| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkPDFBitmap.h" |
| |
| #include "SkColorData.h" |
| #include "SkData.h" |
| #include "SkDeflate.h" |
| #include "SkImage.h" |
| #include "SkJpegInfo.h" |
| #include "SkPDFCanon.h" |
| #include "SkPDFTypes.h" |
| #include "SkPDFUtils.h" |
| #include "SkStream.h" |
| #include "SkUnPreMultiply.h" |
| |
| bool image_compute_is_opaque(const SkImage* image) { |
| if (image->isOpaque()) { |
| return true; |
| } |
| // keep output PDF small at cost of possible resource use. |
| SkBitmap bm; |
| // if image can not be read, treat as transparent. |
| return SkPDFUtils::ToBitmap(image, &bm) && SkBitmap::ComputeIsOpaque(bm); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| static const char kStreamBegin[] = " stream\n"; |
| |
| static const char kStreamEnd[] = "\nendstream"; |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| // write a single byte to a stream n times. |
| static void fill_stream(SkWStream* out, char value, size_t n) { |
| char buffer[4096]; |
| memset(buffer, value, sizeof(buffer)); |
| for (size_t i = 0; i < n / sizeof(buffer); ++i) { |
| out->write(buffer, sizeof(buffer)); |
| } |
| out->write(buffer, n % sizeof(buffer)); |
| } |
| |
| // TODO(reed@): Decide if these five functions belong in SkColorData.h |
| static bool SkIsBGRA(SkColorType ct) { |
| SkASSERT(kBGRA_8888_SkColorType == ct || kRGBA_8888_SkColorType == ct); |
| return kBGRA_8888_SkColorType == ct; |
| } |
| |
| // Interpret value as the given 4-byte SkColorType (BGRA_8888 or |
| // RGBA_8888) and return the appropriate component. Each component |
| // should be interpreted according to the associated SkAlphaType and |
| // SkColorProfileType. |
| static U8CPU SkGetA32Component(uint32_t value, SkColorType ct) { |
| return (value >> (SkIsBGRA(ct) ? SK_BGRA_A32_SHIFT : SK_RGBA_A32_SHIFT)) & 0xFF; |
| } |
| static U8CPU SkGetR32Component(uint32_t value, SkColorType ct) { |
| return (value >> (SkIsBGRA(ct) ? SK_BGRA_R32_SHIFT : SK_RGBA_R32_SHIFT)) & 0xFF; |
| } |
| static U8CPU SkGetG32Component(uint32_t value, SkColorType ct) { |
| return (value >> (SkIsBGRA(ct) ? SK_BGRA_G32_SHIFT : SK_RGBA_G32_SHIFT)) & 0xFF; |
| } |
| static U8CPU SkGetB32Component(uint32_t value, SkColorType ct) { |
| return (value >> (SkIsBGRA(ct) ? SK_BGRA_B32_SHIFT : SK_RGBA_B32_SHIFT)) & 0xFF; |
| } |
| |
| // unpremultiply and extract R, G, B components. |
| static void pmcolor_to_rgb24(uint32_t color, uint8_t* rgb, SkColorType ct) { |
| SkPMColorAssert(color); |
| uint32_t s = SkUnPreMultiply::GetScale(SkGetA32Component(color, ct)); |
| rgb[0] = SkUnPreMultiply::ApplyScale(s, SkGetR32Component(color, ct)); |
| rgb[1] = SkUnPreMultiply::ApplyScale(s, SkGetG32Component(color, ct)); |
| rgb[2] = SkUnPreMultiply::ApplyScale(s, SkGetB32Component(color, ct)); |
| } |
| |
| /* It is necessary to average the color component of transparent |
| pixels with their surrounding neighbors since the PDF renderer may |
| separately re-sample the alpha and color channels when the image is |
| not displayed at its native resolution. Since an alpha of zero |
