Reland "Properly set alpha type in webp decode."
Also use the newer setConfig function.
Add a test to confirm that we set the alpha type properly.
Add some images with alpha for testing. (These images are also
beneficial for the compare_unpremul test, which was previously
not meaningful on 100% opaque images.)
All of the added images are in the public domain. They were
taken from https://developers.google.com/speed/webp/gallery2:
yellow_rose:
"Free Stock Photo in High Resolution - Yellow Rose 3 - Flowers"
Image Author: Jon Sullivan
This file is in the public domain.
http://www.public-domain-photos.com/free-stock-photos-4/flowers/yellow-rose-3.jpg
baby_tux:
"baby tux for my user page"
Image Author: Fizyplankton
This file is in the public domain.
http://www.minecraftwiki.net/images/8/85/Fizyplankton.png
NOTRY=true
TBR=halcanary@google.com
BUG=skia:2388
Author: scroggo@google.com
Review URL: https://codereview.chromium.org/252423008
git-svn-id: http://skia.googlecode.com/svn/trunk@14360 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/ImageDecodingTest.cpp b/tests/ImageDecodingTest.cpp
index 5d52f90..e9348fe 100644
--- a/tests/ImageDecodingTest.cpp
+++ b/tests/ImageDecodingTest.cpp
@@ -163,6 +163,162 @@
}
}
+#if defined(SK_BUILD_FOR_ANDROID) || defined(SK_BUILD_FOR_UNIX)
+// Test that the alpha type is what we expect.
+static void test_alphaType(skiatest::Reporter* reporter, const SkString& filename,
+ bool requireUnpremul) {
+ SkBitmap bm;
+ SkFILEStream stream(filename.c_str());
+
+ SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(&stream));
+ if (NULL == decoder.get()) {
+ return;
+ }
+
+ decoder->setRequireUnpremultipliedColors(requireUnpremul);
+
+ // Decode just the bounds. This should always succeed.
+ bool success = decoder->decode(&stream, &bm, SkBitmap::kARGB_8888_Config,
+ SkImageDecoder::kDecodeBounds_Mode);
+ REPORTER_ASSERT(reporter, success);
+ if (!success) {
+ return;
+ }
+
+ // Keep track of the alpha type for testing later. If the full decode
+ // succeeds, the alpha type should be the same, unless the full decode
+ // determined that the alpha type should actually be opaque, which may
+ // not be known when only decoding the bounds.
+ const SkAlphaType boundsAlphaType = bm.alphaType();
+
+ // rewind should always succeed on SkFILEStream.
+ success = stream.rewind();
+ REPORTER_ASSERT(reporter, success);
+ if (!success) {
+ return;
+ }
+
+ success = decoder->decode(&stream, &bm, SkBitmap::kARGB_8888_Config,
+ SkImageDecoder::kDecodePixels_Mode);
+
+ if (!success) {
+ // When the decoder is set to require unpremul, if it does not support
+ // unpremul it will fail. This is the only reason the decode should
+ // fail (since we know the files we are using to test can be decoded).
+ REPORTER_ASSERT(reporter, requireUnpremul);
+ return;
+ }
+
+ // The bounds decode should return with either the requested
+ // premul/unpremul or opaque, if that value could be determined when only
+ // decoding the bounds.
+ if (requireUnpremul) {
+ REPORTER_ASSERT(reporter, kUnpremul_SkAlphaType == boundsAlphaType
+ || kOpaque_SkAlphaType == boundsAlphaType);
+ } else {
+ REPORTER_ASSERT(reporter, kPremul_SkAlphaType == boundsAlphaType
+ || kOpaque_SkAlphaType == boundsAlphaType);
+ }
+
+ // When decoding the full image, the alpha type should match the one
+ // returned by the bounds decode, unless the full decode determined that
+ // the alpha type is actually opaque.
