Revert of PDF: remove last use of SkPDFImage

src/pdf/SkPDFImage.cpp

+/*
+ * Copyright 2010 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 "SkPDFImage.h"
+
+#include "SkBitmap.h"
+#include "SkColor.h"
+#include "SkColorPriv.h"
+#include "SkData.h"
+#include "SkFlate.h"
+#include "SkPDFBitmap.h"
+#include "SkPDFCatalog.h"
+#include "SkPixelRef.h"
+#include "SkRect.h"
+#include "SkStream.h"
+#include "SkString.h"
+#include "SkUnPreMultiply.h"
+
+static size_t get_uncompressed_size(const SkBitmap& bitmap,
+                                    const SkIRect& srcRect) {
+    switch (bitmap.colorType()) {
+        case kIndex_8_SkColorType:
+            return srcRect.width() * srcRect.height();
+        case kARGB_4444_SkColorType:
+            return ((srcRect.width() * 3 + 1) / 2) * srcRect.height();
+        case kRGB_565_SkColorType:
+            return srcRect.width() * 3 * srcRect.height();
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
+        case kGray_8_SkColorType:
+            return srcRect.width() * 3 * srcRect.height();
+        case kAlpha_8_SkColorType:
+            return 1;
+        default:
+            SkASSERT(false);
+            return 0;
+    }
+}
+
+static SkStream* extract_index8_image(const SkBitmap& bitmap,
+                                      const SkIRect& srcRect) {
+    const int rowBytes = srcRect.width();
+    SkStream* stream = SkNEW_ARGS(SkMemoryStream,
+                                  (get_uncompressed_size(bitmap, srcRect)));
+    uint8_t* dst = (uint8_t*)stream->getMemoryBase();
+
+    for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+        memcpy(dst, bitmap.getAddr8(srcRect.fLeft, y), rowBytes);
+        dst += rowBytes;
+    }
+    return stream;
+}
+
+static SkStream* extract_argb4444_data(const SkBitmap& bitmap,
+                                       const SkIRect& srcRect,
+                                       bool extractAlpha,
+                                       bool* isOpaque,
+                                       bool* isTransparent) {
+    SkStream* stream;
+    uint8_t* dst = NULL;
+    if (extractAlpha) {
+        const int alphaRowBytes = (srcRect.width() + 1) / 2;
+        stream = SkNEW_ARGS(SkMemoryStream,
+                            (alphaRowBytes * srcRect.height()));
+    } else {
+        stream = SkNEW_ARGS(SkMemoryStream,
+                            (get_uncompressed_size(bitmap, srcRect)));
+    }
+    dst = (uint8_t*)stream->getMemoryBase();
+
+    for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+        uint16_t* src = bitmap.getAddr16(0, y);
+        int x;
+        for (x = srcRect.fLeft; x + 1 < srcRect.fRight; x += 2) {
+            if (extractAlpha) {
+                dst[0] = (SkGetPackedA4444(src[x]) << 4) |
+                    SkGetPackedA4444(src[x + 1]);
+                *isOpaque &= dst[0] == SK_AlphaOPAQUE;
+                *isTransparent &= dst[0] == SK_AlphaTRANSPARENT;
+                dst++;
+            } else {
+                dst[0] = (SkGetPackedR4444(src[x]) << 4) |
+                    SkGetPackedG4444(src[x]);
+                dst[1] = (SkGetPackedB4444(src[x]) << 4) |
+                    SkGetPackedR4444(src[x + 1]);
+                dst[2] = (SkGetPackedG4444(src[x + 1]) << 4) |
+                    SkGetPackedB4444(src[x + 1]);
+                dst += 3;
+            }
+        }
+        if (srcRect.width() & 1) {
+            if (extractAlpha) {
+                dst[0] = (SkGetPackedA4444(src[x]) << 4);
+                *isOpaque &= dst[0] == (SK_AlphaOPAQUE & 0xF0);
+                *isTransparent &= dst[0] == (SK_AlphaTRANSPARENT & 0xF0);
+                dst++;
+
+            } else {
+                dst[0] = (SkGetPackedR4444(src[x]) << 4) |
+                    SkGetPackedG4444(src[x]);
+                dst[1] = (SkGetPackedB4444(src[x]) << 4);
+                dst += 2;
+            }
+        }
+    }
+    return stream;
+}
+
+static SkStream* extract_rgb565_image(const SkBitmap& bitmap,
+                                      const SkIRect& srcRect) {
+    SkStream* stream = SkNEW_ARGS(SkMemoryStream,
+                                  (get_uncompressed_size(bitmap,
+                                                         srcRect)));
