Method getPixel

ij/src/main/java/ij/ImagePlus.java:1810–1860

Returns the pixel value at (x,y) as a 4 element array. Grayscale values are retuned in the first element. RGB values are returned in the first 3 elements. For indexed color images, the RGB values are returned in the first 3 three elements and the index (0-255) is returned in the last.

(int x, int y)

	first 3 three elements and the index (0-255) is returned in the last.
	*/
	public int[] getPixel(int x, int y) {
		pvalue[0]=pvalue[1]=pvalue[2]=pvalue[3]=0;
		switch (imageType) {
			case GRAY8: case COLOR_256:
				int index;
				if (ip!=null)
					index = ip.getPixel(x, y);
				else {
					byte[] pixels8;
					if (img==null) return pvalue;
					PixelGrabber pg = new PixelGrabber(img,x,y,1,1,false);
					try {pg.grabPixels();}
					catch (InterruptedException e){return pvalue;};
					pixels8 = (byte[])(pg.getPixels());
					index = pixels8!=null?pixels8[0]&0xff:0;
				}
				if (imageType!=COLOR_256) {
					pvalue[0] = index;
					return pvalue;
				}
				pvalue[3] = index;
				// fall through to get rgb values
			case COLOR_RGB:
				if (ip!=null && ip.getNChannels()==1) {
					pvalue[0] = ip.getPixel(x, y);
					return pvalue;
				}
				int c = 0;
				if (imageType==COLOR_RGB && ip!=null)
					c = ip.getPixel(x, y);
				else {
					int[] pixels32 = new int[1];
					if (img==null) return pvalue;
					PixelGrabber pg = new PixelGrabber(img, x, y, 1, 1, pixels32, 0, width);
					try {pg.grabPixels();}
					catch (InterruptedException e) {return pvalue;};
					c = pixels32[0];
				}
				int r = (c&0xff0000)>>16;
				int g = (c&0xff00)>>8;
				int b = c&0xff;
				pvalue[0] = r;
				pvalue[1] = g;
				pvalue[2] = b;
				break;
			case GRAY16: case GRAY32:
				if (ip!=null) pvalue[0] = ip.getPixel(x, y);
				break;
		}
		return pvalue;
	}

	/** Returns an empty image stack that has the same
		width, height and color table as this image. */