| /* AreaAveragingScaleFilter.java -- Java class for filtering images |
| Copyright (C) 1999,2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.awt.image; |
| |
| /** |
| * This filter should produce images which do not have image artifacts |
| * like broken lines which were originally unbroken. The cost is of |
| * course speed. Using bi-linear interpolation here against 4 pixel |
| * points should give the desired results although Sun does not |
| * specify what the exact algorithm should be. |
| * <br> |
| * |
| * @author C. Brian Jones (cbj@gnu.org) |
| */ |
| public class AreaAveragingScaleFilter extends ReplicateScaleFilter |
| { |
| /** |
| * Construct an instance of <code>AreaAveragingScaleFilter</code> which |
| * should be used in conjunction with a <code>FilteredImageSource</code> |
| * object. |
| * |
| * @param width the width of the destination image |
| * @param height the height of the destination image |
| */ |
| public AreaAveragingScaleFilter(int width, int height) { |
| super(width, height); |
| } |
| |
| /** |
| * The <code>ImageProducer</code> should call this method with a |
| * bit mask of hints from any of <code>RANDOMPIXELORDER</code>, |
| * <code>TOPDOWNLEFTRIGHT</code>, <code>COMPLETESCANLINES</code>, |
| * <code>SINGLEPASS</code>, <code>SINGLEFRAME</code> from the |
| * <code>ImageConsumer</code> interface. |
| * <br> |
| * FIXME - more than likely Sun's implementation desires |
| * <code>TOPDOWNLEFTRIGHT</code> order and this method is overloaded here |
| * in order to assure that mask is part of the hints added to |
| * the consumer. |
| * |
| * @param flags a bit mask of hints |
| * @see ImageConsumer |
| */ |
| public void setHints(int flags) |
| { |
| if (consumer != null) |
| consumer.setHints(flags); |
| } |
| |
| /** |
| * This function delivers a rectangle of pixels where any |
| * pixel(m,n) is stored in the array as a <code>byte</code> at |
| * index (n * scansize + m + offset). |
| * |
| * @param x the x coordinate of the rectangle |
| * @param y the y coordinate of the rectangle |
| * @param w the width of the rectangle |
| * @param h the height of the rectangle |
| * @param model the <code>ColorModel</code> used to translate the pixels |
| * @param pixels the array of pixel values |
| * @param offset the index of the first pixels in the <code>pixels</code> array |
| * @param scansize the width to use in extracting pixels from the <code>pixels</code> array |
| */ |
| public void setPixels(int x, int y, int w, int h, |
| ColorModel model, byte[] pixels, int offset, int scansize) |
| { |
| double rx = ((double) srcWidth) / destWidth; |
| double ry = ((double) srcHeight) / destHeight; |
| |
| int destScansize = (int) Math.round(scansize / rx); |
| |
| byte[] destPixels = averagePixels(x, y, w, h, |
| model, pixels, offset, scansize, |
| rx, ry, destScansize); |
| |
| if (consumer != null) |
| consumer.setPixels((int) Math.floor(x/rx), (int) Math.floor(y/ry), |
| (int) Math.ceil(w/rx), (int) Math.ceil(h/ry), |
| model, destPixels, 0, destScansize); |
| } |
| |
| /** |
| * This function delivers a rectangle of pixels where any |
| * pixel(m,n) is stored in the array as an <code>int</code> at |
| * index (n * scansize + m + offset). |
| * |
| * @param x the x coordinate of the rectangle |
| * @param y the y coordinate of the rectangle |
| * @param w the width of the rectangle |
| * @param h the height of the rectangle |
| * @param model the <code>ColorModel</code> used to translate the pixels |
| * @param pixels the array of pixel values |
| * @param offset the index of the first pixels in the <code>pixels</code> array |
| * @param scansize the width to use in extracting pixels from the <code>pixels</code> array |
| */ |
| public void setPixels(int x, int y, int w, int h, |
| ColorModel model, int[] pixels, int offset, int scansize) |
| { |
| double rx = ((double) srcWidth) / destWidth; |
