImageMask {
 		fill := mark.Style.Fill.RGB
-		if values := mark.Style.Fill.CMYK; values != nil {
+		if space := mark.Style.Fill.Space; space != nil {
+			fill, err = space.SRGB(mark.Style.Fill.Values[:space.Components()], mark.Style.RenderingIntent)
+		} else if values := mark.Style.Fill.CMYK; values != nil {
 			space := &pdfgo.ColorSpace{Model: "DeviceCMYK"}
-			fill, err = space.RGB(values[:], mark.Style.RenderingIntent)
-			if err != nil {
-				return err
-			}
+			fill, err = space.SRGB(values[:], mark.Style.RenderingIntent)
+		}
+		if err != nil {
+			return err
 		}
 		key.tint = color.NRGBA64{
 			R: uint16(math.Round(fill[0] * 65535)),
@@ -145,41 +147,50 @@ func (p *pdfImporter) image(mark pdfgo.ImageMark) error {
 		}
 	}
 	if id == "" {
+		var data []byte
+		if !source.ImageMask && key.process == "" && p.compression.Mode != CompressionLossy {
+			data, err = codecpdf.EncodeCMYKTIFF(p.ctx, source)
+			if err != nil {
+				return err
+			}
+		}
 		var jbig2Original, jpegOriginal []byte
 		var decoded image.Image
-		if key.process != "" {
-			decoded, err = p.imageProcess(source, key.process)
-			if err != nil {
-				return err
-			}
-			if key.size != (image.Point{}) {
-				decoded, err = pdfgo.ResizeImage(p.ctx, decoded, key.size)
-				if err != nil {
-					return err
-				}
-			}
-		} else {
-			jbig2Original, err = source.JBIG2FileContext(p.ctx)
-			if err != nil {
-				return err
-			}
-			jpegOriginal, err = source.JPEGFileContext(p.ctx)
-			if err != nil {
-				return err
-			}
-			if len(jbig2Original) == 0 && len(jpegOriginal) == 0 && (source.ImageMask || key.size != (image.Point{})) {
-				decoded, err = source.DecodeImageSizeContext(p.ctx, key.size)
-				if err != nil {
-					return err
-				}
-			}
-		}
-		if source.ImageMask {
-			decoded = &codecpdf.StencilImage{Source: decoded, Fill: key.tint}
-		}
-		data := jbig2Original
 		if len(data) == 0 {
-			data = jpegOriginal
+			if key.process != "" {
+				decoded, err = p.imageProcess(source, key.process)
+				if err != nil {
+					return err
+				}
+				if key.size != (image.Point{}) {
+					decoded, err = pdfgo.ResizeImage(p.ctx, decoded, key.size)
+					if err != nil {
+						return err
+					}
+				}
+			} else {
+				jbig2Original, err = source.JBIG2FileContext(p.ctx)
+				if err != nil {
+					return err
+				}
+				jpegOriginal, err = source.JPEGFileContext(p.ctx)
+				if err != nil {
+					return err
+				}
+				if len(jbig2Original) == 0 && len(jpegOriginal) == 0 && (source.ImageMask || key.size != (image.Point{})) {
+					decoded, err = source.DecodeImageSizeContext(p.ctx, key.size)
+					if err != nil {
+						return err
+					}
+				}
+			}
+			if source.ImageMask {
+				decoded = &codecpdf.StencilImage{Source: decoded, Fill: key.tint}
+			}
+			data = jbig2Original
+			if len(data) == 0 {
+				data = jpegOriginal
+			}
 		}
 		optimized := false
 		if len(data) == 0 && decoded != nil && !source.ImageMask && p.compression.Mode == CompressionLossy {

ofdgo_pdf_mesh.go

@@ -166,7 +166,7 @@ func (p *pdfImporter) meshColor(paint pdfgo.Paint, box Box) (*FillColor, error)
 					shading.Point = append(shading.Point, ShdPoint{X: point.X - box.X, Y: point.Y - box.Y, EdgeFlag: flag, Color: ShdColor{Value: value, ColorSpace: icc}})
 					continue
 				}
-				rgb, err := mesh.Space.RGB(values[:mesh.Space.Components()], mesh.Intent)
+				rgb, err := mesh.Space.SRGB(values[:mesh.Space.Components()], mesh.Intent)
 				if err != nil {
 					return nil, err
 				}
@@ -174,7 +174,10 @@ func (p *pdfImporter) meshColor(paint pdfgo.Paint, box Box) (*FillColor, error)
 				if mesh.Space.Model == "DeviceCMYK" && !mesh.Space.Calibrated() {
 					color.CMYK = (*[4]float64)(values)
 				}
-				converted := p.color(color)
+				converted, err := p.color(color, mesh.Intent)
+				if err != nil {
+					return nil, err
+				}
 				shading.Point = append(shading.Point, ShdPoint{X: point.X - box.X, Y: point.Y - box.Y, EdgeFlag: flag, Color: ShdColor{Value: converted.Value, ColorSpace: converted.ColorSpace}})
 			}
 			previous.Points = triangle.Points
@@ -190,8 +193,8 @@ func (p *pdfImporter) meshColor(paint pdfgo.Paint, box Box) (*FillColor, error)
 		}
 		shading.Extend, shading.BackColor = 1, &background
 	}
-	color := p.color(paint)
-	color.Value = ""
+	alpha := int(math.Round(paint.Alpha * 255))
+	color := &FillColor{Alpha: &alpha}
 	color.GouraudShd = shading
 	return color, nil
 }

