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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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/*-
 *      Reads JPEG images from an InputStream and reports the
 *      image data to an InputStreamImageSource object.
 *
 * The native implementation of the JPEG image decoder was adapted from
 * release 6 of the free JPEG software from the Independent JPEG Group.
 */
package sun.awt.image;

import java.util.Vector;
import java.util.Hashtable;
import java.io.InputStream;
import java.io.IOException;
import java.awt.image.*;

JPEG Image converter
Author:Jim Graham
/** * JPEG Image converter * * @author Jim Graham */
public class JPEGImageDecoder extends ImageDecoder { private static ColorModel RGBcolormodel; private static ColorModel ARGBcolormodel; private static ColorModel Graycolormodel; private static final Class<?> InputStreamClass = InputStream.class; private static native void initIDs(Class<?> InputStreamClass); private ColorModel colormodel; static { java.security.AccessController.doPrivileged( new java.security.PrivilegedAction<Void>() { public Void run() { System.loadLibrary("javajpeg"); return null; } }); initIDs(InputStreamClass); RGBcolormodel = new DirectColorModel(24, 0xff0000, 0xff00, 0xff); ARGBcolormodel = ColorModel.getRGBdefault(); byte[] g = new byte[256]; for (int i = 0; i < 256; i++) { g[i] = (byte) i; } Graycolormodel = new IndexColorModel(8, 256, g, g, g); } private native void readImage(InputStream is, byte[] buf) throws ImageFormatException, IOException; Hashtable<String, Object> props = new Hashtable<>(); public JPEGImageDecoder(InputStreamImageSource src, InputStream is) { super(src, is); }
An error has occurred. Throw an exception.
/** * An error has occurred. Throw an exception. */
private static void error(String s1) throws ImageFormatException { throw new ImageFormatException(s1); } public boolean sendHeaderInfo(int width, int height, boolean gray, boolean hasalpha, boolean multipass) { setDimensions(width, height); setProperties(props); if (gray) { colormodel = Graycolormodel; } else { if (hasalpha) { colormodel = ARGBcolormodel; } else { colormodel = RGBcolormodel; } } setColorModel(colormodel); int flags = hintflags; if (!multipass) { flags |= ImageConsumer.SINGLEPASS; } setHints(hintflags); headerComplete(); return true; } public boolean sendPixels(int[] pixels, int y) { int count = setPixels(0, y, pixels.length, 1, colormodel, pixels, 0, pixels.length); if (count <= 0) { aborted = true; } return !aborted; } public boolean sendPixels(byte[] pixels, int y) { int count = setPixels(0, y, pixels.length, 1, colormodel, pixels, 0, pixels.length); if (count <= 0) { aborted = true; } return !aborted; }
produce an image from the stream.
/** * produce an image from the stream. */
public void produceImage() throws IOException, ImageFormatException { try { readImage(input, new byte[1024]); if (!aborted) { imageComplete(ImageConsumer.STATICIMAGEDONE, true); } } catch (IOException e) { if (!aborted) { throw e; } } finally { close(); } }
The ImageConsumer hints flag for a JPEG image.
/** * The ImageConsumer hints flag for a JPEG image. */
private static final int hintflags = ImageConsumer.TOPDOWNLEFTRIGHT | ImageConsumer.COMPLETESCANLINES | ImageConsumer.SINGLEFRAME; }