InJustice47 - 8 months ago 69

Java Question

When i want to check if two Bufferedimages are the same, i can simply compare them pixel by pixel using these two loops:

`boolean bufferedImagesEqual(BufferedImage img1, BufferedImage img2) {`

if (img1.getWidth() == img2.getWidth() && img1.getHeight() == img2.getHeight()) {

for (int x = 0; x < img1.getWidth(); x++) {

for (int y = 0; y < img1.getHeight(); y++) {

if (img1.getRGB(x, y) != img2.getRGB(x, y))

return false;

}

}

} else {

return false;

}

return true;

}

I took this from : Here

But I also want this to work if

`img2`

`90 or 270`

`x`

`y`

`img2.getWidth()-x`

in the second

`.getRGB()`

I know it may not be the hardest problem in the world but i cannot seem to figure it out.

Any help would be greatly appreciated.

Answer

I think it is unavoidable to perform the "2-loops" 3 times: one for 0 degree rotation, the second 90 and the third 270:

For 90 degrees: (assert img1.getWidth()==img2.getHeight() && img1.getHeight()==img2.getWidth())

```
for (int x = 0; x < img1.getWidth(); x++) {
for (int y = 0; y < img1.getHeight(); y++) {
if (img1.getRGB(x, y) != img2.getRGB(img1.getHeight() - 1 - y, x))
return false;
}
}
```

For 270 degrees: (assert img1.getWidth()==img2.getHeight() && img1.getHeight()==img2.getWidth())

```
for (int x = 0; x < img1.getWidth(); x++) {
for (int y = 0; y < img1.getHeight(); y++) {
if (img1.getRGB(x, y) != img2.getRGB(y, img1.getWidth() - 1 - x))
return false;
}
}
```