bmpimagereader.java

java1.6众多例子参考

                        iis.readFully(palette, 0, sizeOfPalette);

                        metadata.palette = palette;
                        metadata.paletteSize = (int)colorsUsed;
                    }
                    metadata.bmpVersion = VERSION_3_NT;

                    break;
                default:
                    throw new
                        RuntimeException(I18N.getString("BMPImageReader2"));
                }
            } else if (size == 108 || size == 124) {
                // Windows 4.x BMP
                if (size == 108)
                    metadata.bmpVersion = VERSION_4;
                else if (size == 124)
                    metadata.bmpVersion = VERSION_5;

                // rgb masks, valid only if comp is BI_BITFIELDS
                redMask = (int)iis.readUnsignedInt();
                greenMask = (int)iis.readUnsignedInt();
                blueMask = (int)iis.readUnsignedInt();
                // Only supported for 32bpp BI_RGB argb
                alphaMask = (int)iis.readUnsignedInt();
                long csType = iis.readUnsignedInt();
                int redX = iis.readInt();
                int redY = iis.readInt();
                int redZ = iis.readInt();
                int greenX = iis.readInt();
                int greenY = iis.readInt();
                int greenZ = iis.readInt();
                int blueX = iis.readInt();
                int blueY = iis.readInt();
                int blueZ = iis.readInt();
                long gammaRed = iis.readUnsignedInt();
                long gammaGreen = iis.readUnsignedInt();
                long gammaBlue = iis.readUnsignedInt();

                if (size == 124) {
                    metadata.intent = iis.readInt();
                    profileData = iis.readInt();
                    profileSize = iis.readInt();
                    iis.skipBytes(4);
                }

                metadata.colorSpace = (int)csType;

                if (csType == LCS_CALIBRATED_RGB) {
                    // All the new fields are valid only for this case
                    metadata.redX = redX;
                    metadata.redY = redY;
                    metadata.redZ = redZ;
                    metadata.greenX = greenX;
                    metadata.greenY = greenY;
                    metadata.greenZ = greenZ;
                    metadata.blueX = blueX;
                    metadata.blueY = blueY;
                    metadata.blueZ = blueZ;
                    metadata.gammaRed = (int)gammaRed;
                    metadata.gammaGreen = (int)gammaGreen;
                    metadata.gammaBlue = (int)gammaBlue;
                }

                // Read in the palette
                int numberOfEntries = (int)((bitmapOffset-14-size) / 4);
                int sizeOfPalette = numberOfEntries*4;
                palette = new byte[sizeOfPalette];
                iis.readFully(palette, 0, sizeOfPalette);
                metadata.palette = palette;
                metadata.paletteSize = numberOfEntries;

                switch ((int)compression) {
                case BI_JPEG:
                case BI_PNG:
                    if (size == 108) {
                        imageType = VERSION_4_XP_EMBEDDED;
                    } else if (size == 124) {
                        imageType = VERSION_5_XP_EMBEDDED;
                    }
                    break;
                default:
                    if (bitsPerPixel == 1) {
                        imageType = VERSION_4_1_BIT;
                    } else if (bitsPerPixel == 4) {
                        imageType = VERSION_4_4_BIT;
                    } else if (bitsPerPixel == 8) {
                        imageType = VERSION_4_8_BIT;
                    } else if (bitsPerPixel == 16) {
                        imageType = VERSION_4_16_BIT;
                        if ((int)compression == BI_RGB) {
                            redMask = 0x7C00;
                            greenMask = 0x3E0;
                            blueMask = 0x1F;
                        }
                    } else if (bitsPerPixel == 24) {
                        imageType = VERSION_4_24_BIT;
                    } else if (bitsPerPixel == 32) {
                        imageType = VERSION_4_32_BIT;
                        if ((int)compression == BI_RGB) {
                            redMask   = 0x00FF0000;
                            greenMask = 0x0000FF00;
                            blueMask  = 0x000000FF;
                        }
                    }
                    
                    metadata.redMask = redMask;
                    metadata.greenMask = greenMask;
                    metadata.blueMask = blueMask;
                    metadata.alphaMask = alphaMask;
                }
            } else {
                throw new
                    RuntimeException(I18N.getString("BMPImageReader3"));
            }
        }

        if (height > 0) {
            // bottom up image
            isBottomUp = true;
        } else {
            // top down image
            isBottomUp = false;
            height = Math.abs(height);
        }

        // Reset Image Layout so there's only one tile.
        //Define the color space
        ColorSpace colorSpace = ColorSpace.getInstance(ColorSpace.CS_sRGB);
        if (metadata.colorSpace == PROFILE_LINKED ||
            metadata.colorSpace == PROFILE_EMBEDDED) {

            iis.mark();
            iis.skipBytes(profileData - size);
            byte[] profile = new byte[profileSize];
            iis.readFully(profile, 0, profileSize);
            iis.reset();

            try {
                if (metadata.colorSpace == PROFILE_LINKED)
                    colorSpace =
                        new ICC_ColorSpace(ICC_Profile.getInstance(new String(profile)));
                else
                    colorSpace =
                        new ICC_ColorSpace(ICC_Profile.getInstance(profile));
            } catch (Exception e) {
                colorSpace = ColorSpace.getInstance(ColorSpace.CS_sRGB);
            }
        }

        if (bitsPerPixel == 0 ||
            compression == BI_JPEG || compression == BI_PNG )
        {
            // the colorModel and sampleModel will be initialzed
            // by the  reader of embedded image
            colorModel = null;
            sampleModel = null;
        } else if (bitsPerPixel == 1 || bitsPerPixel == 4 || bitsPerPixel == 8) {
            // When number of bitsPerPixel is <= 8, we use IndexColorModel.
            numBands = 1;

