Changeset 8729 in josm for trunk/src/org/openstreetmap/josm/gui/layer/ImageryLayer.java

Timestamp:

2015-09-04T10:32:05+02:00 (11 years ago)

Author:

simon04

Message:

fix #10417 - Selectable Gamma value for background imagery

File:

• trunk/src/org/openstreetmap/josm/gui/layer/ImageryLayer.java (modified) (4 diffs)

trunk/src/org/openstreetmap/josm/gui/layer/ImageryLayer.java

@@ -20 +20 @@
 import java.awt.image.ConvolveOp;
 import java.awt.image.Kernel;
+import java.awt.image.LookupOp;
+import java.awt.image.ShortLookupTable;
 import java.text.AttributedCharacterIterator;
 import java.text.AttributedString;
@@ -75 +77 @@
     protected double dy = 0.0;
 
+    protected GammaImageProcessor gammaImageProcessor = new GammaImageProcessor();
+
     private final ImageryAdjustAction adjustAction = new ImageryAdjustAction(this);
 
@@ -92 +96 @@
         }
         addImageProcessor(createSharpener(PROP_SHARPEN_LEVEL.get()));
+        addImageProcessor(gammaImageProcessor);
     }
 
@@ -247 +252 @@
         BufferedImageOp op = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);
         return createImageProcessor(op, false);
+    }
+
+    /**
+     * An image processor which adjusts the gamma value of an image.
+     */
+    public static class GammaImageProcessor implements ImageProcessor {
+        private double gamma = 1;
+        final short[] gammaChange = new short[256];
+        private LookupOp op3 = new LookupOp(new ShortLookupTable(0, new short[][]{gammaChange, gammaChange, gammaChange}), null);
+        private LookupOp op4 = new LookupOp(new ShortLookupTable(0, new short[][]{gammaChange, gammaChange, gammaChange, gammaChange}), null);
+
+        /**
+         * Returns the currently set gamma value.
+         */
+        public double getGamma() {
+            return gamma;
+        }
+
+        /**
+         * Sets a new gamma value, {@code 1} stands for no correction.
+         */
+        public void setGamma(double gamma) {
+            this.gamma = gamma;
+            for (int i = 0; i < 256; i++) {
+                gammaChange[i] = (short) (255 * Math.pow(i / 255., gamma));
+            }
+        }
+
+        private LookupOp getOp(int bands) {
+            if (gamma == 1) {
+                return null;
+            } else if (bands == 3) {
+                return op3;
+            } else if (bands == 4) {
+                return op4;
+            } else {
+                return null;
+            }
+        }
+
+        @Override
+        public BufferedImage process(BufferedImage image) {
+            final LookupOp op = getOp(image.getRaster().getNumBands());
+            final BufferedImage to = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);
+            return op == null ? image : op.filter(image, to);
+        }
+    }
+
+    /**
+     * Returns the currently set gamma value.
+     */
+    public double getGamma() {
+        return gammaImageProcessor.getGamma();
+    }
+
+    /**
+     * Sets a new gamma value, {@code 1} stands for no correction.
+     */
+    public void setGamma(double gamma) {
+        gammaImageProcessor.setGamma(gamma);
     }