Test region decoding in skimage, plus fixes.

Add tests in skimage to perform region decoding. Write out a
PNG of the region as well as a bitmap obtained with extractSubset
for comparison.

Rename decodeRegion to decodeSubset, so it will not be confused
with SkRegion. (Leave a function called decodeRegion which calls
decodeSubset.)

Clean up some comments.

Use png_set_interlaced_pass instead of modifying pass directly.

Make some changes to region decoding to fix problems I discovered
during testing:

Only call getAddr within a valid range.
Check for a NULL fInputStream.
Return a boolean for whether cropBitmap succeeded.
In cropBitmap, do not attempt to draw to a bitmap to an Index8
bitmap, which crashes. Use extractSubset instead.
Remove an assert.

R=djsollen@google.com

Review URL: https://codereview.chromium.org/14567011

git-svn-id: http://skia.googlecode.com/svn/trunk@8996 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
scroggo@google.com 2013-05-03 20:14:28 +00:00
parent dc9cdf8d49
commit 7e6fceeffd
6 changed files with 158 additions and 31 deletions

View File

@ -216,13 +216,21 @@ public:
bool buildTileIndex(SkStream*, int *width, int *height);
/**
* Decode a rectangle region in the image specified by rect.
* Decode a rectangle subset in the image.
* The method can only be called after buildTileIndex().
*
* Return true for success.
* Return false if the index is never built or failing in decoding.
*/
bool decodeRegion(SkBitmap* bitmap, const SkIRect& rect, SkBitmap::Config pref);
bool decodeSubset(SkBitmap* bm, const SkIRect& subset, SkBitmap::Config pref);
/**
* @Deprecated
* Use decodeSubset instead.
*/
bool decodeRegion(SkBitmap* bitmap, const SkIRect& rect, SkBitmap::Config pref) {
return this->decodeSubset(bitmap, rect, pref);
}
/** Given a stream, this will try to find an appropriate decoder object.
If none is found, the method returns NULL.
@ -344,7 +352,7 @@ protected:
// If the decoder wants to support tiled based decoding,
// this method must be overridden. This guy is called by decodeRegion(...)
virtual bool onDecodeRegion(SkBitmap* bitmap, const SkIRect& rect) {
virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) {
return false;
}
@ -359,10 +367,11 @@ protected:
* @param (dstX, dstY) the upper-left point of the dest bitmap in terms of
* the coordinate in the original bitmap.
* @param (width, height) the width and height of the unsampled dst.
* @param (srcX, srcY) the upper-left point of the src bitimap in terms of
* @param (srcX, srcY) the upper-left point of the src bitmap in terms of
* the coordinate in the original bitmap.
* @return bool Whether or not it succeeded.
*/
void cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
bool cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
int dstX, int dstY, int width, int height,
int srcX, int srcY);

