Improve handling of non-sRGB images

process.go

@@ -258,16 +258,24 @@ func transformImage(ctx context.Context, img *vipsImage, data []byte, po *proces
 		return err
 	}
 
+	iccImported := false
 	convertToLinear := conf.UseLinearColorspace && (scale != 1 || po.Dpr != 1)
 
-	if convertToLinear {
+	if convertToLinear || !img.IsSRGB() {
 		if err = img.ImportColourProfile(true); err != nil {
 			return err
 		}
+		iccImported = true
+	}
 
+	if convertToLinear {
 		if err = img.LinearColourspace(); err != nil {
 			return err
 		}
+	} else {
+		if err = img.RgbColourspace(); err != nil {
+			return err
+		}
 	}
 
 	hasAlpha := img.HasAlpha()
@@ -336,16 +344,16 @@ func transformImage(ctx context.Context, img *vipsImage, data []byte, po *proces
 
 	checkTimeout(ctx)
 
-	if convertToLinear {
-		if err = img.RgbColourspace(); err != nil {
-			return err
-		}
-	} else {
+	if !iccImported {
 		if err = img.ImportColourProfile(false); err != nil {
 			return err
 		}
 	}
 
+	if err = img.RgbColourspace(); err != nil {
+		return err
+	}
+
 	if hasAlpha && (po.Flatten || po.Format == imageTypeJPEG) {
 		if err = img.Flatten(po.Background); err != nil {
 			return err

vips.go

@@ -503,28 +503,28 @@ func (img *vipsImage) ImportColourProfile(evenSRGB bool) error {
 
 	profile := (*C.char)(nil)
 
-	if img.VipsImage.Type == C.VIPS_INTERPRETATION_sRGB {
-		// No embedded profile for sRGB, ignore
-		if C.vips_has_embedded_icc(img.VipsImage) == 0 {
-			return nil
-		}
-
-		// Don't import sRGB IEC61966 2.1 unless evenSRGB
-		if !evenSRGB && C.vips_icc_is_srgb_iec61966(img.VipsImage) != 0 {
-			return nil
-		}
-	} else if img.VipsImage.Type == C.VIPS_INTERPRETATION_CMYK && C.vips_has_embedded_icc(img.VipsImage) == 0 {
-		if C.vips_support_builtin_icc() != 0 {
-			profile = cachedCString("cmyk")
-		} else {
+	if C.vips_has_embedded_icc(img.VipsImage) == 0 {
+		// No embedded profile
+		// If vips doesn't have built-in profile, use profile built-in to imgproxy for CMYK
+		// TODO: Remove this. Supporting built-in profiles is pain, vips does it better
+		if img.VipsImage.Type == C.VIPS_INTERPRETATION_CMYK && C.vips_support_builtin_icc() == 0 {
 			p, err := cmykProfilePath()
 			if err != nil {
 				return err
 			}
 			profile = cachedCString(p)
+		} else {
+			// imgproxy doesn't have built-in profile for other interpretations,
+			// so we can't do anything here
+			return nil
 		}
 	}
 
+	// Don't import sRGB IEC61966 2.1 unless evenSRGB
+	if img.VipsImage.Type == C.VIPS_INTERPRETATION_sRGB && !evenSRGB && C.vips_icc_is_srgb_iec61966(img.VipsImage) != 0 {
+		return nil
+	}
+
 	if C.vips_icc_import_go(img.VipsImage, &tmp, profile) == 0 {
 		C.swap_and_clear(&img.VipsImage, tmp)
 	} else {
@@ -534,6 +534,10 @@ func (img *vipsImage) ImportColourProfile(evenSRGB bool) error {
 	return nil
 }
 
+func (img *vipsImage) IsSRGB() bool {
+	return img.VipsImage.Type == C.VIPS_INTERPRETATION_sRGB
+}
+
 func (img *vipsImage) LinearColourspace() error {
 	return img.Colorspace(C.VIPS_INTERPRETATION_scRGB)
 }
@@ -543,7 +547,7 @@ func (img *vipsImage) RgbColourspace() error {
 }
 
 func (img *vipsImage) Colorspace(colorspace C.VipsInterpretation) error {
-	if C.vips_image_guess_interpretation(img.VipsImage) != colorspace {
+	if img.VipsImage.Type != colorspace {
 		var tmp *C.VipsImage
 
 		if C.vips_colourspace_go(img.VipsImage, &tmp, colorspace) != 0 {