| gives no information about the color component, the pathological |
| case is a white image with sharp transparency bounds - the color |
| channel goes to black, and the should-be-transparent pixels are |
| rendered as grey because of the separate soft mask and color |
| resizing. e.g.: gm/bitmappremul.cpp */ |
| static void get_neighbor_avg_color(const SkBitmap& bm, |
| int xOrig, |
| int yOrig, |
| uint8_t rgb[3], |
| SkColorType ct) { |
| unsigned a = 0, r = 0, g = 0, b = 0; |
| // Clamp the range to the edge of the bitmap. |
| int ymin = SkTMax(0, yOrig - 1); |
| int ymax = SkTMin(yOrig + 1, bm.height() - 1); |
| int xmin = SkTMax(0, xOrig - 1); |
| int xmax = SkTMin(xOrig + 1, bm.width() - 1); |
| for (int y = ymin; y <= ymax; ++y) { |
| uint32_t* scanline = bm.getAddr32(0, y); |
| for (int x = xmin; x <= xmax; ++x) { |
| uint32_t color = scanline[x]; |
| SkPMColorAssert(color); |
| a += SkGetA32Component(color, ct); |
| r += SkGetR32Component(color, ct); |
| g += SkGetG32Component(color, ct); |
| b += SkGetB32Component(color, ct); |
| } |
| } |
| if (a > 0) { |
| rgb[0] = SkToU8(255 * r / a); |
| rgb[1] = SkToU8(255 * g / a); |
| rgb[2] = SkToU8(255 * b / a); |
| } else { |
| rgb[0] = rgb[1] = rgb[2] = 0; |
| } |
| } |
| |
| static size_t pixel_count(const SkBitmap& bm) { |
| return SkToSizeT(bm.width()) * SkToSizeT(bm.height()); |
| } |
| |
| static const SkBitmap& supported_colortype(const SkBitmap& input, SkBitmap* copy) { |
| switch (input.colorType()) { |
| case kUnknown_SkColorType: |
| SkDEBUGFAIL("kUnknown_SkColorType"); |
| case kAlpha_8_SkColorType: |
| case kRGB_565_SkColorType: |
| case kRGBA_8888_SkColorType: |
| case kBGRA_8888_SkColorType: |
| case kGray_8_SkColorType: |
| return input; // supported |
| default: |
| // if other colortypes are introduced in the future, |
| // they will hit this code. |
| break; |
| } |
| // Fallback for rarely used ARGB_4444 and ARGB_F16: do a wasteful tmp copy. |
| copy->allocPixels(input.info().makeColorType(kN32_SkColorType)); |
| SkAssertResult(input.readPixels(copy->info(), copy->getPixels(), copy->rowBytes(), 0, 0)); |
| copy->setImmutable(); |
| return *copy; |
| } |
| |
| static size_t pdf_color_component_count(SkColorType ct) { |
| switch (ct) { |
| case kUnknown_SkColorType: |
| SkDEBUGFAIL("kUnknown_SkColorType"); |
| case kAlpha_8_SkColorType: |
| case kGray_8_SkColorType: |
| return 1; |
| case kRGB_565_SkColorType: |
| case kRGBA_8888_SkColorType: |
| case kBGRA_8888_SkColorType: |
| default: // converted to N32 |
| return 3; |
| } |
| } |
| |
| static void bitmap_to_pdf_pixels(const SkBitmap& bitmap, SkWStream* out) { |
| if (!bitmap.getPixels()) { |
| size_t size = pixel_count(bitmap) * |
| pdf_color_component_count(bitmap.colorType()); |
| fill_stream(out, '\x00', size); |
| return; |
| } |
| SkBitmap copy; |
| const SkBitmap& bm = supported_colortype(bitmap, ©); |
| SkColorType colorType = bm.colorType(); |
| SkAlphaType alphaType = bm.alphaType(); |
| switch (colorType) { |
| case kRGBA_8888_SkColorType: |
| case kBGRA_8888_SkColorType: { |
