FilterAsAlphaRed.java 文件源码

/**
 * Construct an alpah channel from the given src, according to
 * the SVG masking rules.
 *
 * @param src The image to convert to an alpha channel (mask image)
 */
public FilterAsAlphaRed(CachableRed src) {
    super(new Any2LumRed(src),src.getBounds(), 
          new ComponentColorModel
              (ColorSpace.getInstance(ColorSpace.CS_GRAY),
               new int [] {8}, false, false,
               Transparency.OPAQUE, 
               DataBuffer.TYPE_BYTE),
          new PixelInterleavedSampleModel
              (DataBuffer.TYPE_BYTE, 
               src.getSampleModel().getWidth(),
               src.getSampleModel().getHeight(),
               1, src.getSampleModel().getWidth(),
               new int [] { 0 }),
          src.getTileGridXOffset(),
          src.getTileGridYOffset(),
          null);

    props.put(ColorSpaceHintKey.PROPERTY_COLORSPACE,
              ColorSpaceHintKey.VALUE_COLORSPACE_ALPHA);
}