--- /dev/null
+package tim.prune.gui;
+
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.Image;
+import java.awt.image.BufferedImage;
+import java.awt.image.ConvolveOp;
+import java.awt.image.Kernel;
+
+import javax.swing.ImageIcon;
+
+/**
+ * Class for providing generic image processing functions
+ */
+public abstract class ImageUtils
+{
+ private static final float SMOOTH_FACTOR = 0.008f;
+ private static ConvolveOp CONVOLVER = null;
+
+ /** Static block for initialization */
+ static
+ {
+ float[] smoothMatrix = {
+ 0, SMOOTH_FACTOR, 0,
+ SMOOTH_FACTOR, 1-(SMOOTH_FACTOR*4), SMOOTH_FACTOR,
+ 0, SMOOTH_FACTOR, 0
+ };
+ CONVOLVER = new ConvolveOp(new Kernel(3, 3, smoothMatrix));
+ }
+
+
+ /**
+ * Create a scaled and smoothed image according to the specified size
+ * @param inImage image to scale
+ * @param inWidth width to scale to
+ * @param inHeight height to scale to
+ * @return BufferedImage containing scaled result
+ */
+ public static BufferedImage createScaledImage(Image inImage, int inWidth, int inHeight)
+ {
+ if (inWidth <= 0 || inHeight <= 0) {
+ return null;
+ }
+ // create smaller image and force its loading
+ Image smallerImage = inImage.getScaledInstance(inWidth, inHeight, Image.SCALE_SMOOTH);
+ Image tempImage = new ImageIcon(smallerImage).getImage();
+ tempImage.getWidth(null);
+
+ // create buffered image to do transform
+ BufferedImage buffer = new BufferedImage(inWidth, inHeight, BufferedImage.TYPE_INT_RGB);
+ // copy scaled picture into buffer
+ Graphics buffG = buffer.getGraphics();
+ buffG.drawImage(smallerImage, 0, 0, inWidth, inHeight, null);
+ buffG.dispose();
+
+ // clear variables
+ smallerImage = null; tempImage = null;
+ // smooth scaled image using a normalized 3x3 matrix - taking next neighbour
+ buffer = CONVOLVER.filter(buffer, null);
+
+ return buffer;
+ }
+
+
+ /**
+ * Work out the max size of a thumbnail
+ * @param inOrigWidth width of original picture
+ * @param inOrigHeight height of original picture
+ * @param inMaxWidth max width of thumbnail
+ * @param inMaxHeight max height of thumbnail
+ * @return size of thumbnail as Dimension
+ */
+ public static Dimension getThumbnailSize(int inOrigWidth, int inOrigHeight, int inMaxWidth, int inMaxHeight)
+ {
+ if (inMaxWidth <= 0 || inMaxHeight <= 0) {return new Dimension(1, 1);}
+ // work out maximum zoom ratio available so that thumbnail isn't too big
+ double xZoom = inMaxWidth * 1.0 / inOrigWidth;
+ double yZoom = inMaxHeight * 1.0 / inOrigHeight;
+ double zoom = (xZoom > yZoom?yZoom:xZoom);
+ // Don't make thumbnail bigger than picture
+ if (zoom > 1.0) {return new Dimension(inOrigWidth, inOrigHeight);}
+
+ // calculate new width and height
+ final int xSize = (int) (zoom * inOrigWidth);
+ final int ySize = (int) (zoom * inOrigHeight);
+ if (xSize <= 0 || ySize <= 0) {return new Dimension(1, 1);}
+ return new Dimension (xSize, ySize);
+ }
+
+
+ /**
+ * Create a new image by rotating and scaling the given one
+ * @param inImage input image
+ * @param inMaxWidth maximum width of output image
+ * @param inMaxHeight maximum height of output image
+ * @param inRotationDegrees number of degrees to rotate clockwise (0, 90, 180 or 270)
+ * @return rotated, scaled image
+ */
+ public static BufferedImage rotateImage(Image inImage, int inMaxWidth, int inMaxHeight, int inRotationDegrees)
+ {
+ // Create scaled image of suitable size
+ boolean isRotated = (inRotationDegrees % 180 != 0);
+ int origWidth = inImage.getWidth(null);
+ int origHeight = inImage.getHeight(null);
+ int thumbWidth = isRotated?origHeight:origWidth;
+ int thumbHeight = isRotated?origWidth:origHeight;
+ Dimension scaledSize = getThumbnailSize(thumbWidth, thumbHeight, inMaxWidth, inMaxHeight);
+ BufferedImage result = new BufferedImage(scaledSize.width, scaledSize.height, BufferedImage.TYPE_INT_RGB);
+ // Do different things according to rotation angle (a bit messy, sorry!)
+ if (inRotationDegrees == 0)
+ {
+ // Not rotated, so just copy image directly
+ result.getGraphics().drawImage(inImage, 0, 0, scaledSize.width, scaledSize.height, null);
+ }
+ else
+ {
+ // Need to use Graphics2D for rotation, not Graphics
+ Graphics2D g2d = result.createGraphics();
+ switch (inRotationDegrees)
+ {
+ case 90:
+ g2d.rotate(Math.PI / 2, 0.0, 0.0);
+ g2d.drawImage(inImage, 0, -scaledSize.width, scaledSize.height, scaledSize.width, null);
+ break;
+ case 180:
+ g2d.rotate(Math.PI, scaledSize.width/2.0, scaledSize.height/2.0);
+ g2d.drawImage(inImage, 0, 0, scaledSize.width, scaledSize.height, null);
+ break;
+ case 270:
+ g2d.rotate(Math.PI * 3/2, 0.0, 0.0);
+ g2d.drawImage(inImage, -scaledSize.height, 0, scaledSize.height, scaledSize.width, null);
+ }
+ // Clear up memory
+ g2d.dispose();
+ }
+ return result;
+ }
+}
projects / GpsPrune.git / blobdiff