| SkASSERT(3 == pdf_color_component_count(colorType)); |
| SkAutoTMalloc<uint8_t> scanline(3 * bm.width()); |
| for (int y = 0; y < bm.height(); ++y) { |
| const uint32_t* src = bm.getAddr32(0, y); |
| uint8_t* dst = scanline.get(); |
| for (int x = 0; x < bm.width(); ++x) { |
| if (alphaType == kPremul_SkAlphaType) { |
| uint32_t color = *src++; |
| U8CPU alpha = SkGetA32Component(color, colorType); |
| if (alpha != SK_AlphaTRANSPARENT) { |
| pmcolor_to_rgb24(color, dst, colorType); |
| } else { |
| get_neighbor_avg_color(bm, x, y, dst, colorType); |
| } |
| dst += 3; |
| } else { |
| uint32_t color = *src++; |
| *dst++ = SkGetR32Component(color, colorType); |
| *dst++ = SkGetG32Component(color, colorType); |
| *dst++ = SkGetB32Component(color, colorType); |
| } |
| } |
| out->write(scanline.get(), 3 * bm.width()); |
| } |
| return; |
| } |
| case kRGB_565_SkColorType: { |
| SkASSERT(3 == pdf_color_component_count(colorType)); |
| SkAutoTMalloc<uint8_t> scanline(3 * bm.width()); |
| for (int y = 0; y < bm.height(); ++y) { |
| const uint16_t* src = bm.getAddr16(0, y); |
| uint8_t* dst = scanline.get(); |
| for (int x = 0; x < bm.width(); ++x) { |
| U16CPU color565 = *src++; |
| *dst++ = SkPacked16ToR32(color565); |
| *dst++ = SkPacked16ToG32(color565); |
| *dst++ = SkPacked16ToB32(color565); |
| } |
| out->write(scanline.get(), 3 * bm.width()); |
| } |
| return; |
| } |
| case kAlpha_8_SkColorType: |
| SkASSERT(1 == pdf_color_component_count(colorType)); |
| fill_stream(out, '\x00', pixel_count(bm)); |
| return; |
| case kGray_8_SkColorType: |
| SkASSERT(1 == pdf_color_component_count(colorType)); |
| // these two formats need no transformation to serialize. |
| for (int y = 0; y < bm.height(); ++y) { |
| out->write(bm.getAddr8(0, y), bm.width()); |
| } |
| return; |
| case kUnknown_SkColorType: |
| case kARGB_4444_SkColorType: |
| default: |
| SkDEBUGFAIL("unexpected color type"); |
| } |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| static void bitmap_alpha_to_a8(const SkBitmap& bitmap, SkWStream* out) { |
| if (!bitmap.getPixels()) { |
| fill_stream(out, '\xFF', pixel_count(bitmap)); |
| return; |
| } |
| SkBitmap copy; |
| const SkBitmap& bm = supported_colortype(bitmap, ©); |
| SkColorType colorType = bm.colorType(); |
| switch (colorType) { |
| case kRGBA_8888_SkColorType: |
| case kBGRA_8888_SkColorType: { |
| SkAutoTMalloc<uint8_t> scanline(bm.width()); |
| for (int y = 0; y < bm.height(); ++y) { |
| uint8_t* dst = scanline.get(); |
| const SkPMColor* src = bm.getAddr32(0, y); |
| for (int x = 0; x < bm.width(); ++x) { |
| *dst++ = SkGetA32Component(*src++, colorType); |
| } |
| out->write(scanline.get(), bm.width()); |
| } |
| return; |
| } |
| case kAlpha_8_SkColorType: |
| for (int y = 0; y < bm.height(); ++y) { |
| out->write(bm.getAddr8(0, y), bm.width()); |
| } |
| return; |
| case kRGB_565_SkColorType: |
| case kGray_8_SkColorType: |
| SkDEBUGFAIL("color type has no alpha"); |
| return; |
| case kARGB_4444_SkColorType: |
| SkDEBUGFAIL("4444 color type should have been converted to N32"); |
| return; |
| case kUnknown_SkColorType: |
| default: |
