Crop image by polygon area in Java

Question

by using Canvas and JS I can draw a shape like this and have the x,y of each point :

Tha area can be choosen by more than 4 points, look at this link to have an idea.

I need to save and crop the image of the selected area by using the points. I can not use BufferedImage as it is just rectangular. Which lib in java I can use?

Answer 1

Okay, so starting with...

I used...

BufferedImage source = ImageIO.read(new File("Example.jpg"));
GeneralPath clip = new GeneralPath();
clip.moveTo(65, 123);
clip.lineTo(241, 178);
clip.lineTo(268, 405);
clip.lineTo(145, 512);
clip.closePath();

Rectangle bounds = clip.getBounds();
BufferedImage img = new BufferedImage(bounds.width, bounds.height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
clip.transform(AffineTransform.getTranslateInstance(-65, -123));
g2d.setClip(clip);
g2d.translate(-65, -123);
g2d.drawImage(source, 0, 0, null);
g2d.dispose();

ImageIO.write(img, "png", new File("Clipped.png"));

to generate...

Now, the image is rectangular, that's just the way it works

Now, setClip is quite rough and isn't effect by any RenderingHints , you could make use of "soft clipping" instead, which is more involved, but generates a nicer results. See this example and this exmaple for more details