From 03048750e08155210236368492e1f63fcd5fc752 Mon Sep 17 00:00:00 2001
From: xiaoqidun <xiaoqidun@gmail.com>
Date: Sun, 13 Sep 2026 17:19:47 +0800
Subject: [PATCH] =?UTF-8?q?feat(=E4=BC=98=E5=8C=96=E6=80=A7=E8=83=BD):=20?=
 =?UTF-8?q?=E4=BC=98=E5=8C=96=E5=AD=97=E4=BD=93=E5=A4=8D=E7=94=A8=E4=B8=8E?=
 =?UTF-8?q?JPEG=E5=AF=BC=E5=87=BA=EF=BC=8C=E7=B2=BE=E7=AE=80=E6=B8=B2?=
 =?UTF-8?q?=E6=9F=93=E4=BE=9D=E8=B5=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 internal/webui/webui.go  | 23 ++++++++++++++++++-----
 ofdgo_renderer_output.go | 13 ++++++++++---
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/internal/webui/webui.go b/internal/webui/webui.go
index 255bb62..80374f0 100644
--- a/internal/webui/webui.go
+++ b/internal/webui/webui.go
@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"fmt"
 	"image"
-	"image/color"
 	"image/draw"
 	"image/jpeg"
 	"image/png"
@@ -476,7 +475,7 @@ func (s *Session) ExportPage(index int, value string, dpi float64) ([]byte, Expo
 		if renderErr != nil {
 			return nil, ExportFormat{}, renderErr
 		}
-		err = jpeg.Encode(&buf, imageWithWhiteBackground(img), &jpeg.Options{Quality: 95})
+		err = jpeg.Encode(&buf, fillWhiteBackground(img), &jpeg.Options{Quality: 95})
 	}
 	if err != nil {
 		return nil, ExportFormat{}, err
@@ -667,13 +666,27 @@ func (s *Session) ExportPDF() ([]byte, error) {
 	return buf.Bytes(), nil
 }
 
-// imageWithWhiteBackground 填充图片白色背景
+// fillWhiteBackground 填充白色背景，复用当前导出图片的RGBA像素
 // 入参: img 图片对象
 // 返回: image.Image 图片对象
-func imageWithWhiteBackground(img image.Image) image.Image {
+func fillWhiteBackground(img image.Image) image.Image {
 	bounds := img.Bounds()
+	if rgba, ok := img.(*image.RGBA); ok {
+		for y := 0; y < bounds.Dy(); y++ {
+			row := rgba.Pix[y*rgba.Stride : y*rgba.Stride+bounds.Dx()*4]
+			for i := 0; i < len(row); i += 4 {
+				if alpha := 255 - row[i+3]; alpha != 0 {
+					row[i] += alpha
+					row[i+1] += alpha
+					row[i+2] += alpha
+					row[i+3] = 255
+				}
+			}
+		}
+		return rgba
+	}
 	dst := image.NewRGBA(bounds)
-	draw.Draw(dst, bounds, &image.Uniform{C: color.White}, image.Point{}, draw.Src)
+	draw.Draw(dst, bounds, image.White, image.Point{}, draw.Src)
 	draw.Draw(dst, bounds, img, bounds.Min, draw.Over)
 	return dst
 }
diff --git a/ofdgo_renderer_output.go b/ofdgo_renderer_output.go
index 2a9661b..42caf8e 100644
--- a/ofdgo_renderer_output.go
+++ b/ofdgo_renderer_output.go
@@ -21,9 +21,10 @@ import (
 	"io"
 
 	"github.com/tdewolff/canvas"
-	"github.com/tdewolff/canvas/renderers"
 	"github.com/tdewolff/canvas/renderers/pdf"
+	"github.com/tdewolff/canvas/renderers/ps"
 	"github.com/tdewolff/canvas/renderers/rasterizer"
+	"github.com/tdewolff/canvas/renderers/svg"
 	"golang.org/x/image/draw"
 	"golang.org/x/image/math/f64"
 )
@@ -88,7 +89,9 @@ func (r *Renderer) RenderToSVG(page *PageContent, writer io.Writer) error {
 	if err != nil {
 		return err
 	}
-	return c.Write(writer, renderers.SVG())
+	renderer := svg.New(writer, c.W, c.H, nil)
+	c.RenderTo(renderer)
+	return renderer.Close()
 }
 
 // replacePDFProducer 替换PDF的Producer属性
@@ -125,7 +128,11 @@ func (r *Renderer) RenderToEPS(page *PageContent, writer io.Writer) error {
 	if err != nil {
 		return err
 	}
-	return c.Write(writer, renderers.EPS())
+	options := ps.DefaultOptions
+	options.Format = ps.EncapsulatedPostScript
+	renderer := ps.New(writer, c.W, c.H, &options)
+	c.RenderTo(renderer)
+	return renderer.Close()
 }
 
 // RenderToMultiPagePDF 将整个文档导出为多页PDF