ofdgo_pdf_shading.go

@@ -158,7 +158,10 @@ func (p *pdfImporter) gradientSegments(stops []pdfgo.GradientStop, space *pdfgo.
 		if cmyk {
 			paint.CMYK = &stop.Values
 		}
-		color := p.color(paint)
+		color, err := p.color(paint, intent)
+		if err != nil {
+			return nil, err
+		}
 		segments[i] = ShdSegment{Position: stop.Position, Color: ShdColor{Value: color.Value, ColorSpace: color.ColorSpace}}
 	}
 	return segments, nil
@@ -283,7 +286,7 @@ func (p *pdfImporter) gradientPattern(paint pdfgo.Paint, box Box) (*FillColor, e
 	if _, ok := matrix.Inverse(); !ok {
 		return nil, fmt.Errorf("invalid PDF gradient bounds matrix")
 	}
-	fill, err := p.paintColor(plain, box)
+	fill, err := p.paintColor(plain, box, intent)
 	if err != nil {
 		return nil, err
 	}
@@ -337,7 +340,8 @@ func (p *pdfImporter) gradientPattern(paint pdfgo.Paint, box Box) (*FillColor, e
 			objects = append(objects, object)
 		}
 	}
-	color := p.color(paint)
+	alpha := int(math.Round(paint.Alpha * 255))
+	color := &FillColor{Alpha: &alpha}
 	color.Pattern = &Pattern{Width: box.W, Height: box.H, RelativeTo: "Page", CTM: pdfNumbers(1, 0, 0, 1, box.X, box.Y), CellContent: PatternContent{PathObject: objects}}
 	return color, nil
 }
@@ -352,7 +356,7 @@ func (p *pdfImporter) gradientBackgroundColor(values [4]float64, space *pdfgo.Co
 	stop := pdfgo.GradientStop{Values: values}
 	if !pdfICCTransfer(space) && (space.Model != "DeviceCMYK" || space.Calibrated()) {
 		var err error
-		stop.RGB, err = space.RGB(values[:space.Components()], intent)
+		stop.RGB, err = space.SRGB(values[:space.Components()], intent)
 		if err != nil {
 			return ShdColor{}, err
 		}
@@ -726,26 +730,55 @@ func pdfShadingClippedNode(node pdfCompositeNode, box pdfgo.Rectangle, matrix pd
 	return node
 }
 
