avoid turning grayscale inputs into sRGB by normalizing

lovell · Apr 16, 2015 · a0788a0 · a0788a0
1 parent b688993
commit a0788a0
Showing 1 changed file with 16 additions and 5 deletions.
diff --git a/src/resize.cc b/src/resize.cc
@@ -698,6 +698,11 @@ class ResizeWorker : public NanAsyncWorker {
 
     // Apply normalization
     if (baton->normalize) {
+      VipsInterpretation typeBeforeNormalize = image->Type;
+      if (typeBeforeNormalize == VIPS_INTERPRETATION_RGB) {
+        typeBeforeNormalize = VIPS_INTERPRETATION_sRGB;
+      }
+
       // normalize the luminance band in LAB space:
       VipsImage *lab;
       if (vips_colourspace(image, &lab, VIPS_INTERPRETATION_LAB, NULL)) {
@@ -739,6 +744,12 @@ class ResizeWorker : public NanAsyncWorker {
       }
       vips_object_local(hook, normalized);
 
+      VipsImage *origFormat;
+      if (vips_colourspace(normalized, &origFormat, typeBeforeNormalize, NULL)) {
+        return Error();
+      }
+      vips_object_local(hook, origFormat);
+
       if (HasAlpha(image)) {
         VipsImage *alpha;
         if (vips_extract_band(image, &alpha, image->Bands - 1, "n", 1, NULL)) {
@@ -747,18 +758,18 @@ class ResizeWorker : public NanAsyncWorker {
         vips_object_local(hook, alpha);
 
         VipsImage *normalizedAlpha;
-        if (vips_bandjoin2(normalized, alpha, &normalizedAlpha, NULL)) {
+        if (vips_bandjoin2(origFormat, alpha, &normalizedAlpha, NULL)) {
           return Error();
         }
         vips_object_local(hook, normalizedAlpha);
         image = normalizedAlpha;
       } else {
-        image = normalized;
+        image = origFormat;
       }
     }
 
     // Convert image to sRGB, if not already
-    if (image->Type != VIPS_INTERPRETATION_sRGB) {
+    if (image->Type != VIPS_INTERPRETATION_sRGB && image->Type != VIPS_INTERPRETATION_B_W) {
       // Switch intrepretation to sRGB
       VipsImage *rgb;
       if (vips_colourspace(image, &rgb, VIPS_INTERPRETATION_sRGB, NULL)) {
@@ -825,10 +836,10 @@ class ResizeWorker : public NanAsyncWorker {
 #if (VIPS_MAJOR_VERSION >= 8 || (VIPS_MAJOR_VERSION >= 7 && VIPS_MINOR_VERSION >= 42))
     } else if (baton->output == "__raw") {
       // Write raw, uncompressed image data to buffer
-      if (baton->greyscale) {
+      if (baton->greyscale || image->Type == VIPS_INTERPRETATION_B_W) {
         // Extract first band for greyscale image
         VipsImage *grey;
-        if (vips_extract_band(image, &grey, 1, NULL)) {
+        if (vips_extract_band(image, &grey, 0, NULL)) {
           return Error();
         }
         vips_object_local(hook, grey);