| double ry = ((double) srcHeight) / destHeight; |
| |
| int destScansize = (int) Math.round(scansize / rx); |
| |
| int[] destPixels = averagePixels(x, y, w, h, |
| model, pixels, offset, scansize, |
| rx, ry, destScansize); |
| |
| if (consumer != null) |
| consumer.setPixels((int) Math.floor(x/rx), (int) Math.floor(y/ry), |
| (int) Math.ceil(w/rx), (int) Math.ceil(h/ry), |
| model, destPixels, 0, destScansize); |
| } |
| |
| /** |
| * This is a really terrible implementation, |
| * since it uses the nearest-neighbor method. This filter is rarely used though. |
| * |
| * @param srcx, srcy - Source rectangle upper-left corner |
| * @param srcw, srch - Source rectangle width and height |
| * @param model - Pixel color model |
| * @param srcPixels - Source pixel data. |
| * @param srcOffset - Starting offset into the source pixel data array. |
| * @param srcScansize - Source array scanline size. |
| * @param rx,ry - Scaling factor. |
| * @param dstScansize - Destination array scanline size. |
| */ |
| private byte[] averagePixels(int srcx, int srcy, int srcw, int srch, |
| ColorModel model, byte[] srcPixels, |
| int srcOffset, int srcScansize, |
| double rx, double ry, int destScansize) |
| { |
| int destW = (int) Math.ceil(srcw/rx); |
| int destH = (int) Math.ceil(srch/ry); |
| byte[] destPixels = new byte[ destW * destH ]; |
| int sx, sy; |
| |
| int w = (int)Math.ceil(rx); |
| int h = (int)Math.ceil(ry); |
| |
| for(int x = 0; x < destW; x++) |
| for(int y = 0; y < destH; y++) |
| { |
| sx = (int) (x * rx); |
| sy = (int) (y * ry); |
| |
| int r,g,b,a; |
| r = g = b = a = 0; |
| |
| for(int i = 0; i < w; i++) |
| { |
| for(int j = 0; j < h; j++) |
| { |
| int idx = srcx + sx + i + (srcy + sy + j)*srcScansize; |
| r += model.getRed(srcPixels[ idx ]); |
| g += model.getGreen(srcPixels[ idx ]); |
| b += model.getBlue(srcPixels[ idx ]); |
| a += model.getAlpha(srcPixels[ idx ]); |
| } |
| } |
| |
| r = r / (w * h); |
| g = g / (w * h); |
| b = b / (w * h); |
| a = a / (w * h); |
| |
| // Does this really work? |
| destPixels[x + destScansize*y] = (byte)model.getDataElement |
| (new int[]{r, g, b, a}, 0); |
| } |
| |
| return destPixels; |
| } |
| |
| /** |
| * This is a really terrible implementation, |
| * since it uses the nearest-neighbor method. This filter is rarely used though. |
| * |
| * @param srcx, srcy - Source rectangle upper-left corner |
| * @param srcw, srch - Source rectangle width and height |
| * @param model - Pixel color model |
| * @param srcPixels - Source pixel data. |
| * @param srcOffset - Starting offset into the source pixel data array. |
| * @param srcScansize - Source array scanline size. |
| * @param rx,ry - Scaling factor. |
| * @param dstScansize - Destination array scanline size. |
| */ |
| private int[] averagePixels(int srcx, int srcy, int srcw, int srch, |
| ColorModel model, int[] srcPixels, |
| int srcOffset, int srcScansize, |
| double rx, double ry, int destScansize) |
| { |
| int destW = (int) Math.ceil(srcw/rx); |
| int destH = (int) Math.ceil(srch/ry); |
| int[] destPixels = new int[ destW * destH ]; |
| int sx, sy; |
| |
| int w = (int)Math.ceil(rx); |
| int h = (int)Math.ceil(ry); |
| |
| for(int x = 0; x < destW; x++) |
| for(int y = 0; y < destH; y++) |
| { |
| sx = (int) (x * rx); |
| sy = (int) (y * ry); |
| |
| int r,g,b,a; |
| r = g = b = a = 0; |
| |
| for(int i = 0; i < w; i++) |
| { |
| for(int j = 0; j < h; j++) |
| { |
| int idx = srcx + sx + i + (srcy + sy + j)*srcScansize; |
| r += model.getRed(srcPixels[ idx ]); |
| g += model.getGreen(srcPixels[ idx ]); |
| b += model.getBlue(srcPixels[ idx ]); |
| a += model.getAlpha(srcPixels[ idx ]); |
| } |
| } |
| |
| r = r / (w * h); |
| g = g / (w * h); |
| b = b / (w * h); |
| a = a / (w * h); |
| |
| destPixels[x + destScansize*y] = model.getDataElement |
| (new int[]{r, g, b, a}, 0); |
| } |
| |
| return destPixels; |
| } |
| } |
| |