+ REPORTER_ASSERT(reporter, bm.alphaType() == boundsAlphaType
+ || bm.alphaType() == kOpaque_SkAlphaType);
+}
+
+DEF_TEST(ImageDecoding_alphaType, reporter) {
+ SkString resourcePath = skiatest::Test::GetResourcePath();
+ if (resourcePath.isEmpty()) {
+ SkDebugf("Could not run alphaType test because resourcePath not specified.");
+ return;
+ }
+
+ SkOSFile::Iter iter(resourcePath.c_str());
+ SkString basename;
+ if (iter.next(&basename)) {
+ do {
+ SkString filename = SkOSPath::SkPathJoin(resourcePath.c_str(), basename.c_str());
+ for (int truth = 0; truth <= 1; ++truth) {
+ test_alphaType(reporter, filename, SkToBool(truth));
+ }
+ } while (iter.next(&basename));
+ } else {
+ SkDebugf("Failed to find any files :(\n");
+ }
+
+}
+
+// Using known images, test that decoding into unpremul and premul behave as expected.
+DEF_TEST(ImageDecoding_unpremul, reporter) {
+ SkString resourcePath = skiatest::Test::GetResourcePath();
+ if (resourcePath.isEmpty()) {
+ SkDebugf("Could not run unpremul test because resourcePath not specified.");
+ return;
+ }
+ const char* root = "half-transparent-white-pixel";
+ const char* suffixes[] = { ".png", ".webp" };
+
+ for (size_t i = 0; i < SK_ARRAY_COUNT(suffixes); ++i) {
+ SkString basename = SkStringPrintf("%s%s", root, suffixes[i]);
+ SkString fullName = SkOSPath::SkPathJoin(resourcePath.c_str(), basename.c_str());
+
+ SkBitmap bm;
+ SkFILEStream stream(fullName.c_str());
+
+ if (!stream.isValid()) {
+ SkDebugf("file %s missing from resource directoy %s\n",
+ basename.c_str(), resourcePath.c_str());
+ continue;
+ }
+
+ // This should never fail since we know the images we're decoding.
+ SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(&stream));
+ REPORTER_ASSERT(reporter, NULL != decoder.get());
+ if (NULL == decoder.get()) {
+ continue;
+ }
+
+ // Test unpremultiplied. We know what color this should result in.
+ decoder->setRequireUnpremultipliedColors(true);
+ bool success = decoder->decode(&stream, &bm, SkBitmap::kARGB_8888_Config,
+ SkImageDecoder::kDecodePixels_Mode);
+ REPORTER_ASSERT(reporter, success);
+ if (!success) {
+ continue;
+ }
+
+ REPORTER_ASSERT(reporter, bm.width() == 1 && bm.height() == 1);
+ {
+ SkAutoLockPixels alp(bm);
+ REPORTER_ASSERT(reporter, bm.getAddr32(0, 0)[0] == 0x7fffffff);
+ }
+
+ success = stream.rewind();
+ REPORTER_ASSERT(reporter, success);
+ if (!success) {
+ continue;
+ }
+
+ // Test premultiplied. Once again, we know which color this should
+ // result in.
+ decoder->setRequireUnpremultipliedColors(false);
+ success = decoder->decode(&stream, &bm, SkBitmap::kARGB_8888_Config,
+ SkImageDecoder::kDecodePixels_Mode);
+ REPORTER_ASSERT(reporter, success);
+ if (!success) {
+ continue;
+ }
+
+ REPORTER_ASSERT(reporter, bm.width() == 1 && bm.height() == 1);
+ {
+ SkAutoLockPixels alp(bm);
+ REPORTER_ASSERT(reporter, bm.getAddr32(0, 0)[0] == 0x7f7f7f7f);
+ }
+ }
+}
+#endif // SK_BUILD_FOR_UNIX/ANDROID skbug.com/2388
+
#ifdef SK_DEBUG
// Create a stream containing a bitmap encoded to Type type.
static SkMemoryStream* create_image_stream(SkImageEncoder::Type type) {
