Add --reverse-byte-order flag to pdfium_diff.
Allow pdfium_diff to decode BGRA images if desired, instead of always
assuming images are RGBA.
Bug: pdfium:994
Change-Id: I2322ffaea2b640a0d5b5f68aaccd502b367eb661
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/62591
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/testing/image_diff/image_diff.cpp b/testing/image_diff/image_diff.cpp
index f988e71..366990e 100644
--- a/testing/image_diff/image_diff.cpp
+++ b/testing/image_diff/image_diff.cpp
@@ -49,26 +49,12 @@
// Creates the image from the given filename on disk, and returns true on
// success.
bool CreateFromFilename(const std::string& path) {
- FILE* f = fopen(path.c_str(), "rb");
- if (!f)
- return false;
+ return CreateFromFilenameImpl(path, /*reverse_byte_order=*/false);
+ }
- std::vector<unsigned char> compressed;
- const size_t kBufSize = 1024;
- unsigned char buf[kBufSize];
- size_t num_read = 0;
- while ((num_read = fread(buf, 1, kBufSize, f)) > 0) {
- compressed.insert(compressed.end(), buf, buf + num_read);
- }
-
- fclose(f);
-
- data_ = image_diff_png::DecodePNG(compressed, &w_, &h_);
- if (data_.empty()) {
- Clear();
- return false;
- }
- return true;
+ // Same as CreateFromFilename(), but with BGRA instead of RGBA ordering.
+ bool CreateFromFilenameWithReverseByteOrder(const std::string& path) {
+ return CreateFromFilenameImpl(path, /*reverse_byte_order=*/true);
}
void Clear() {
@@ -92,6 +78,30 @@
}
private:
+ bool CreateFromFilenameImpl(const std::string& path,
+ bool reverse_byte_order) {
+ FILE* f = fopen(path.c_str(), "rb");
+ if (!f)
+ return false;
+
+ std::vector<unsigned char> compressed;
+ const size_t kBufSize = 1024;
+ unsigned char buf[kBufSize];
+ size_t num_read = 0;
+ while ((num_read = fread(buf, 1, kBufSize, f)) > 0) {
+ compressed.insert(compressed.end(), buf, buf + num_read);
+ }
+
+ fclose(f);
+
+ data_ = image_diff_png::DecodePNG(compressed, reverse_byte_order, &w_, &h_);
+ if (data_.empty()) {
+ Clear();
+ return false;
+ }
+ return true;
+ }
+
bool pixel_in_bounds(int x, int y) const {
return x >= 0 && x < w_ && y >= 0 && y < h_;
}
@@ -187,10 +197,12 @@
fprintf(
stderr,
"Usage:\n"
- " image_diff [--histogram] <compare file> <reference file>\n"
+ " image_diff OPTIONS <compare file> <reference file>\n"
" Compares two files on disk, returning 0 when they are the same;\n"
- " passing \"--histogram\" additionally calculates a diff of the\n"
- " RGBA value histograms (which is resistant to shifts in layout)\n"
+ " Passing \"--histogram\" additionally calculates a diff of the\n"
+ " RGBA value histograms. (which is resistant to shifts in layout)\n"
+ " Passing \"--reverse-byte-order\" additionally assumes the compare\n"
+ " file has BGRA byte ordering.\n"
" image_diff --diff <compare file> <reference file> <output file>\n"
" Compares two files on disk, outputs an image that visualizes the\n"
" difference to <output file>\n");
@@ -198,11 +210,16 @@
int CompareImages(const std::string& file1,
const std::string& file2,
- bool compare_histograms) {
+ bool compare_histograms,
+ bool reverse_byte_order) {
Image actual_image;
Image baseline_image;
- if (!actual_image.CreateFromFilename(file1)) {
+ bool actual_load_result =
+ reverse_byte_order
+ ? actual_image.CreateFromFilenameWithReverseByteOrder(file1)
+ : actual_image.CreateFromFilename(file1);
+ if (!actual_load_result) {
fprintf(stderr, "image_diff: Unable to open file \"%s\"\n", file1.c_str());
return kStatusError;
}
@@ -300,6 +317,7 @@
bool histograms = false;
bool produce_diff_image = false;
+ bool reverse_byte_order = false;
std::string filename1;
std::string filename2;
std::string diff_filename;
@@ -313,6 +331,8 @@
histograms = true;
} else if (strcmp(arg, "--diff") == 0) {
produce_diff_image = true;
+ } else if (strcmp(arg, "--reverse-byte-order") == 0) {
+ reverse_byte_order = true;
}
}
if (i < argc)
@@ -327,7 +347,7 @@
return DiffImages(filename1, filename2, diff_filename);
}
} else if (!filename2.empty()) {
- return CompareImages(filename1, filename2, histograms);
+ return CompareImages(filename1, filename2, histograms, reverse_byte_order);
}
PrintHelp();
diff --git a/testing/image_diff/image_diff_png.cpp b/testing/image_diff/image_diff_png.cpp
index eec8a04..2336b29 100644
--- a/testing/image_diff/image_diff_png.cpp
+++ b/testing/image_diff/image_diff_png.cpp
@@ -660,9 +660,11 @@
} // namespace
std::vector<unsigned char> DecodePNG(pdfium::span<const unsigned char> input,
+ bool reverse_byte_order,
int* width,
int* height) {
- return Decode(input.data(), input.size(), FORMAT_RGBA, width, height);
+ ColorFormat format = reverse_byte_order ? FORMAT_BGRA : FORMAT_RGBA;
+ return Decode(input.data(), input.size(), format, width, height);
}
std::vector<unsigned char> EncodeBGRPNG(const unsigned char* input,
diff --git a/testing/image_diff/image_diff_png.h b/testing/image_diff/image_diff_png.h
index 3afbd6a..911e2f0 100644
--- a/testing/image_diff/image_diff_png.h
+++ b/testing/image_diff/image_diff_png.h
@@ -13,8 +13,10 @@
namespace image_diff_png {
-// Decode a PNG into an RGBA pixel array.
+// Decode a PNG into an RGBA pixel array, or BGRA pixel array if
+// |reverse_byte_order| is set to true.
std::vector<unsigned char> DecodePNG(pdfium::span<const unsigned char> input,
+ bool reverse_byte_order,
int* width,
int* height);