+    uint8_t* dst = (uint8_t*)stream->getMemoryBase();
+    for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+        uint16_t* src = bitmap.getAddr16(0, y);
+        for (int x = srcRect.fLeft; x < srcRect.fRight; x++) {
+            dst[0] = SkGetPackedR16(src[x]);
+            dst[1] = SkGetPackedG16(src[x]);
+            dst[2] = SkGetPackedB16(src[x]);
+            dst += 3;
+        }
+    }
+    return stream;
+}
+
+static SkStream* extract_gray8_image(const SkBitmap& bitmap, const SkIRect& srcRect) {
+    SkStream* stream = SkNEW_ARGS(SkMemoryStream,
+                                  (get_uncompressed_size(bitmap, srcRect)));
+    uint8_t* dst = (uint8_t*)stream->getMemoryBase();
+    for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+        uint8_t* src = bitmap.getAddr8(0, y);
+        for (int x = srcRect.fLeft; x < srcRect.fRight; x++) {
+            dst[0] = dst[1] = dst[2] = src[x];
+            dst += 3;
+        }
+    }
+    return stream;
+}
+
+static uint32_t get_argb8888_neighbor_avg_color(const SkBitmap& bitmap,
+                                                int xOrig,
+                                                int yOrig);
+
+static SkStream* extract_argb8888_data(const SkBitmap& bitmap,
+                                       const SkIRect& srcRect,
+                                       bool extractAlpha,
+                                       bool* isOpaque,
+                                       bool* isTransparent) {
+    size_t streamSize = extractAlpha ? srcRect.width() * srcRect.height()
+                                     : get_uncompressed_size(bitmap, srcRect);
+    SkStream* stream = SkNEW_ARGS(SkMemoryStream, (streamSize));
+    uint8_t* dst = (uint8_t*)stream->getMemoryBase();
+
+    const SkUnPreMultiply::Scale* scaleTable = SkUnPreMultiply::GetScaleTable();
+
+    for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+        uint32_t* src = bitmap.getAddr32(0, y);
+        for (int x = srcRect.fLeft; x < srcRect.fRight; x++) {
+            SkPMColor c = src[x];
+            U8CPU alpha = SkGetPackedA32(c);
+            if (extractAlpha) {
+                *isOpaque &= alpha == SK_AlphaOPAQUE;
+                *isTransparent &= alpha == SK_AlphaTRANSPARENT;
+                *dst++ = alpha;
+            } else {
+                if (SK_AlphaTRANSPARENT == alpha) {
+                    // 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.
+                    c = get_argb8888_neighbor_avg_color(bitmap, x, y);
+                    *dst++ = SkGetPackedR32(c);
+                    *dst++ = SkGetPackedG32(c);
+                    *dst++ = SkGetPackedB32(c);
+                } else {
+                    SkUnPreMultiply::Scale s = scaleTable[alpha];
+                    *dst++ = SkUnPreMultiply::ApplyScale(s, SkGetPackedR32(c));
+                    *dst++ = SkUnPreMultiply::ApplyScale(s, SkGetPackedG32(c));
+                    *dst++ = SkUnPreMultiply::ApplyScale(s, SkGetPackedB32(c));
+                }
+            }
+        }
+    }
+    SkASSERT(dst == streamSize + (uint8_t*)stream->getMemoryBase());
+    return stream;
+}
+
+static SkStream* extract_a8_alpha(const SkBitmap& bitmap,
+                                  const SkIRect& srcRect,
+                                  bool* isOpaque,
+                                  bool* isTransparent) {
+    const int alphaRowBytes = srcRect.width();
+    SkStream* stream = SkNEW_ARGS(SkMemoryStream,
+                                  (alphaRowBytes * srcRect.height()));
+    uint8_t* alphaDst = (uint8_t*)stream->getMemoryBase();
+
+    for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+        uint8_t* src = bitmap.getAddr8(0, y);
+        for (int x = srcRect.fLeft; x < srcRect.fRight; x++) {
+            alphaDst[0] = src[x];
+            *isOpaque &= alphaDst[0] == SK_AlphaOPAQUE;
+            *isTransparent &= alphaDst[0] == SK_AlphaTRANSPARENT;
+            alphaDst++;
+        }
+    }
+    return stream;
+}
+
+static SkStream* create_black_image() {
+    SkStream* stream = SkNEW_ARGS(SkMemoryStream, (1));
+    ((uint8_t*)stream->getMemoryBase())[0] = 0;
+    return stream;
+}
+
+/**
+ * Extract either the color or image data from a SkBitmap into a SkStream.