View File

@ -33,9 +33,14 @@ void SkImageDecoder::SetDeviceConfig(SkBitmap::Config config)
///////////////////////////////////////////////////////////////////////////////
SkImageDecoder::SkImageDecoder()
: fPeeker(NULL), fChooser(NULL), fAllocator(NULL), fSampleSize(1),
fDefaultPref(SkBitmap::kNo_Config), fDitherImage(true),
fUsePrefTable(false),fPreferQualityOverSpeed(false) {
: fPeeker(NULL)
, fChooser(NULL)
, fAllocator(NULL)
, fSampleSize(1)
, fDefaultPref(SkBitmap::kNo_Config)
, fDitherImage(true)
, fUsePrefTable(false)
, fPreferQualityOverSpeed(false) {
}
SkImageDecoder::~SkImageDecoder() {
@ -177,14 +182,14 @@ bool SkImageDecoder::decode(SkStream* stream, SkBitmap* bm,
return true;
}
bool SkImageDecoder::decodeRegion(SkBitmap* bm, const SkIRect& rect,
bool SkImageDecoder::decodeSubset(SkBitmap* bm, const SkIRect& rect,
SkBitmap::Config pref) {
// we reset this to false before calling onDecodeRegion
// we reset this to false before calling onDecodeSubset
fShouldCancelDecode = false;
// assign this, for use by getPrefConfig(), in case fUsePrefTable is false
fDefaultPref = pref;
return this->onDecodeRegion(bm, rect);
return this->onDecodeSubset(bm, rect);
}
bool SkImageDecoder::buildTileIndex(SkStream* stream,
@ -195,11 +200,25 @@ bool SkImageDecoder::buildTileIndex(SkStream* stream,
return this->onBuildTileIndex(stream, width, height);
}
void SkImageDecoder::cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
bool SkImageDecoder::cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
int dstX, int dstY, int width, int height,
int srcX, int srcY) {
int w = width / sampleSize;
int h = height / sampleSize;
if (src->getConfig() == SkBitmap::kIndex8_Config) {
// kIndex8 does not allow drawing via an SkCanvas, as is done below.
// Instead, use extractSubset. Note that this shares the SkPixelRef and
// SkColorTable.
// FIXME: Since src is discarded in practice, this holds on to more
// pixels than is strictly necessary. Switch to a copy if memory
// savings are more important than speed here. This also means
// that the pixels in dst can not be reused (though there is no
// allocation, which was already done on src).
int x = (dstX - srcX) / sampleSize;
int y = (dstY - srcY) / sampleSize;
SkIRect subset = SkIRect::MakeXYWH(x, y, w, h);
return src->extractSubset(dst, subset);
}
// if the destination has no pixels then we must allocate them.
if (dst->isNull()) {
dst->setConfig(src->getConfig(), w, h);
@ -207,13 +226,15 @@ void SkImageDecoder::cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
if (!this->allocPixelRef(dst, NULL)) {
SkDEBUGF(("failed to allocate pixels needed to crop the bitmap"));
return;
return false;
}
}
// check to see if the destination is large enough to decode the desired
// region. If this assert fails we will just draw as much of the source
// into the destination that we can.
SkASSERT(dst->width() >= w && dst->height() >= h);
if (dst->width() < w || dst->height() < h) {
SkDEBUGF(("SkImageDecoder::cropBitmap does not have a large enough bitmap.\n"));
}
// Set the Src_Mode for the paint to prevent transparency issue in the
// dest in the event that the dest was being re-used.
@ -224,6 +245,7 @@ void SkImageDecoder::cropBitmap(SkBitmap *dst, SkBitmap *src, int sampleSize,
canvas.drawSprite(*src, (srcX - dstX) / sampleSize,
(srcY - dstY) / sampleSize,
&paint);
return true;
}
///////////////////////////////////////////////////////////////////////////////

View File

@ -118,7 +118,7 @@ public:
protected:
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
virtual bool onBuildTileIndex(SkStream *stream, int *width, int *height) SK_OVERRIDE;
virtual bool onDecodeRegion(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
#endif
virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
@ -556,7 +556,7 @@ bool SkJPEGImageDecoder::onBuildTileIndex(SkStream* stream, int *width, int *hei
return true;
}
bool SkJPEGImageDecoder::onDecodeRegion(SkBitmap* bm, const SkIRect& region) {
bool SkJPEGImageDecoder::onDecodeSubset(SkBitmap* bm, const SkIRect& region) {
if (NULL == fImageIndex) {
return false;
}