-// color 保留设备色彩分量并复用文档颜色空间
-// 入参: paint PDF颜色与不透明度
-// 返回: *FillColor OFD颜色
-func (p *pdfImporter) color(paint pdfgo.Paint) *FillColor {
+// color 保留设备及ICC源分量，其他校准色以16位显示颜色输出
+// 入参: paint PDF颜色与不透明度, intent 实际渲染意图
+// 返回: *FillColor OFD颜色, error 配置或颜色转换错误
+func (p *pdfImporter) color(paint pdfgo.Paint, intent pdfgo.Name) (*FillColor, error) {
 	alpha := int(math.Round(paint.Alpha * 255))
-	if paint.CMYK != nil && (paint.Space == nil || !paint.Space.Calibrated()) {
+	if pdfICCTransfer(paint.Space) {
+		id, err := p.iccColorSpace(paint.Space, intent)
+		if err != nil {
+			return nil, err
+		}
+		value, err := pdfICCValues(paint.Values[:], paint.Space.Components())
+		if err != nil {
+			return nil, err
+		}
+		return &FillColor{ColorSpace: id, Value: value, Alpha: &alpha}, nil
+	}
+	cmyk := paint.CMYK
+	if cmyk == nil && paint.Space != nil && paint.Space.Model == "DeviceCMYK" && !paint.Space.Calibrated() {
+		cmyk = &paint.Values
+	}
+	if cmyk != nil && (paint.Space == nil || !paint.Space.Calibrated()) {
 		if p.cmykSpace == "" {
 			p.cmykSpace = p.editor.nextID()
 			p.editor.resources = append(p.editor.resources, editorResource{space: &ColorSpace{ID: p.cmykSpace, Type: "CMYK", BitsPerComponent: 16}})
 		}
-		v := paint.CMYK
-		return &FillColor{ColorSpace: p.cmykSpace, Value: pdfNumbers(math.Round(v[0]*65535), math.Round(v[1]*65535), math.Round(v[2]*65535), math.Round(v[3]*65535)), Alpha: &alpha}
+		v := cmyk
+		return &FillColor{ColorSpace: p.cmykSpace, Value: pdfNumbers(math.Round(v[0]*65535), math.Round(v[1]*65535), math.Round(v[2]*65535), math.Round(v[3]*65535)), Alpha: &alpha}, nil
 	}
-	return &FillColor{Value: pdfNumbers(math.Round(paint.RGB[0]*255), math.Round(paint.RGB[1]*255), math.Round(paint.RGB[2]*255)), Alpha: &alpha}
+	if paint.Space.Calibrated() {
+		if p.rgbSpace == "" {
+			id, err := p.editor.AddColorSpace(ColorSpace{Type: "RGB", BitsPerComponent: 16}, nil)
+			if err != nil {
+				return nil, err
+			}
+			p.rgbSpace = id
+		}
+		value, err := pdfICCValues(paint.RGB[:], 3)
+		if err != nil {
+			return nil, err
+		}
+		return &FillColor{ColorSpace: p.rgbSpace, Value: value, Alpha: &alpha}, nil
+	}
+	return &FillColor{Value: pdfNumbers(math.Round(paint.RGB[0]*255), math.Round(paint.RGB[1]*255), math.Round(paint.RGB[2]*255)), Alpha: &alpha}, nil
 }
 
 // paintColor 将页面渐变转换为对象局部坐标
-// 入参: paint PDF画刷, box 对象边界
+// 入参: paint PDF画刷, box 对象边界, intent 实际渲染意图
 // 返回: *FillColor OFD颜色或渐变, error 图案转换错误
-func (p *pdfImporter) paintColor(paint pdfgo.Paint, box Box) (*FillColor, error) {
+func (p *pdfImporter) paintColor(paint pdfgo.Paint, box Box, intent pdfgo.Name) (*FillColor, error) {
 	if err := p.gradientError(paint); err != nil {
 		return nil, err
 	}
@@ -755,7 +788,8 @@ func (p *pdfImporter) paintColor(paint pdfgo.Paint, box Box) (*FillColor, error)
 	if paint.Mesh != nil {
 		return p.meshColor(paint, box)
 	}
-	color := p.color(paint)
+	alpha := int(math.Round(paint.Alpha * 255))
+	color := &FillColor{Alpha: &alpha}
 	if paint.Tiling != nil {
 		pattern, err := p.tilingPattern(paint.Tiling, paint)
 		if err != nil {
@@ -798,7 +832,7 @@ func (p *pdfImporter) paintColor(paint pdfgo.Paint, box Box) (*FillColor, error)
 		return color, nil
 	}
 	if paint.Axial == nil {
-		return color, nil
+		return p.color(paint, intent)
 	}
 	gradient := paint.Axial
 	start := p.matrix.Apply(gradient.Start)

ofdgo_pdf_text.go

@@ -325,7 +325,7 @@ func (p *pdfImporter) text(mark pdfgo.TextMark) error {
 	}
 	object.Boundary = pdfBoundary(box)
 	if stroke && !outlineStroke {
-		strokePaint, err := p.paintColor(mark.Style.Stroke, box)
+		strokePaint, err := p.paintColor(mark.Style.Stroke, box, mark.Style.RenderingIntent)
 		if err != nil {
 			return err
 		}
@@ -339,9 +339,12 @@ func (p *pdfImporter) text(mark pdfgo.TextMark) error {
 	object.Fill = &fill
 	object.Stroke = &stroke
 	object.Visible = &visible
-	object.FillColor = p.color(mark.Style.Fill)
+	object.FillColor, err = p.color(mark.Style.Fill, mark.Style.RenderingIntent)
+	if err != nil {
+		return err
+	}
 	if fill && !outlineStroke {
-		object.FillColor, err = p.paintColor(mark.Style.Fill, box)
+		object.FillColor, err = p.paintColor(mark.Style.Fill, box, mark.Style.RenderingIntent)
 		if err != nil {
 			return err
 		}