feat(转换能力): 修复透明合成与遮罩识别

go.mod

@@ -10,7 +10,7 @@ require (
 	github.com/tdewolff/canvas v0.0.0-20260923214215-09804640d00c
 	github.com/tdewolff/font v0.0.0-20260913163313-54f98bb59ee6
 	github.com/xiaoqidun/jbig2 v1.1.1
-	github.com/xiaoqidun/pdfgo v0.0.0-20261008072006-d519e7a38749
+	github.com/xiaoqidun/pdfgo v0.0.0-20261008074859-a724a7b51281
 	golang.org/x/crypto v0.57.0
 	golang.org/x/image v0.46.0
 	golang.org/x/text v0.42.0

go.sum

@@ -62,8 +62,8 @@ github.com/tdewolff/test v1.0.12 h1:7F21DqIajswxuche0geHdrUZRCWE4oko4b7bcmkkrxk=
 github.com/tdewolff/test v1.0.12/go.mod h1:XPuWBzvdUzhCuxWO1ojpXsyzsA5bFoS3tO/Q3kFuTG8=
 github.com/xiaoqidun/jbig2 v1.1.1 h1:SjliS9ZO0e9HX5oYUfBuXrfFsXhWricrSz+XY4zORDI=
 github.com/xiaoqidun/jbig2 v1.1.1/go.mod h1:8QonVWtENmh2kc6l+leqeGl7psb79DWlHDkCpdChjfQ=
-github.com/xiaoqidun/pdfgo v0.0.0-20261008072006-d519e7a38749 h1:jWImuld2SXZp826sudLJJUUOEEMPj/Jy77ItAE778Sg=
-github.com/xiaoqidun/pdfgo v0.0.0-20261008072006-d519e7a38749/go.mod h1:4Pf0JO0BEf1uzRY+uZjlMjN/OPn3PYa0YMi6cqPPTLQ=
+github.com/xiaoqidun/pdfgo v0.0.0-20261008074859-a724a7b51281 h1:xtRrxDRoPCN+IzqaAC8BR334Uif9VScpwTa4fk2gfBg=
+github.com/xiaoqidun/pdfgo v0.0.0-20261008074859-a724a7b51281/go.mod h1:4Pf0JO0BEf1uzRY+uZjlMjN/OPn3PYa0YMi6cqPPTLQ=
 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=

ofdgo_pdf_composite.go

@@ -613,37 +613,38 @@ func (p *pdfImporter) compositeObjects(nodes []pdfCompositeNode) error {
 
 // opaque 检查图元是否无需与页面背景混合
 // 入参: space 当前混合空间
-// 返回: bool 是否可直接保留
-func (n pdfCompositeNode) opaque(space *pdfgo.ColorSpace) bool {
+// 返回: bool 是否可直接保留, error 遮罩解析错误
+func (n pdfCompositeNode) opaque(space *pdfgo.ColorSpace) (bool, error) {
 	if n.group != nil {
 		g := n.group
 		if g.Knockout && n.textObject == nil || g.Alpha != 1 || g.SoftMask != nil || !pdfNormalBlend(g.BlendMode) || g.ColorSpace != nil && !g.ColorSpace.Equal(space) {
-			return false
+			return false, nil
 		}
 		for _, child := range n.children {
-			if !child.opaque(space) {
-				return false
+			if opaque, err := child.opaque(space); err != nil || !opaque {
+				return false, err
 			}
 		}
-		return true
+		return true, nil
 	}
 	style, fill, stroke := n.style()
 	if n.image != nil && style.FillOverprint {
-		return false
+		return false, nil
 	}
 	if style.SoftMask != nil || !pdfNormalBlend(style.BlendMode) || fill && style.Fill.Alpha != 1 || stroke && style.Stroke.Alpha != 1 {
-		return false
+		return false, nil
 	}
 	if fill && style.FillOverprint && pdfOverprintNeedsSeparation(style.Fill) || stroke && style.StrokeOverprint && pdfOverprintNeedsSeparation(style.Stroke) {
-		return false
+		return false, nil
 	}
 	if fill && pdfGradientError(style.Fill) != nil || stroke && pdfGradientError(style.Stroke) != nil {
-		return false
+		return false, nil
 	}
-	if n.image != nil && (n.image.Image.Mask != nil || n.image.Image.SoftMask != nil) {
-		return false
+	if n.image != nil {
+		masked, err := n.image.Image.HasMask()
+		return !masked, err
 	}
-	return true
+	return true, nil
 }
 
 // direct 检查sRGB图元能否使用标准OFD透明度而无需背景合成

ofdgo_pdf_composite_pattern.go

@@ -228,7 +228,7 @@ func (p *pdfImporter) compositePattern(paint pdfgo.Paint) (*pdfCompositePattern,
 
 // directCompositeNode 检查图元、透明组和图案单元能否独立保留，逐层核对背景混合
 // 入参: node 图元, space 混合空间
-// 返回: bool 是否可直接转换, error 图案解析错误
+// 返回: bool 是否可直接转换, error 图案或遮罩解析错误
 func (p *pdfImporter) directCompositeNode(node pdfCompositeNode, space *pdfgo.ColorSpace) (bool, error) {
 	if node.group == nil && space.Device() {
 		style, fill, stroke := node.style()
@@ -290,7 +290,11 @@ func (p *pdfImporter) directCompositeNode(node pdfCompositeNode, space *pdfgo.Co
 	if group := node.group; group != nil && !group.Knockout && group.Alpha == 1 && group.SoftMask == nil && pdfNormalBlend(group.BlendMode) && (group.ColorSpace == nil || group.ColorSpace.SRGBEquivalent()) {
 		directGroup = true
 	}
-	if !node.opaque(space) && !(space.SRGBEquivalent() && (directGroup || node.direct())) {
+	opaque, err := node.opaque(space)
+	if err != nil {
+		return false, err
+	}
+	if !opaque && !(space.SRGBEquivalent() && (directGroup || node.direct())) {
 		if node.textObject != nil && space.SRGBEquivalent() {
 			for _, child := range node.children {
 				if direct, err := p.directCompositeNode(child, space); err != nil || !direct {

ofdgo_pdf_group.go

@@ -101,7 +101,11 @@ func pdfOpaqueVisitor(visitor pdfgo.Visitor) pdfgo.Visitor {
 			return check(m.Style, m.Mode%4 == 0 || m.Mode%4 == 2, m.Mode%4 == 1 || m.Mode%4 == 2)
 		},
 		Image: func(m pdfgo.ImageMark) error {
-			if m.Image.ImageMask || m.Image.Mask != nil || m.Image.SoftMask != nil || m.Image.Stream.Dictionary["SMaskInData"] != nil {
+			masked, err := m.Image.HasMask()
+			if err != nil {
+				return err
+			}
+			if masked {
 				return &pdfgo.UnsupportedError{Feature: "non-sRGB masked group image"}
 			}
 			return check(m.Style, true, false)