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;
*/
public static Dimension getThumbnailSize(int inOrigWidth, int inOrigHeight, int inMaxWidth, int inMaxHeight)
{
- if (inMaxWidth <= 0 || inMaxHeight <= 0)
- {
- //System.out.println("Can't do it - maxwidth=" + inMaxWidth + ", maxheight=" + inMaxHeight);
- return new Dimension(0,0);
- }
+ 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
- return new Dimension ((int) (zoom * inOrigWidth), (int) (zoom * inOrigHeight));
+ 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;
}
}