diff options
Diffstat (limited to 'java/awt/image/ConvolveOp.java')
| -rw-r--r-- | java/awt/image/ConvolveOp.java | 128 |
1 files changed, 89 insertions, 39 deletions
diff --git a/java/awt/image/ConvolveOp.java b/java/awt/image/ConvolveOp.java index ffb834874..cd3b01131 100644 --- a/java/awt/image/ConvolveOp.java +++ b/java/awt/image/ConvolveOp.java @@ -38,7 +38,6 @@ exception statement from your version. */ package java.awt.image; -import java.awt.Graphics2D; import java.awt.RenderingHints; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; @@ -51,11 +50,13 @@ import java.awt.geom.Rectangle2D; * with elements in the kernel to compute a new pixel. * * Each band in a Raster is convolved and copied to the destination Raster. + * For BufferedImages, convolution is applied to all components. Color + * conversion will be applied if needed. * - * For BufferedImages, convolution is applied to all components. If the - * source is not premultiplied, the data will be premultiplied before - * convolving. Premultiplication will be undone if the destination is not - * premultiplied. Color conversion will be applied if needed. + * Note that this filter ignores whether the source or destination is alpha + * premultiplied. The reference spec states that data will be premultiplied + * prior to convolving and divided back out afterwards (if needed), but testing + * has shown that this is not the case with their implementation. * * @author jlquinn@optonline.net */ @@ -104,59 +105,83 @@ public class ConvolveOp implements BufferedImageOp, RasterOp hints = null; } - - /* (non-Javadoc) - * @see java.awt.image.BufferedImageOp#filter(java.awt.image.BufferedImage, - * java.awt.image.BufferedImage) + /** + * Converts the source image using the kernel specified in the + * constructor. The resulting image is stored in the destination image if one + * is provided; otherwise a new BufferedImage is created and returned. + * + * The source and destination BufferedImage (if one is supplied) must have + * the same dimensions. + * + * @param src The source image. + * @param dst The destination image. + * @throws IllegalArgumentException if the rasters and/or color spaces are + * incompatible. + * @return The convolved image. */ public final BufferedImage filter(BufferedImage src, BufferedImage dst) { if (src == dst) - throw new IllegalArgumentException(); + throw new IllegalArgumentException("Source and destination images " + + "cannot be the same."); if (dst == null) dst = createCompatibleDestImage(src, src.getColorModel()); // Make sure source image is premultiplied BufferedImage src1 = src; - if (!src.isPremultiplied) + // The spec says we should do this, but mauve testing shows that Sun's + // implementation does not check this. + /* + if (!src.isAlphaPremultiplied()) { src1 = createCompatibleDestImage(src, src.getColorModel()); src.copyData(src1.getRaster()); src1.coerceData(true); } + */ BufferedImage dst1 = dst; - if (!src.getColorModel().equals(dst.getColorModel())) + if (src1.getColorModel().getColorSpace().getType() != dst.getColorModel().getColorSpace().getType()) dst1 = createCompatibleDestImage(src, src.getColorModel()); filter(src1.getRaster(), dst1.getRaster()); + // Since we don't coerceData above, we don't need to divide it back out. + // This is wrong (one mauve test specifically tests converting a non- + // premultiplied image to a premultiplied image, and it shows that Sun + // simply ignores the premultipled flag, contrary to the spec), but we + // mimic it for compatibility. + /* + if (! dst.isAlphaPremultiplied()) + dst1.coerceData(false); + */ + + // Convert between color models if needed if (dst1 != dst) - { - // Convert between color models. - // TODO Check that premultiplied alpha is handled correctly here. - Graphics2D gg = dst.createGraphics(); - gg.setRenderingHints(hints); - gg.drawImage(dst1, 0, 0, null); - gg.dispose(); - } - + new ColorConvertOp(hints).filter(dst1, dst); + return dst; } - /* (non-Javadoc) - * @see - * java.awt.image.BufferedImageOp#createCompatibleDestImage(java.awt.image.BufferedImage, - * java.awt.image.ColorModel) + /** + * Creates an empty BufferedImage with the size equal to the source and the + * correct number of bands. The new image is created with the specified + * ColorModel, or if no ColorModel is supplied, an appropriate one is chosen. + * + * @param src The source image. + * @param dstCM A color model for the destination image (may be null). + * @return The new compatible destination image. */ public BufferedImage createCompatibleDestImage(BufferedImage src, - ColorModel dstCM) + ColorModel dstCM) { - // FIXME: set properties to those in src - return new BufferedImage(dstCM, - src.getRaster().createCompatibleWritableRaster(), - src.isPremultiplied, null); + if (dstCM != null) + return new BufferedImage(dstCM, + src.getRaster().createCompatibleWritableRaster(), + src.isAlphaPremultiplied(), null); + + return new BufferedImage(src.getWidth(), src.getHeight(), src.getType()); } /* (non-Javadoc) @@ -168,6 +193,8 @@ public class ConvolveOp implements BufferedImageOp, RasterOp } /** + * Get the edge condition for this Op. + * * @return The edge condition. */ public int getEdgeCondition() @@ -185,9 +212,22 @@ public class ConvolveOp implements BufferedImageOp, RasterOp return (Kernel) kernel.clone(); } - /* (non-Javadoc) - * @see java.awt.image.RasterOp#filter(java.awt.image.Raster, - * java.awt.image.WritableRaster) + /** + * Converts the source raster using the kernel specified in the constructor. + * The resulting raster is stored in the destination raster if one is + * provided; otherwise a new WritableRaster is created and returned. + * + * If the convolved value for a sample is outside the range of [0-255], it + * will be clipped. + * + * The source and destination raster (if one is supplied) cannot be the same, + * and must also have the same dimensions. + * + * @param src The source raster. + * @param dest The destination raster. + * @throws IllegalArgumentException if the rasters identical. + * @throws ImagingOpException if the convolution is not possible. + * @return The transformed raster. */ public final WritableRaster filter(Raster src, WritableRaster dest) { @@ -228,7 +268,16 @@ public class ConvolveOp implements BufferedImageOp, RasterOp v += tmp[tmp.length - i - 1] * kvals[i]; // FIXME: in the above line, I've had to reverse the order of // the samples array to make the tests pass. I haven't worked - // out why this is necessary. + // out why this is necessary. + + // This clipping is pretty strange, and seems to be hard-coded + // at 255 (regardless of the raster's datatype or transfertype). + // But it's what the reference does. + if (v > 255) + v = 255; + if (v < 0) + v = 0; + dest.setSample(x + kernel.getXOrigin(), y + kernel.getYOrigin(), b, v); } @@ -310,13 +359,14 @@ public class ConvolveOp implements BufferedImageOp, RasterOp return src.getBounds(); } - /** Return corresponding destination point for source point. + /** + * Returns the corresponding destination point for a source point. Because + * this is not a geometric operation, the destination and source points will + * be identical. * - * ConvolveOp will return the value of src unchanged. * @param src The source point. - * @param dst The destination point. - * @see java.awt.image.RasterOp#getPoint2D(java.awt.geom.Point2D, - * java.awt.geom.Point2D) + * @param dst The transformed destination point. + * @return The transformed destination point. */ public final Point2D getPoint2D(Point2D src, Point2D dst) { |