mirror of
https://github.com/xiaoqidun/ofdgo.git
synced 2026-10-29 17:27:08 +08:00
85 lines
3.1 KiB
Go
85 lines
3.1 KiB
Go
// 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 ofdgo
|
|
|
|
import (
|
|
"fmt"
|
|
"image"
|
|
|
|
codecpdf "github.com/xiaoqidun/ofdgo/internal/codec/pdf"
|
|
"github.com/xiaoqidun/pdfgo"
|
|
)
|
|
|
|
// imageProcessModel 选择与页面原生过程色一致的图像输出，已等价的备用色沿用现有编码路径
|
|
// 入参: source 源图像
|
|
// 返回: pdfgo.Name 原生输出空间，无需重映射时为空, error 色料解析错误
|
|
func (p *pdfImporter) imageProcessModel(source *pdfgo.Image) (pdfgo.Name, error) {
|
|
space := p.compositeSpace
|
|
if source.ImageMask || !space.Device() {
|
|
return "", nil
|
|
}
|
|
colorants, err := source.ColorantSpace()
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
process := colorants.PrepareProcess(&pdfgo.ColorantDevice{Space: space}, space, false)
|
|
if process == nil || process.Mask() == ([4]bool{}) || process.AlternateEquivalent() {
|
|
return "", nil
|
|
}
|
|
return space.Model, nil
|
|
}
|
|
|
|
// imageProcess 复用源分量并保留原始分辨率，颜色变换随编码逐像素执行
|
|
// 入参: source 源图像, model 原生设备空间
|
|
// 返回: image.Image 只读图像, error 解码或分量映射错误
|
|
func (p *pdfImporter) imageProcess(source *pdfgo.Image, model pdfgo.Name) (image.Image, error) {
|
|
cache := p.compositingCache()
|
|
space := &pdfgo.ColorSpace{Model: model}
|
|
process, err := cache.imageProcess(p, source, space, false)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if process == nil {
|
|
return nil, fmt.Errorf("invalid native PDF image process space %s", model)
|
|
}
|
|
return &codecpdf.NativeImage{Source: process, Space: space}, nil
|
|
}
|
|
|
|
// imageProcess 复用同组原生采样，仅在需要备用颜色时保留完整分量
|
|
// 入参: importer 导入器, source 源图像, space 组混合空间, softMask 是否用于软蒙版
|
|
// 返回: *pdfgo.ImageProcess 原生采样，需要备用色时为nil, error 解码或布局错误
|
|
func (c *pdfCompositeCache) imageProcess(importer *pdfImporter, source *pdfgo.Image, space *pdfgo.ColorSpace, softMask bool) (*pdfgo.ImageProcess, error) {
|
|
key := pdfImageProcessKey{image: source, space: space, softMask: softMask}
|
|
if process, found := c.imageProcesses[key]; found {
|
|
return process, nil
|
|
}
|
|
device := &pdfgo.ColorantDevice{Space: space}
|
|
var process *pdfgo.ImageProcess
|
|
var err error
|
|
if components := c.images[source]; components != nil {
|
|
process, err = components.PrepareProcess(device, space, softMask)
|
|
} else {
|
|
process, err = source.DecodeProcessContext(importer.ctx, device, space, softMask)
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if c.imageProcesses == nil {
|
|
c.imageProcesses = make(map[pdfImageProcessKey]*pdfgo.ImageProcess)
|
|
}
|
|
c.imageProcesses[key] = process
|
|
return process, nil
|
|
}
|