+ * @param bitmap        Bitmap to extract data from.
+ * @param srcRect       Region in the bitmap to extract.
+ * @param extractAlpha  Set to true to extract the alpha data or false to
+ *                      extract the color data.
+ * @param isTransparent Pointer to a bool to output whether the alpha is
+ *                      completely transparent. May be NULL. Only valid when
+ *                      extractAlpha == true.
+ * @return              Unencoded image data, or NULL if either data was not
+ *                      available or alpha data was requested but the image was
+ *                      entirely transparent or opaque.
+ */
+static SkStream* extract_image_data(const SkBitmap& bitmap,
+                                    const SkIRect& srcRect,
+                                    bool extractAlpha, bool* isTransparent) {
+    SkColorType colorType = bitmap.colorType();
+    if (extractAlpha && (kIndex_8_SkColorType == colorType ||
+                         kRGB_565_SkColorType == colorType ||
+                         kGray_8_SkColorType  == colorType)) {
+        if (isTransparent != NULL) {
+            *isTransparent = false;
+        }
+        return NULL;
+    }
+
+    SkAutoLockPixels lock(bitmap);
+    if (NULL == bitmap.getPixels()) {
+        return NULL;
+    }
+
+    bool isOpaque = true;
+    bool transparent = extractAlpha;
+    SkAutoTDelete<SkStream> stream;
+
+    switch (colorType) {
+        case kIndex_8_SkColorType:
+            if (!extractAlpha) {
+                stream.reset(extract_index8_image(bitmap, srcRect));
+            }
+            break;
+        case kARGB_4444_SkColorType:
+            stream.reset(extract_argb4444_data(bitmap, srcRect, extractAlpha,
+                                               &isOpaque, &transparent));
+            break;
+        case kRGB_565_SkColorType:
+            if (!extractAlpha) {
+                stream.reset(extract_rgb565_image(bitmap, srcRect));
+            }
+            break;
+        case kGray_8_SkColorType:
+            if (!extractAlpha) {
+                stream.reset(extract_gray8_image(bitmap, srcRect));
+            }
+            break;
+        case kN32_SkColorType:
+            stream.reset(extract_argb8888_data(bitmap, srcRect, extractAlpha,
+                                               &isOpaque, &transparent));
+            break;
+        case kAlpha_8_SkColorType:
+            if (!extractAlpha) {
+                stream.reset(create_black_image());
+            } else {
+                stream.reset(extract_a8_alpha(bitmap, srcRect,
+                                              &isOpaque, &transparent));
+            }
+            break;
+        default:
+            SkASSERT(false);
+    }
+
+    if (isTransparent != NULL) {
+        *isTransparent = transparent;
+    }
+    if (extractAlpha && (transparent || isOpaque)) {
+        return NULL;
+    }
+    return stream.detach();
+}
+
+static SkPDFArray* make_indexed_color_space(SkColorTable* table) {
+    SkPDFArray* result = new SkPDFArray();
+    result->reserve(4);
+    result->appendName("Indexed");
+    result->appendName("DeviceRGB");
+    result->appendInt(table->count() - 1);
+
+    // Potentially, this could be represented in fewer bytes with a stream.
