Get color of each pixel of an image using BufferedImages

Question

I am trying to get every single color of every single pixel of an image. My idea was following:

int[] pixels; BufferedImage image;  image = ImageIO.read(this.getClass.getResources("image.png"); int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData(); 

Is that right? I can't even check what the "pixels" array contains, because i get following error:

java.awt.image.DataBufferByte cannot be cast to java.awt.image.DataBufferInt 

I just would like to receive the color of every pixel in an array, how do i achieve that?

Answer 1

import java.io.*; import java.awt.*; import javax.imageio.ImageIO; import java.awt.image.BufferedImage;  public class GetPixelColor {     public static void main(String args[]) throws IOException {         File file = new File("your_file.jpg");         BufferedImage image = ImageIO.read(file);         // Getting pixel color by position x and y          int clr = image.getRGB(x, y);         int red =   (clr & 0x00ff0000) >> 16;         int green = (clr & 0x0000ff00) >> 8;         int blue =   clr & 0x000000ff;         System.out.println("Red Color value = " + red);         System.out.println("Green Color value = " + green);         System.out.println("Blue Color value = " + blue);     } } 

of course you have to add a for loop for all pixels

Answer 2

The problem (also with the answer that was linked from the first answer) is that you hardly ever know what exact type your buffered image will be after reading it with ImageIO. It could contain a DataBufferByte or a DataBufferInt. You may deduce it in some cases via BufferedImage#getType(), but in the worst case, it has type TYPE_CUSTOM, and then you can only fall back to some instanceof tests.

However, you can convert your image into a BufferedImage that is guaranteed to have a DataBufferInt with ARGB values - namely with something like

public static BufferedImage convertToARGB(BufferedImage image) {     BufferedImage newImage = new BufferedImage(         image.getWidth(), image.getHeight(),         BufferedImage.TYPE_INT_ARGB);     Graphics2D g = newImage.createGraphics();     g.drawImage(image, 0, 0, null);     g.dispose();     return newImage; } 

Otherwise, you can call image.getRGB(x,y), which may perform the required conversions on the fly.

BTW: Note that obtaining the data buffer of a BufferedImage may degrade painting performance, because the image can no longer be "managed" and kept in VRAM internally.