/*
* $RCSfile: MlibConvolveOpImage.java,v $
*
* Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* $Revision: 1.1 $
* $Date: 2005/02/11 04:55:52 $
* $State: Exp $
*/
package com.lightcrafts.media.jai.mlib;
import java.awt.Rectangle;
import java.awt.image.DataBuffer;
import java.awt.image.Raster;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import com.lightcrafts.mediax.jai.AreaOpImage;
import com.lightcrafts.mediax.jai.BorderExtender;
import com.lightcrafts.mediax.jai.ImageLayout;
import com.lightcrafts.mediax.jai.KernelJAI;
import java.util.Map;
import com.sun.medialib.mlib.*;
// import com.lightcrafts.media.jai.test.OpImageTester;
/**
* An OpImage class to perform convolution on a source image.
*
* <p> This class implements a convolution operation. Convolution is a
* spatial operation that computes each output sample by multiplying
* elements of a kernel with the samples surrounding a particular
* source sample.
*
* <p> For each destination sample, the kernel is rotated 180 degrees
* and its "key element" is placed over the source pixel corresponding
* with the destination pixel. The kernel elements are multiplied
* with the source pixels under them, and the resulting products are
* summed together to produce the destination sample value.
*
* <p> Example code for the convolution operation on a single sample
* dst[x][y] is as follows, assuming the kernel is of size M rows x N
* columns and has already been rotated through 180 degrees. The
* kernel's key element is located at position (xKey, yKey):
*
* <pre>
* dst[x][y] = 0;
* for (int i = -xKey; i < M - xKey; i++) {
* for (int j = -yKey; j < N - yKey; j++) {
* dst[x][y] += src[x + i][y + j] * kernel[xKey + i][yKey + j];
* }
* }
* </pre>
*
* <p> Convolution, or any neighborhood operation, leaves a band of
* pixels around the edges undefined, i.e., for a 3x3 kernel, only
* four kernel elements and four source pixels contribute to the
* destination pixel located at (0,0). Such pixels are not includined
* in the destination image, unless a non-null BorderExtender is provided.
*
* <p> The Kernel cannot be bigger in any dimension than the image data.
*
*
* @see KernelJAI
*/
final class MlibConvolveOpImage extends AreaOpImage {
/**
* The kernel with which to do the convolve operation.
*/
protected KernelJAI kernel;
/** Kernel variables. */
private int kw, kh, kx, ky;
float kData[];
double doublekData[];
int intkData[];
int shift = -1;
/**
* Creates a MlibConvolveOpImage given the image source and
* pre-rotated convolution kernel. The image dimensions are
* derived from the source image. The tile grid layout,
* SampleModel, and ColorModel may optionally be specified by an
* ImageLayout object.
*
* @param source a RenderedImage.
* @param extender a BorderExtender, or null.
* or null. If null, a default cache will be used.
* @param layout an ImageLayout optionally containing the tile grid layout,
* SampleModel, and ColorModel, or null.
* @param kernel the pre-rotated convolution KernelJAI.
*/
public MlibConvolveOpImage(RenderedImage source,
BorderExtender extender,
Map config,
ImageLayout layout,
KernelJAI kernel) {
super(source,
layout,
config,
true,
extender,
kernel.getLeftPadding(),
kernel.getRightPadding(),
kernel.getTopPadding(),
kernel.getBottomPadding());
this.kernel = kernel;
kw = kernel.getWidth();
kh = kernel.getHeight();
// this looks wrong, but it's right. AreaOpImage chops the image
// up so that the kernels are "centered" by selecting the
// appropriate source chunk (translating the source instead of the
// kernel). The X and Y offsets are taken care of there, not here.
kx = kw/2;
ky = kh/2;
kData = kernel.getKernelData();
int count = kw*kh;
// A little inefficient but figuring out what datatype
// mediaLibAccessor will want is tricky.
intkData = new int[count];
doublekData = new double[count];
for (int i = 0; i < count; i++) {
doublekData[i] = (double)kData[i];
}
}
private synchronized void setShift(int formatTag) {
if (shift == -1) {
int mediaLibDataType =
MediaLibAccessor.getMediaLibDataType(formatTag);
shift = Image.ConvKernelConvert(intkData,
doublekData,
kw,kh,
mediaLibDataType);
}
}
/**
* Performs convolution on a specified rectangle. The sources are
* cobbled.
*
* @param sources an array of source Rasters, guaranteed to provide all
* necessary source data for computing the output.
* @param dest a WritableRaster tile containing the area to be computed.
* @param destRect the rectangle within dest to be processed.
*/
protected void computeRect(Raster[] sources,
WritableRaster dest,
Rectangle destRect) {
Raster source = sources[0];
Rectangle srcRect = mapDestRect(destRect, 0);
int formatTag = MediaLibAccessor.findCompatibleTag(sources,dest);
MediaLibAccessor srcAccessor =
new MediaLibAccessor(source,srcRect,formatTag);
MediaLibAccessor dstAccessor =
new MediaLibAccessor(dest,destRect,formatTag);
int numBands = getSampleModel().getNumBands();
mediaLibImage[] srcML = srcAccessor.getMediaLibImages();
mediaLibImage[] dstML = dstAccessor.getMediaLibImages();
for (int i = 0; i < dstML.length; i++) {
switch (dstAccessor.getDataType()) {
case DataBuffer.TYPE_BYTE:
case DataBuffer.TYPE_USHORT:
case DataBuffer.TYPE_SHORT:
case DataBuffer.TYPE_INT:
if (shift == -1) {
setShift(formatTag);
}
Image.ConvMxN(dstML[i],
srcML[i], intkData, kw, kh, kx, ky, shift,
((1 << numBands)-1) ,
Constants.MLIB_EDGE_DST_NO_WRITE);
break;
case DataBuffer.TYPE_FLOAT:
case DataBuffer.TYPE_DOUBLE:
Image.ConvMxN_Fp(dstML[i],
srcML[i], doublekData, kw, kh, kx, ky,
((1 << numBands)-1) ,
Constants.MLIB_EDGE_DST_NO_WRITE);
break;
default:
String className = this.getClass().getName();
throw new RuntimeException(JaiI18N.getString("Generic2"));
}
}
if (dstAccessor.isDataCopy()) {
dstAccessor.copyDataToRaster();
}
}
// public static OpImage createTestImage(OpImageTester oit) {
// float data[] = {0.05f,0.10f,0.05f,
// 0.10f,0.40f,0.10f,
// 0.05f,0.10f,0.05f};
// KernelJAI k1 = new KernelJAI(3,3,1,1,data);
// return new MlibConvolveOpImage(oit.getSource(), null, null,
// new ImageLayout(oit.getSource()),
// k1);
// }
// public static void main (String args[]) {
// String classname = "com.lightcrafts.media.jai.mlib.MlibConvolveOpImage";
// OpImageTester.performDiagnostics(classname,args);
// }
}