| SkDEBUGFAIL("unexpected color type"); |
| } |
| } |
| |
| static void emit_image_xobject(SkWStream* stream, |
| const SkImage* image, |
| bool alpha, |
| const sk_sp<SkPDFObject>& smask, |
| const SkPDFObjNumMap& objNumMap) { |
| SkBitmap bitmap; |
| if (!SkPDFUtils::ToBitmap(image, &bitmap)) { |
| // no pixels or wrong size: fill with zeros. |
| bitmap.setInfo(SkImageInfo::MakeN32(image->width(), image->height(), image->alphaType())); |
| } |
| |
| // Write to a temporary buffer to get the compressed length. |
| SkDynamicMemoryWStream buffer; |
| SkDeflateWStream deflateWStream(&buffer); |
| if (alpha) { |
| bitmap_alpha_to_a8(bitmap, &deflateWStream); |
| } else { |
| bitmap_to_pdf_pixels(bitmap, &deflateWStream); |
| } |
| deflateWStream.finalize(); // call before buffer.bytesWritten(). |
| |
| SkPDFDict pdfDict("XObject"); |
| pdfDict.insertName("Subtype", "Image"); |
| pdfDict.insertInt("Width", bitmap.width()); |
| pdfDict.insertInt("Height", bitmap.height()); |
| if (alpha) { |
| pdfDict.insertName("ColorSpace", "DeviceGray"); |
| } else if (1 == pdf_color_component_count(bitmap.colorType())) { |
| pdfDict.insertName("ColorSpace", "DeviceGray"); |
| } else { |
| pdfDict.insertName("ColorSpace", "DeviceRGB"); |
| } |
| if (smask) { |
| pdfDict.insertObjRef("SMask", smask); |
| } |
| pdfDict.insertInt("BitsPerComponent", 8); |
| pdfDict.insertName("Filter", "FlateDecode"); |
| pdfDict.insertInt("Length", buffer.bytesWritten()); |
| pdfDict.emitObject(stream, objNumMap); |
| |
| stream->writeText(kStreamBegin); |
| buffer.writeToAndReset(stream); |
| stream->writeText(kStreamEnd); |
| } |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| namespace { |
| // This SkPDFObject only outputs the alpha layer of the given bitmap. |
| class PDFAlphaBitmap final : public SkPDFObject { |
| public: |
| PDFAlphaBitmap(sk_sp<SkImage> image) : fImage(std::move(image)) { SkASSERT(fImage); } |
| void emitObject(SkWStream* stream, |
| const SkPDFObjNumMap& objNumMap) const override { |
| SkASSERT(fImage); |
| emit_image_xobject(stream, fImage.get(), true, nullptr, objNumMap); |
| } |
| void drop() override { fImage = nullptr; } |
| |
| private: |
| sk_sp<SkImage> fImage; |
| }; |
| |
| } // namespace |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| namespace { |
| class PDFDefaultBitmap final : public SkPDFObject { |
| public: |
| void emitObject(SkWStream* stream, |
| const SkPDFObjNumMap& objNumMap) const override { |
| SkASSERT(fImage); |
| emit_image_xobject(stream, fImage.get(), false, fSMask, objNumMap); |
| } |
| void addResources(SkPDFObjNumMap* catalog) const override { |
| catalog->addObjectRecursively(fSMask.get()); |
| } |
| void drop() override { fImage = nullptr; fSMask = nullptr; } |
| PDFDefaultBitmap(sk_sp<SkImage> image, sk_sp<SkPDFObject> smask) |
| : fImage(std::move(image)), fSMask(std::move(smask)) { SkASSERT(fImage); } |
| |
| private: |
| sk_sp<SkImage> fImage; |
| sk_sp<SkPDFObject> fSMask; |
| }; |
| } // namespace |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| namespace { |
| /** |