+    // Max size as a string is 1.5k.
+    SkString index;
+    for (int i = 0; i < table->count(); i++) {
+        char buf[3];
+        SkColor color = SkUnPreMultiply::PMColorToColor((*table)[i]);
+        buf[0] = SkGetPackedR32(color);
+        buf[1] = SkGetPackedG32(color);
+        buf[2] = SkGetPackedB32(color);
+        index.append(buf, 3);
+    }
+    result->append(new SkPDFString(index))->unref();
+    return result;
+}
+
+/**
+ * Removes the alpha component of an ARGB color (including unpremultiply) while
+ * keeping the output in the same format as the input.
+ */
+static uint32_t remove_alpha_argb8888(uint32_t pmColor) {
+    SkColor color = SkUnPreMultiply::PMColorToColor(pmColor);
+    return SkPackARGB32NoCheck(SK_AlphaOPAQUE,
+                               SkColorGetR(color),
+                               SkColorGetG(color),
+                               SkColorGetB(color));
+}
+
+static uint16_t remove_alpha_argb4444(uint16_t pmColor) {
+    return SkPixel32ToPixel4444(
+            remove_alpha_argb8888(SkPixel4444ToPixel32(pmColor)));
+}
+
+static uint32_t get_argb8888_neighbor_avg_color(const SkBitmap& bitmap,
+                                                int xOrig, int yOrig) {
+    uint8_t count = 0;
+    uint16_t r = 0;
+    uint16_t g = 0;
+    uint16_t b = 0;
+
+    for (int y = yOrig - 1; y <= yOrig + 1; y++) {
+        if (y < 0 || y >= bitmap.height()) {
+            continue;
+        }
+        uint32_t* src = bitmap.getAddr32(0, y);
+        for (int x = xOrig - 1; x <= xOrig + 1; x++) {
+            if (x < 0 || x >= bitmap.width()) {
+                continue;
+            }
+            if (SkGetPackedA32(src[x]) != SK_AlphaTRANSPARENT) {
+                uint32_t color = remove_alpha_argb8888(src[x]);
+                r += SkGetPackedR32(color);
+                g += SkGetPackedG32(color);
+                b += SkGetPackedB32(color);
+                count++;
+            }
+        }
+    }
+
+    if (count == 0) {
+        return SkPackARGB32NoCheck(SK_AlphaOPAQUE, 0, 0, 0);
+    } else {
+        return SkPackARGB32NoCheck(SK_AlphaOPAQUE,
+                                   r / count, g / count, b / count);
+    }
+}
+
+static uint16_t get_argb4444_neighbor_avg_color(const SkBitmap& bitmap,
+                                                int xOrig, int yOrig) {
+    uint8_t count = 0;
+    uint8_t r = 0;
+    uint8_t g = 0;
+    uint8_t b = 0;
+
+    for (int y = yOrig - 1; y <= yOrig + 1; y++) {
+        if (y < 0 || y >= bitmap.height()) {
+            continue;
+        }
+        uint16_t* src = bitmap.getAddr16(0, y);
+        for (int x = xOrig - 1; x <= xOrig + 1; x++) {
+            if (x < 0 || x >= bitmap.width()) {
+                continue;
+            }
+            if ((SkGetPackedA4444(src[x]) & 0x0F) != SK_AlphaTRANSPARENT) {
+                uint16_t color = remove_alpha_argb4444(src[x]);
+                r += SkGetPackedR4444(color);
+                g += SkGetPackedG4444(color);
+                b += SkGetPackedB4444(color);
+                count++;
+            }
+        }
+    }
+
+    if (count == 0) {
+        return SkPackARGB4444(SK_AlphaOPAQUE & 0x0F, 0, 0, 0);
+    } else {
+        return SkPackARGB4444(SK_AlphaOPAQUE & 0x0F,
+                                   r / count, g / count, b / count);
+    }
+}
+
+static SkBitmap unpremultiply_bitmap(const SkBitmap& bitmap,
+                                     const SkIRect& srcRect) {
+    SkBitmap outBitmap;
+    outBitmap.allocPixels(bitmap.info().makeWH(srcRect.width(), srcRect.height()));
+    int dstRow = 0;
+
+    SkAutoLockPixels outBitmapPixelLock(outBitmap);
+    SkAutoLockPixels bitmapPixelLock(bitmap);
+    switch (bitmap.colorType()) {
+        case kARGB_4444_SkColorType: {
+            for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+                uint16_t* dst = outBitmap.getAddr16(0, dstRow);
+                uint16_t* src = bitmap.getAddr16(0, y);
+                for (int x = srcRect.fLeft; x < srcRect.fRight; x++) {
+                    uint8_t a = SkGetPackedA4444(src[x]);
+                    // 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.
