Java RGB Color Convert To RGB2YCbCr(int r, int g, int b, boolean useBT601)

Description

Convert RGB color info to YCBCr

License

Apache License

Parameter

Parameter	Description
r	8 bit red component
g	8 bit green component
b	8 bit blue component

Return

Integer array with luminance (Y), chrominance blue (Cb), chrominance red (Cr) (in this order)

Declaration

public static int[] RGB2YCbCr(int r, int g, int b, boolean useBT601) 

Method Source Code

//package com.java2s;
/*/*from   w  w w .  j  a v  a 2s  .co  m*/
 * Copyright 2012 Volker Oth (0xdeadbeef) / Miklos Juhasz (mjuhasz)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class Main {
    /**
     * Convert RGB color info to YCBCr
     * @param r 8 bit red component
     * @param g 8 bit green component
     * @param b 8 bit blue component
     * @return Integer array with luminance (Y), chrominance blue (Cb), chrominance red (Cr) (in this order)
     */
    public static int[] RGB2YCbCr(int r, int g, int b, boolean useBT601) {
        int[] yCbCr = new int[3];
        double y, cb, cr;

        if (useBT601) {
            /* BT.601 for RGB 0..255 (PC) -> YCbCr 16..235 */
            y = r * 0.299 * 219 / 255 + g * 0.587 * 219 / 255 + b * 0.114 * 219 / 255;
            cb = -r * 0.168736 * 224 / 255 - g * 0.331264 * 224 / 255 + b * 0.5 * 224 / 255;
            cr = r * 0.5 * 224 / 255 - g * 0.418688 * 224 / 255 - b * 0.081312 * 224 / 255;
        } else {
            /* BT.709 for RGB 0..255 (PC) -> YCbCr 16..235 */
            y = r * 0.2126 * 219 / 255 + g * 0.7152 * 219 / 255 + b * 0.0722 * 219 / 255;
            cb = -r * 0.2126 / 1.8556 * 224 / 255 - g * 0.7152 / 1.8556 * 224 / 255 + b * 0.5 * 224 / 255;
            cr = r * 0.5 * 224 / 255 - g * 0.7152 / 1.5748 * 224 / 255 - b * 0.0722 / 1.5748 * 224 / 255;
        }
        yCbCr[0] = 16 + (int) (y + 0.5);
        yCbCr[1] = 128 + (int) (cb + 0.5);
        yCbCr[2] = 128 + (int) (cr + 0.5);
        for (int i = 0; i < 3; i++) {
            if (yCbCr[i] < 16) {
                yCbCr[i] = 16;
            } else {
                if (i == 0) {
                    if (yCbCr[i] > 235)
                        yCbCr[i] = 235;
                } else {
                    if (yCbCr[i] > 240)
                        yCbCr[i] = 240;
                }
            }
        }
        return yCbCr;
    }
}

Related

1. rgb2intval(int r, int g, int b)
2. rgb2lab(int R, int G, int B)
3. rgb2luv(double[] rgb, double[] luv)
4. rgb2xyz(double[] RGB)
5. rgb2xyz(double[] rgb, double[] xyz)
6. RGB2YCbCr(int[] rgb, float[][] Y, float[][] Cb, float[][] Cr, int imageWidth, int imageHeight)
7. rgb2yuv(float r, float g, float b, float[] yuv)
8. rgb565ToRGB(short pixel, byte[] rgb)
9. rgb8ToPixel(byte[] nrgb)