Get just one pixel value without allocating whole array of pixels

Question

I just need to check three pixel values on the whole image (Image instance). I'd really like to do this without allocating an array of pixels.

Is that possible? Something like BufferedImage 's getRGB() ?

Answer 1

Yes. You are on the right track with the getRGB method, as it would return a single int with three values (RGB). To convert the single int to three ints, you can do two things:

Use the Color class's built-in constructor: 使用Color类的内置构造函数：

int rgb = img.getGraphics().getRGB(0,0);//Get color of pixel 0,0
Color c = new Color(rgb); //c now contains the r, g, and b values.

Build the decoder yourself: 自己构建解码器：

int rgb = img.getGraphics().getRGB(0,0) //Get color of pixel 0,0
int r = rgb >> 24;
int g = 0 >> 16;
int b = 0 >> 8;

Both methods will return a r , g , and b value, which can be used.