| * This PDFObject assumes that its constructor was handed YUV or |
| * Grayscale JFIF Jpeg-encoded data that can be directly embedded |
| * into a PDF. |
| */ |
| class PDFJpegBitmap final : public SkPDFObject { |
| public: |
| SkISize fSize; |
| sk_sp<SkData> fData; |
| bool fIsYUV; |
| PDFJpegBitmap(SkISize size, sk_sp<SkData> data, bool isYUV) |
| : fSize(size), fData(std::move(data)), fIsYUV(isYUV) { SkASSERT(fData); } |
| void emitObject(SkWStream*, const SkPDFObjNumMap&) const override; |
| void drop() override { fData = nullptr; } |
| }; |
| |
| void PDFJpegBitmap::emitObject(SkWStream* stream, |
| const SkPDFObjNumMap& objNumMap) const { |
| SkASSERT(fData); |
| SkPDFDict pdfDict("XObject"); |
| pdfDict.insertName("Subtype", "Image"); |
| pdfDict.insertInt("Width", fSize.width()); |
| pdfDict.insertInt("Height", fSize.height()); |
| if (fIsYUV) { |
| pdfDict.insertName("ColorSpace", "DeviceRGB"); |
| } else { |
| pdfDict.insertName("ColorSpace", "DeviceGray"); |
| } |
| pdfDict.insertInt("BitsPerComponent", 8); |
| pdfDict.insertName("Filter", "DCTDecode"); |
| pdfDict.insertInt("ColorTransform", 0); |
| pdfDict.insertInt("Length", SkToInt(fData->size())); |
| pdfDict.emitObject(stream, objNumMap); |
| stream->writeText(kStreamBegin); |
| stream->write(fData->data(), fData->size()); |
| stream->writeText(kStreamEnd); |
| } |
| } // namespace |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| sk_sp<PDFJpegBitmap> make_jpeg_bitmap(sk_sp<SkData> data, SkISize size) { |
| SkISize jpegSize; |
| SkEncodedInfo::Color jpegColorType; |
| SkEncodedOrigin exifOrientation; |
| if (data && SkGetJpegInfo(data->data(), data->size(), &jpegSize, |
| &jpegColorType, &exifOrientation)) { |
| bool yuv = jpegColorType == SkEncodedInfo::kYUV_Color; |
| bool goodColorType = yuv || jpegColorType == SkEncodedInfo::kGray_Color; |
| if (jpegSize == size // Sanity check. |
| && goodColorType |
| && kTopLeft_SkEncodedOrigin == exifOrientation) { |
| // hold on to data, not image. |
| #ifdef SK_PDF_IMAGE_STATS |
| gJpegImageObjects.fetch_add(1); |
| #endif |
| return sk_make_sp<PDFJpegBitmap>(jpegSize, std::move(data), yuv); |
| } |
| } |
| return nullptr; |
| } |
| |
| sk_sp<SkPDFObject> SkPDFCreateBitmapObject(sk_sp<SkImage> image, int encodingQuality) { |
| SkASSERT(image); |
| SkASSERT(encodingQuality >= 0); |
| SkISize dimensions = image->dimensions(); |
| sk_sp<SkData> data = image->refEncodedData(); |
| if (auto jpeg = make_jpeg_bitmap(std::move(data), dimensions)) { |
| return std::move(jpeg); |
| } |
| |
| const bool isOpaque = image_compute_is_opaque(image.get()); |
| |
| if (encodingQuality <= 100 && isOpaque) { |
| data = image->encodeToData(SkEncodedImageFormat::kJPEG, encodingQuality); |
| if (auto jpeg = make_jpeg_bitmap(std::move(data), dimensions)) { |
| return std::move(jpeg); |
| } |
| } |
| |
| sk_sp<SkPDFObject> smask; |
| if (!isOpaque) { |
| smask = sk_make_sp<PDFAlphaBitmap>(image); |
| } |
| #ifdef SK_PDF_IMAGE_STATS |
| gRegularImageObjects.fetch_add(1); |
| #endif |
| return sk_make_sp<PDFDefaultBitmap>(std::move(image), std::move(smask)); |
| } |