View File

@ -72,7 +72,7 @@ public:
protected:
#ifdef SK_BUILD_FOR_ANDROID
virtual bool onBuildTileIndex(SkStream *stream, int *width, int *height) SK_OVERRIDE;
virtual bool onDecodeRegion(SkBitmap* bitmap, const SkIRect& region) SK_OVERRIDE;
virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& region) SK_OVERRIDE;
#endif
virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
@ -642,7 +642,11 @@ bool SkPNGImageDecoder::onBuildTileIndex(SkStream* sk_stream, int *width, int *h
return true;
}
bool SkPNGImageDecoder::onDecodeRegion(SkBitmap* bm, const SkIRect& region) {
bool SkPNGImageDecoder::onDecodeSubset(SkBitmap* bm, const SkIRect& region) {
if (NULL == fImageIndex) {
return false;
}
png_structp png_ptr = fImageIndex->png_ptr;
png_infop info_ptr = fImageIndex->info_ptr;
if (setjmp(png_jmpbuf(png_ptr))) {
@ -657,7 +661,7 @@ bool SkPNGImageDecoder::onDecodeRegion(SkBitmap* bm, const SkIRect& region) {
SkIRect rect = SkIRect::MakeWH(origWidth, origHeight);
if (!rect.intersect(region)) {
// If the requested region is entirely outsides the image, just
// If the requested region is entirely outside the image, just
// returns false
return false;
}
@ -731,8 +735,8 @@ bool SkPNGImageDecoder::onDecodeRegion(SkBitmap* bm, const SkIRect& region) {
#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
png_ptr->pass = 0;
#else
// FIXME: Figure out what (if anything) to do when Android moves to
// libpng > 1.2.
// FIXME: This sets pass as desired, but also sets iwidth. Is that ok?
png_set_interlaced_pass(png_ptr, 0);
#endif
png_read_update_info(png_ptr, info_ptr);
@ -745,7 +749,8 @@ bool SkPNGImageDecoder::onDecodeRegion(SkBitmap* bm, const SkIRect& region) {
uint8_t* bmRow = decodedBitmap.getAddr8(0, 0);
png_read_rows(png_ptr, &bmRow, png_bytepp_NULL, 1);
}
for (png_uint_32 y = 0; y < origHeight; y++) {
png_uint_32 bitmapHeight = (png_uint_32) decodedBitmap.height();
for (png_uint_32 y = 0; y < bitmapHeight; y++) {
uint8_t* bmRow = decodedBitmap.getAddr8(0, y);
png_read_rows(png_ptr, &bmRow, png_bytepp_NULL, 1);
}
@ -826,12 +831,10 @@ bool SkPNGImageDecoder::onDecodeRegion(SkBitmap* bm, const SkIRect& region) {
if (swapOnly) {
bm->swap(decodedBitmap);
} else {
cropBitmap(bm, &decodedBitmap, sampleSize, region.x(), region.y(),
region.width(), region.height(), 0, rect.y());
}
return true;
}
return this->cropBitmap(bm, &decodedBitmap, sampleSize, region.x(), region.y(),
region.width(), region.height(), 0, rect.y());
}
#endif

View File

@ -111,7 +111,7 @@ public:
protected:
virtual bool onBuildTileIndex(SkStream *stream, int *width, int *height) SK_OVERRIDE;
virtual bool onDecodeRegion(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
private:
@ -321,7 +321,7 @@ static bool is_config_compatible(const SkBitmap& bitmap) {
config == SkBitmap::kARGB_8888_Config;
}
bool SkWEBPImageDecoder::onDecodeRegion(SkBitmap* decodedBitmap,
bool SkWEBPImageDecoder::onDecodeSubset(SkBitmap* decodedBitmap,
const SkIRect& region) {
SkIRect rect = SkIRect::MakeWH(fOrigWidth, fOrigHeight);

