From 933c771cb16377069f7651b19689591e6307bf5b Mon Sep 17 00:00:00 2001
From: Kenneth Russel <kbrussel@alum.mit.edu>
Date: Wed, 25 Jan 2006 07:28:35 +0000
Subject: Fixed Issue 196: Utility method to create thumbnails
Incorporated excellent patch from Romain Guy for creating high-quality
thumbnails.
git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@565 232f8b59-042b-4e1e-8c03-345bb8c30851
---
src/classes/com/sun/opengl/util/ImageUtil.java | 62 ++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
(limited to 'src/classes/com/sun/opengl/util/ImageUtil.java')
diff --git a/src/classes/com/sun/opengl/util/ImageUtil.java b/src/classes/com/sun/opengl/util/ImageUtil.java
index 1ce77fecf..f8981bd36 100755
--- a/src/classes/com/sun/opengl/util/ImageUtil.java
+++ b/src/classes/com/sun/opengl/util/ImageUtil.java
@@ -39,6 +39,7 @@
package com.sun.opengl.util;
+import java.awt.*;
import java.awt.image.*;
/** Utilities for dealing with images. */
@@ -61,4 +62,65 @@ public class ImageUtil {
raster.setDataElements(0, image.getHeight() - i - 1, image.getWidth(), 1, scanline1);
}
}
+
+ /**
+ * Creates a <code>BufferedImage</code> with a pixel format compatible with the graphics
+ * environment. The returned image can thus benefit from hardware accelerated operations
+ * in Java2D API.
+ *
+ * @param width The width of the image to be created
+ * @param height The height of the image to be created
+ *
+ * @return A instance of <code>BufferedImage</code> with a type compatible with the graphics card.
+ */
+ public static BufferedImage createCompatibleImage(int width, int height) {
+ GraphicsConfiguration configuration =
+ GraphicsEnvironment.getLocalGraphicsEnvironment().
+ getDefaultScreenDevice().getDefaultConfiguration();
+ return configuration.createCompatibleImage(width, height);
+ }
+
+ /**
+ * Creates a thumbnail from an image. A thumbnail is a scaled down version of the original picture.
+ * This method will retain the width to height ratio of the original picture and return a new
+ * instance of <code>BufferedImage</code>. The original picture is not modified.
+ *
+ * @param image The original image to sample down
+ * @param thumbWidth The width of the thumbnail to be created
+ *
+ * @throws IllegalArgumentException If thumbWidth is greater than image.getWidth()
+ *
+ * @return A thumbnail with the requested width or the original picture if thumbWidth = image.getWidth()
+ */
+ public static BufferedImage createThumbnail(BufferedImage image, int thumbWidth) {
+ // Thanks to Romain Guy for this utility
+ if (thumbWidth > image.getWidth()) {
+ throw new IllegalArgumentException("Thumbnail width must be greater than image width");
+ }
+
+ if (thumbWidth == image.getWidth()) {
+ return image;
+ }
+
+ float ratio = (float) image.getWidth() / (float) image.getHeight();
+ int width = image.getWidth();
+ BufferedImage thumb = image;
+
+ do {
+ width /= 2;
+ if (width < thumbWidth) {
+ width = thumbWidth;
+ }
+
+ BufferedImage temp = createCompatibleImage(width, (int) (width / ratio));
+ Graphics2D g2 = temp.createGraphics();
+ g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+ RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+ g2.drawImage(thumb, 0, 0, temp.getWidth(), temp.getHeight(), null);
+ g2.dispose();
+ thumb = temp;
+ } while (width != thumbWidth);
+
+ return thumb;
+ }
}
--
cgit v1.2.3