+                    if (a == (SK_AlphaTRANSPARENT & 0x0F)) {
+                        *dst = get_argb4444_neighbor_avg_color(bitmap, x, y);
+                    } else {
+                        *dst = remove_alpha_argb4444(src[x]);
+                    }
+                    dst++;
+                }
+                dstRow++;
+            }
+            break;
+        }
+        case kN32_SkColorType: {
+            for (int y = srcRect.fTop; y < srcRect.fBottom; y++) {
+                uint32_t* dst = outBitmap.getAddr32(0, dstRow);
+                uint32_t* src = bitmap.getAddr32(0, y);
+                for (int x = srcRect.fLeft; x < srcRect.fRight; x++) {
+                    uint8_t a = SkGetPackedA32(src[x]);
+                    if (a == SK_AlphaTRANSPARENT) {
+                        *dst = get_argb8888_neighbor_avg_color(bitmap, x, y);
+                    } else {
+                        *dst = remove_alpha_argb8888(src[x]);
+                    }
+                    dst++;
+                }
+                dstRow++;
+            }
+            break;
+        }
+        default:
+            SkASSERT(false);
+    }
+
+    outBitmap.setImmutable();
+
+    return outBitmap;
+}
+
+// static
+SkPDFImage* SkPDFImage::CreateImage(const SkBitmap& bitmap,
+                                    const SkIRect& srcRect) {
+    if (bitmap.colorType() == kUnknown_SkColorType) {
+        return NULL;
+    }
+
+    bool isTransparent = false;
+    SkAutoTDelete<SkStream> alphaData;
+    if (!bitmap.isOpaque()) {
+        // Note that isOpaque is not guaranteed to return false for bitmaps
+        // with alpha support but a completely opaque alpha channel,
+        // so alphaData may still be NULL if we have a completely opaque
+        // (or transparent) bitmap.
+        alphaData.reset(
+                extract_image_data(bitmap, srcRect, true, &isTransparent));
+    }
+    if (isTransparent) {
+        return NULL;
+    }
+
+    SkPDFImage* image;
+    SkColorType colorType = bitmap.colorType();
+    if (alphaData.get() != NULL && (kN32_SkColorType == colorType ||
+                                    kARGB_4444_SkColorType == colorType)) {
+        if (kN32_SkColorType == colorType) {
+            image = SkNEW_ARGS(SkPDFImage, (NULL, bitmap, false,
+                                            SkIRect::MakeWH(srcRect.width(),
+                                                            srcRect.height())));
+        } else {
+            SkBitmap unpremulBitmap = unpremultiply_bitmap(bitmap, srcRect);
+            image = SkNEW_ARGS(SkPDFImage, (NULL, unpremulBitmap, false,
+                                            SkIRect::MakeWH(srcRect.width(),
+                                                            srcRect.height())));
+        }
+    } else {
+        image = SkNEW_ARGS(SkPDFImage, (NULL, bitmap, false, srcRect));
+    }
+    if (alphaData.get() != NULL) {
+        SkAutoTUnref<SkPDFImage> mask(
+                SkNEW_ARGS(SkPDFImage, (alphaData.get(), bitmap, true, srcRect)));
+        image->insert("SMask", new SkPDFObjRef(mask))->unref();
+    }
+    return image;
+}
+
+SkPDFImage::~SkPDFImage() {}
+
+SkPDFImage::SkPDFImage(SkStream* stream,
+                       const SkBitmap& bitmap,
+                       bool isAlpha,
+                       const SkIRect& srcRect)
+    : fIsAlpha(isAlpha),
+      fSrcRect(srcRect) {
+
+    if (bitmap.isImmutable()) {
+        fBitmap = bitmap;
+    } else {
+        bitmap.deepCopyTo(&fBitmap);
+        fBitmap.setImmutable();
+    }
+
+    if (stream != NULL) {
+        this->setData(stream);
+        fStreamValid = true;
+    } else {
+        fStreamValid = false;
+    }
+
+    SkColorType colorType = fBitmap.colorType();
+
+    insertName("Type", "XObject");
+    insertName("Subtype", "Image");
+
+    bool alphaOnly = (kAlpha_8_SkColorType == colorType);
+
+    if (!isAlpha && alphaOnly) {
+        // For alpha only images, we stretch a single pixel of black for
+        // the color/shape part.