View File

@ -13,6 +13,7 @@
#include "SkImageDecoder.h"
#include "SkImageEncoder.h"
#include "SkOSFile.h"
#include "SkRandom.h"
#include "SkStream.h"
#include "SkTArray.h"
#include "SkTemplates.h"
@ -20,6 +21,7 @@
DEFINE_string2(readPath, r, "", "Folder(s) and files to decode images. Required.");
DEFINE_string2(writePath, w, "", "Write rendered images into this directory.");
DEFINE_bool(reencode, true, "Reencode the images to test encoding.");
DEFINE_bool(testSubsetDecoding, true, "Test decoding subsets of images.");
struct Format {
SkImageEncoder::Type fType;
@ -92,6 +94,8 @@ static SkTArray<SkString, false> gMissingCodecs;
static SkTArray<SkString, false> gDecodeFailures;
static SkTArray<SkString, false> gEncodeFailures;
static SkTArray<SkString, false> gSuccessfulDecodes;
static SkTArray<SkString, false> gSuccessfulSubsetDecodes;
static SkTArray<SkString, false> gFailedSubsetDecodes;
static bool write_bitmap(const char outName[], SkBitmap* bm) {
SkBitmap bitmap8888;
@ -112,6 +116,47 @@ static bool write_bitmap(const char outName[], SkBitmap* bm) {
return SkImageEncoder::EncodeFile(outName, *bm, SkImageEncoder::kPNG_Type, 100);
}
/**
* Return a random SkIRect inside the range specified.
* @param rand Random number generator.
* @param maxX Exclusive maximum x-coordinate. SkIRect's fLeft and fRight will be
* in the range [0, maxX)
* @param maxY Exclusive maximum y-coordinate. SkIRect's fTop and fBottom will be
* in the range [0, maxY)
* @return SkIRect Non-empty, non-degenerate rectangle.
*/
static SkIRect generate_random_rect(SkRandom* rand, int32_t maxX, int32_t maxY) {
SkASSERT(maxX > 1 && maxY > 1);
int32_t left = rand->nextULessThan(maxX);
int32_t right = rand->nextULessThan(maxX);
int32_t top = rand->nextULessThan(maxY);
int32_t bottom = rand->nextULessThan(maxY);
SkIRect rect = SkIRect::MakeLTRB(left, top, right, bottom);
rect.sort();
// Make sure rect is not empty.
if (rect.fLeft == rect.fRight) {
if (rect.fLeft > 0) {
rect.fLeft--;
} else {
rect.fRight++;
// This branch is only taken if 0 == rect.fRight, and
// maxX must be at least 2, so it must still be in
// range.
SkASSERT(rect.fRight < maxX);
}
}
if (rect.fTop == rect.fBottom) {
if (rect.fTop > 0) {
rect.fTop--;
} else {
rect.fBottom++;
// Again, this must be in range.
SkASSERT(rect.fBottom < maxY);
}
}
return rect;
}
static void decodeFileAndWrite(const char srcPath[], const SkString* writePath) {
SkBitmap bitmap;
SkFILEStream stream(srcPath);
@ -137,6 +182,49 @@ static void decodeFileAndWrite(const char srcPath[], const SkString* writePath)
gSuccessfulDecodes.push_back().printf("%s [%d %d]", srcPath, bitmap.width(), bitmap.height());
if (FLAGS_testSubsetDecoding) {
bool couldRewind = stream.rewind();
SkASSERT(couldRewind);
int width, height;
// Build the tile index for decoding subsets. If the image is 1x1, skip subset
// decoding since there are no smaller subsets.
if (codec->buildTileIndex(&stream, &width, &height) && width > 1 && height > 1) {
SkASSERT(bitmap.width() == width && bitmap.height() == height);
// Call decodeSubset multiple times:
SkRandom rand(0);
for (int i = 0; i < 5; i++) {
SkBitmap bitmapFromDecodeSubset;
// FIXME: Come up with a more representative set of rectangles.
SkIRect rect = generate_random_rect(&rand, width, height);
SkString subsetDim = SkStringPrintf("[%d,%d,%d,%d]", rect.fLeft, rect.fTop,
rect.fRight, rect.fBottom);
if (codec->decodeSubset(&bitmapFromDecodeSubset, rect, SkBitmap::kNo_Config)) {
gSuccessfulSubsetDecodes.push_back().printf("Decoded subset %s from %s",
subsetDim.c_str(), srcPath);
if (writePath != NULL) {
// Write the region to a file whose name includes the dimensions.
SkString suffix = SkStringPrintf("_%s.png", subsetDim.c_str());
SkString outPath;
make_outname(&outPath, writePath->c_str(), srcPath, suffix.c_str());
bool success = write_bitmap(outPath.c_str(), &bitmapFromDecodeSubset);
SkASSERT(success);
gSuccessfulSubsetDecodes.push_back().printf("\twrote %s", outPath.c_str());
// Also use extractSubset from the original for visual comparison.
SkBitmap extractedSubset;
if (bitmap.extractSubset(&extractedSubset, rect)) {
suffix.printf("_%s_extracted.png", subsetDim.c_str());
make_outname(&outPath, writePath->c_str(), srcPath, suffix.c_str());
success = write_bitmap(outPath.c_str(), &extractedSubset);
SkASSERT(success);
}
}
} else {
gFailedSubsetDecodes.push_back().printf("Failed to decode region %s from %s\n",
subsetDim.c_str(), srcPath);
}
}
}
}
if (FLAGS_reencode) {
// Encode to the format the file was originally in, or PNG if the encoder for the same
// format is unavailable.
@ -289,6 +377,11 @@ int tool_main(int argc, char** argv) {
failed |= print_strings("Failed to encode", gEncodeFailures);
print_strings("Decoded", gSuccessfulDecodes);
if (FLAGS_testSubsetDecoding) {
failed |= print_strings("Failed subset decodes", gFailedSubsetDecodes);
print_strings("Decoded subsets", gSuccessfulSubsetDecodes);
}
return failed ? -1 : 0;
}