How do I create a BufferedImage from array containing pixels?

Question

I get the pixels from BufferedImage using the method getRGB(). The pixels are stored in array called data[]. After some manipulation on data array, I need to create a BufferedImage again so that I can pass it to a module which will display the modified image, from this data array, but I am stuck with it.

score 26 · Answer 1 · answered Feb 22 '12 at 14:13

26

I get the pixels from the BufferedImage using the method getRGB(). The pixels are stored in array called data[].

Note that this can possibly be terribly slow. If your BufferedImage supports it, you may want to instead access the underlying int[] and directly copy/read the pixels from there.

For example, to fastly copy your data[] into the underlying int[] of a new BufferedImage:

BufferedImage bi = new BufferedImage( w, h, BufferedImage.TYPE_INT_ARGB );
final int[] a = ( (DataBufferInt) res.getRaster().getDataBuffer() ).getData();
System.arraycopy(data, 0, a, 0, data.length);

Of course you want to make sure that your data[] contains pixels in the same representation as your BufferedImage (ARGB in this example).

answered Feb 22 '12 at 14:13

TacticalCoder

6,275
3
31
39

1

This is the better answer. I can't think of any situation in which setRGB is an optimal solution for anything. – man guy Oct 31 '17 at 07:48
3

I think there's a mistake in your code: do you mean `bi.getRaster` instead of `res.getRaster`? – RDM Jan 26 '18 at 16:16
@manguy I don't think their answer works, I tried it. I think it is because they made an array using the BufferedImage data, but the array doesn't actually point to the BufferedImage. It is just a new reference that was created. – Some Guy Jan 30 '22 at 02:27

epoch · Accepted Answer · 2017-12-07T20:46:19.343

0

BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

Then set the pixels again.

bufferedImage.setRGB(x, y, your_value);

_{PS: as stated in the comments, please use the answer from @TacticalCoder}

edited Dec 07 '17 at 20:46

answered Feb 22 '12 at 14:08

epoch

16,396
4
43
71

2

You shouldn't loop through a whole image and set one bit at a time. You should copy the whole buffer in one go. – Yochai Timmer Dec 09 '14 at 11:50
2

this is a terrible way to set all the pixels in a bufferedimage and should not be the accepted answer. – user_4685247 Oct 29 '15 at 17:48

score -1 · Answer 3 · answered Feb 22 '12 at 14:02

-1

You can set the RGB (int) values for the pixels in the new image using the setRGB methods.

answered Feb 22 '12 at 14:02

cdc

2,511
2
17
15

how do i create the bufferedimage?? – Saurabh Feb 22 '12 at 14:04

How do I create a BufferedImage from array containing pixels?

3 Answers3

Linked