flag imageinfo as srgb

src/ports/SkImageDecoder_CG.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCGUtils.h"
 #include "SkColorPriv.h"
 #include "SkImageDecoder.h"
@@ skipping 87 matching lines @@
     char* row = (char*)bm->getPixels();
     for (int y = 0; y < bm->height(); ++y) {
         proc(row, bm->width());
         row += bm->rowBytes();
     }
     bm->setAlphaType(kOpaque_SkAlphaType);
 }
 
 #define BITMAP_INFO (kCGBitmapByteOrder32Big | kCGImageAlphaPremultipliedLast)
 
+static bool icc_profile_is_sRGB(const void* data, size_t length) {
+    // found by inspection -- need a cleaner way to sniff a profile
+    const size_t ICC_PROFILE_OFFSET_TO_SRGB_TAG = 52;
+
+    if (length >= ICC_PROFILE_OFFSET_TO_SRGB_TAG + 4) {
+        return !memcmp((const char*)data + ICC_PROFILE_OFFSET_TO_SRGB_TAG, "sRGB", 4);
+    }
+    return false;
+}
+
 SkImageDecoder::Result SkImageDecoder_CG::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
     CGImageSourceRef imageSrc = SkStreamToCGImageSource(stream);
 
     if (NULL == imageSrc) {
         return kFailure;
     }
     SkAutoTCallVProc<const void, CFRelease> arsrc(imageSrc);
 
     CGImageRef image = CGImageSourceCreateImageAtIndex(imageSrc, 0, NULL);
     if (NULL == image) {
         return kFailure;
     }
     SkAutoTCallVProc<CGImage, CGImageRelease> arimage(image);
 
     const int width = SkToInt(CGImageGetWidth(image));
     const int height = SkToInt(CGImageGetHeight(image));
+    SkColorProfileType cpType = kLinear_SkColorProfileType;
 
-    bm->setInfo(SkImageInfo::MakeN32Premul(width, height));
+    CGColorSpaceRef cs = CGImageGetColorSpace(image);
+    if (cs) {
+        CGColorSpaceModel m = CGColorSpaceGetModel(cs);
+        if (kCGColorSpaceModelRGB == m) {
+            CFDataRef data = CGColorSpaceCopyICCProfile(cs);
+            if (data && icc_profile_is_sRGB(CFDataGetBytePtr(data), CFDataGetLength(data))) {
+                cpType = kSRGB_SkColorProfileType;
+                CFRelease(data);
+            }
+        }
+    }
+
+    bm->setInfo(SkImageInfo::MakeN32Premul(width, height, cpType));
     if (SkImageDecoder::kDecodeBounds_Mode == mode) {
         return kSuccess;
     }
 
     if (!this->allocPixelRef(bm, NULL)) {
         return kFailure;
     }
 
     SkAutoLockPixels alp(*bm);
 
@@ skipping 212 matching lines @@
 
     SkAutoTCallVProc<const void, CFRelease> arsrc(imageSrc);
     const CFStringRef name = CGImageSourceGetType(imageSrc);
     if (NULL == name) {
         return SkImageDecoder::kUnknown_Format;
     }
     return UTType_to_Format(name);
 }
 
 static SkImageDecoder_FormatReg gFormatReg(get_format_cg);