java image crop
I am aware of BufferedImage.getSubimage
However, it cant deal with cropping images that are smaller than the cropping size throwing the exception:
java.awt.image.RasterFormatEx开发者_JS百科ception: (y + height) is outside raster
I want to be able to crop either a PNG/JPG/GIF to a certain size however if the image is smaller than the cropping area centre itself on a white background. Is there a call to do this? Or do I need to create an image manually to centre the image on if so, how would I go about this?
Thanks
You cannot crop an image larger, only smaller. So, you start with the goal dimension,let's say 100x100. And your BufferedImage
(bi
), let's say 150x50.
Create a rectangle of your goal:
Rectangle goal = new Rectangle(100, 100);
Then intersect it with the dimensions of your image:
Rectangle clip = goal.intersection(new Rectangle(bi.getWidth(), bi.getHeight());
Now, clip corresponds to the portion of bi
that will fit within your goal. In this case 100 x50.
Now get the subImage
using the value of clip
.
BufferedImage clippedImg = bi.subImage(clip,1, clip.y, clip.width, clip.height);
Create a new BufferedImage
(bi2
), the size of goal
:
BufferedImage bi2 = new BufferedImage(goal.width, goal.height);
Fill it with white (or whatever bg color you choose):
Graphics2D big2 = bi2.getGraphics();
big2.setColor(Color.white);
big2.fillRect(0, 0, goal.width, goal.height);
and draw the clipped image onto it.
int x = goal.width - (clip.width / 2);
int y = goal.height - (clip.height / 2);
big2.drawImage(x, y, clippedImg, null);
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