+        SkAutoTUnref<SkPDFInt> one(new SkPDFInt(1));
+        insert("Width", one.get());
+        insert("Height", one.get());
+    } else {
+        insertInt("Width", fSrcRect.width());
+        insertInt("Height", fSrcRect.height());
+    }
+
+    if (isAlpha || alphaOnly) {
+        insertName("ColorSpace", "DeviceGray");
+    } else if (kIndex_8_SkColorType == colorType) {
+        SkAutoLockPixels alp(fBitmap);
+        insert("ColorSpace",
+               make_indexed_color_space(fBitmap.getColorTable()))->unref();
+    } else {
+        insertName("ColorSpace", "DeviceRGB");
+    }
+
+    int bitsPerComp = 8;
+    if (kARGB_4444_SkColorType == colorType) {
+        bitsPerComp = 4;
+    }
+    insertInt("BitsPerComponent", bitsPerComp);
+
+    if (kRGB_565_SkColorType == colorType) {
+        SkASSERT(!isAlpha);
+        SkAutoTUnref<SkPDFInt> zeroVal(new SkPDFInt(0));
+        SkAutoTUnref<SkPDFScalar> scale5Val(
+                new SkPDFScalar(8.2258f));  // 255/2^5-1
+        SkAutoTUnref<SkPDFScalar> scale6Val(
+                new SkPDFScalar(4.0476f));  // 255/2^6-1
+        SkAutoTUnref<SkPDFArray> decodeValue(new SkPDFArray());
+        decodeValue->reserve(6);
+        decodeValue->append(zeroVal.get());
+        decodeValue->append(scale5Val.get());
+        decodeValue->append(zeroVal.get());
+        decodeValue->append(scale6Val.get());
+        decodeValue->append(zeroVal.get());
+        decodeValue->append(scale5Val.get());
+        insert("Decode", decodeValue.get());
+    }
+}
+
+SkPDFImage::SkPDFImage(SkPDFImage& pdfImage)
+    : SkPDFStream(pdfImage),
+      fBitmap(pdfImage.fBitmap),
+      fIsAlpha(pdfImage.fIsAlpha),
+      fSrcRect(pdfImage.fSrcRect),
+      fStreamValid(pdfImage.fStreamValid) {
+    // Nothing to do here - the image params are already copied in SkPDFStream's
+    // constructor, and the bitmap will be regenerated and encoded in
+    // populate.
+}
+
+bool SkPDFImage::populate(SkPDFCatalog* catalog) {
+    if (getState() == kUnused_State) {
+        // Initializing image data for the first time.
+        // Fallback method
+        if (!fStreamValid) {
+            SkAutoTDelete<SkStream> stream(
+                    extract_image_data(fBitmap, fSrcRect, fIsAlpha, NULL));
+            this->setData(stream);
+            fStreamValid = true;
+        }
+        return INHERITED::populate(catalog);
+    }
+#ifndef SK_NO_FLATE
+    else if (getState() == kNoCompression_State) {
+        // Compression has not been requested when the stream was first created,
+        // but the new catalog wants it compressed.