            if (bitsPerPixel == 8) {
                int[] bandOffsets = new int[numBands];
                for (int i = 0; i < numBands; i++) {
                    bandOffsets[i] = numBands -1 -i;
                }
                sampleModel =
                    new PixelInterleavedSampleModel(DataBuffer.TYPE_BYTE,
                                                    width, height,
                                                    numBands,
                                                    numBands * width,
                                                    bandOffsets);
            } else {
                // 1 and 4 bit pixels can be stored in a packed format.
                sampleModel =
                    new MultiPixelPackedSampleModel(DataBuffer.TYPE_BYTE,
                                                    width, height,
                                                    bitsPerPixel);
            }

            // Create IndexColorModel from the palette.
            byte r[], g[], b[];
            if (imageType == VERSION_2_1_BIT ||
                imageType == VERSION_2_4_BIT ||
                imageType == VERSION_2_8_BIT) {


                size = palette.length/3;

                if (size > 256) {
                    size = 256;
                }

                int off;
                r = new byte[(int)size];
                g = new byte[(int)size];
                b = new byte[(int)size];
                for (int i=0; i<(int)size; i++) {
                    off = 3 * i;
                    b[i] = palette[off];
                    g[i] = palette[off+1];
                    r[i] = palette[off+2];
                }
            } else {
                size = palette.length/4;

                if (size > 256) {
                    size = 256;
                }

                int off;
                r = new byte[(int)size];
                g = new byte[(int)size];
                b = new byte[(int)size];
                for (int i=0; i<size; i++) {
                    off = 4 * i;
                    b[i] = palette[off];
                    g[i] = palette[off+1];
                    r[i] = palette[off+2];
                }
            }

            if (ImageUtil.isIndicesForGrayscale(r, g, b))
                colorModel =
                    ImageUtil.createColorModel(null, sampleModel);
            else
                colorModel = new IndexColorModel(bitsPerPixel, (int)size, r, g, b);
        } else if (bitsPerPixel == 16) {
            numBands = 3;
            sampleModel =
                new SinglePixelPackedSampleModel(DataBuffer.TYPE_USHORT,
                                                 width, height,
                                                 new int[] {redMask, greenMask, blueMask});

            colorModel =
                new DirectColorModel(colorSpace,
                                     16, redMask, greenMask, blueMask, 0,
                                     false, DataBuffer.TYPE_USHORT);
		   
        } else if (bitsPerPixel == 32) {
            numBands = alphaMask == 0 ? 3 : 4;

            // The number of bands in the SampleModel is determined by
            // the length of the mask array passed in.
            int[] bitMasks = numBands == 3 ?
                new int[] {redMask, greenMask, blueMask} :
                new int[] {redMask, greenMask, blueMask, alphaMask};

                sampleModel =
                    new SinglePixelPackedSampleModel(DataBuffer.TYPE_INT,
                                                     width, height,
                                                     bitMasks);

                colorModel =
                    new DirectColorModel(colorSpace,
                                         32, redMask, greenMask, blueMask, alphaMask,
                                         false, DataBuffer.TYPE_INT);
        } else {
            numBands = 3;
            // Create SampleModel
            int[] bandOffsets = new int[numBands];
            for (int i = 0; i < numBands; i++) {
                bandOffsets[i] = numBands -1 -i;
            }

            sampleModel =
                new PixelInterleavedSampleModel(DataBuffer.TYPE_BYTE,
                                                width, height,
                                                numBands,
                                                numBands * width,
                                                bandOffsets);

            colorModel =
                ImageUtil.createColorModel(colorSpace, sampleModel);
        }

        originalSampleModel = sampleModel;
        originalColorModel = colorModel;

        // Reset to the start of bitmap; then jump to the
        //start of image data
        iis.reset();
        iis.skipBytes(bitmapOffset);
        gotHeader = true;       
    }

    public Iterator getImageTypes(int imageIndex)
      throws IOException {
        checkIndex(imageIndex);
        readHeader();
        ArrayList list = new ArrayList(1);
        list.add(new ImageTypeSpecifier(originalColorModel,
                                        originalSampleModel));
        return list.iterator();
    }

    public ImageReadParam getDefaultReadParam() {
        return new ImageReadParam();
    }

    public IIOMetadata getImageMetadata(int imageIndex)
      throws IOException {
        checkIndex(imageIndex);
        if (metadata == null) {
            readHeader();
        }
        return metadata;
    }

    public IIOMetadata getStreamMetadata() throws IOException {
        return null;
    }

    public boolean isRandomAccessEasy(int imageIndex) throws IOException {
        checkIndex(imageIndex);
        readHeader();
        return metadata.compression == BI_RGB;
    }

    public BufferedImage read(int imageIndex, ImageReadParam param)
        throws IOException {

        if (iis == null) {
            throw new IllegalStateException(I18N.getString("BMPImageReader5"));
        }

        checkIndex(imageIndex);
        clearAbortRequest();
        processImageStarted(imageIndex);

        if (param == null)
            param = getDefaultReadParam();

        //read header
        readHeader();

        sourceRegion = new Rectangle(0, 0, 0, 0);
        destinationRegion = new Rectangle(0, 0, 0, 0);

        computeRegions(param, this.width, this.height,
                       param.getDestination(),
                       sourceRegion,
                       destinationRegion);

        scaleX = param.getSourceXSubsampling();
        scaleY = param.getSourceYSubsampling();