+        if (!getSubstitute()) {
+            SkPDFStream* substitute = SkNEW_ARGS(SkPDFImage, (*this));
+            setSubstitute(substitute);
+            catalog->setSubstitute(this, substitute);
+        }
+        return false;
+    }
+#endif  // SK_NO_FLATE
+    return true;
+}
+
+#if 0  // reenable when we can figure out the JPEG colorspace
+namespace {
+/**
+ *  This PDFObject assumes that its constructor was handed
+ *  Jpeg-encoded data that can be directly embedded into a PDF.
+ */
+class PDFJPEGImage : public SkPDFObject {
+    SkAutoTUnref<SkData> fData;
+    int fWidth;
+    int fHeight;
+public:
+    PDFJPEGImage(SkData* data, int width, int height)
+        : fData(SkRef(data)), fWidth(width), fHeight(height) {}
+    virtual void emitObject(
+            SkWStream* stream,
+            SkPDFCatalog* catalog, bool indirect) SK_OVERRIDE {
+        if (indirect) {
+            this->emitIndirectObject(stream, catalog);
+            return;
+        }
+        SkASSERT(fData.get());
+        const char kPrefaceFormat[] =
+            "<<"
+            "/Type /XObject\n"
+            "/Subtype /Image\n"
+            "/Width %d\n"
+            "/Height %d\n"
+            "/ColorSpace /DeviceRGB\n"  // or DeviceGray
+            "/BitsPerComponent 8\n"
+            "/Filter /DCTDecode\n"
+            "/ColorTransform 0\n"
+            "/Length " SK_SIZE_T_SPECIFIER "\n"
+            ">> stream\n";
+        SkString preface(
+                SkStringPrintf(kPrefaceFormat, fWidth, fHeight, fData->size()));
+        const char kPostface[] = "\nendstream";
+        stream->write(preface.c_str(), preface.size());
+        stream->write(fData->data(), fData->size());
+        stream->write(kPostface, sizeof(kPostface));
+    }
+};
+
+/**
+ *  If the bitmap is not subsetted, return its encoded data, if
+ *  availible.
+ */
+static inline SkData* ref_encoded_data(const SkBitmap& bm) {
+    if ((NULL == bm.pixelRef())
+        || !bm.pixelRefOrigin().isZero()
+        || (bm.info().dimensions() != bm.pixelRef()->info().dimensions())) {
+        return NULL;
+    }
+    return bm.pixelRef()->refEncodedData();
+}
+
+/*
+ *  This functions may give false negatives but no false positives.
+ */
+static bool is_jfif_jpeg(SkData* data) {
+    if (!data || (data->size() < 11)) {
+        return false;
+    }
+    const uint8_t bytesZeroToThree[] = {0xFF, 0xD8, 0xFF, 0xE0};
+    const uint8_t bytesSixToTen[] = {'J', 'F', 'I', 'F', 0};
+    // 0   1   2   3   4   5   6   7   8   9   10
+    // FF  D8  FF  E0  ??  ??  'J' 'F' 'I' 'F' 00 ...
+    return ((0 == memcmp(data->bytes(), bytesZeroToThree,
+                         sizeof(bytesZeroToThree)))
+            && (0 == memcmp(data->bytes() + 6, bytesSixToTen,
+                            sizeof(bytesSixToTen))));
+}
+}  // namespace
+#endif
+
+SkPDFObject* SkPDFCreateImageObject(SkPDFCanon* canon,
+                                    const SkBitmap& bitmap,
+                                    const SkIRect& subset) {
+    if (SkPDFObject* pdfBitmap = SkPDFBitmap::Create(canon, bitmap, subset)) {
+        return pdfBitmap;
+    }
+#if 0  // reenable when we can figure out the JPEG colorspace
+    if (SkIRect::MakeWH(bitmap.width(), bitmap.height()) == subset) {
+        SkAutoTUnref<SkData> encodedData(ref_encoded_data(bitmap));
+        if (is_jfif_jpeg(encodedData)) {
+            return SkNEW_ARGS(PDFJPEGImage,
+                              (encodedData, bitmap.width(), bitmap.height()));
+        }
+    }
+#endif
+    return SkPDFImage::CreateImage(bitmap, subset);
+}