Java's ImageIO can't process 4-component images and Java2D can't apply AffineTransformOp either, so convert raster data to RGB. - Java 2D Graphics

Java examples for 2D Graphics:BufferedImage Convert

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Description

Java's ImageIO can't process 4-component images and Java2D can't apply AffineTransformOp either, so convert raster data to RGB.

Demo Code


//package com.java2s;

import java.awt.Transparency;
import java.awt.color.ColorSpace;

import java.awt.image.BufferedImage;

import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;

import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;

import java.awt.image.Raster;

import java.awt.image.WritableRaster;

public class Main {
    /**                                                                                                                                           
    Java's ImageIO can't process 4-component images                                                                                             
    and Java2D can't apply AffineTransformOp either,                                                                                            
    so convert raster data to RGB.                                                                                                              
    Technique due to MArk Stephens.                                                                                                             
    Free for any use.                                                                                                                           
     *//* ww w .j  av  a  2 s  .com*/
    private static BufferedImage createJPEG4(Raster raster) {
        int w = raster.getWidth();
        int h = raster.getHeight();
        byte[] rgb = new byte[w * h * 3];

        float[] Y = raster.getSamples(0, 0, w, h, 0, (float[]) null);
        float[] Cb = raster.getSamples(0, 0, w, h, 1, (float[]) null);
        float[] Cr = raster.getSamples(0, 0, w, h, 2, (float[]) null);
        float[] K = raster.getSamples(0, 0, w, h, 3, (float[]) null);

        for (int i = 0, imax = Y.length, base = 0; i < imax; i++, base += 3) {
            float k = 220 - K[i], y = 255 - Y[i], cb = 255 - Cb[i], cr = 255 - Cr[i];

            double val = y + 1.402 * (cr - 128) - k;
            val = (val - 128) * .65f + 128;
            rgb[base] = val < 0.0 ? (byte) 0 : val > 255.0 ? (byte) 0xff
                    : (byte) (val + 0.5);

            val = y - 0.34414 * (cb - 128) - 0.71414 * (cr - 128) - k;
            val = (val - 128) * .65f + 128;
            rgb[base + 1] = val < 0.0 ? (byte) 0
                    : val > 255.0 ? (byte) 0xff : (byte) (val + 0.5);

            val = y + 1.772 * (cb - 128) - k;
            val = (val - 128) * .65f + 128;
            rgb[base + 2] = val < 0.0 ? (byte) 0
                    : val > 255.0 ? (byte) 0xff : (byte) (val + 0.5);
        }

        raster = Raster.createInterleavedRaster(new DataBufferByte(rgb,
                rgb.length), w, h, w * 3, 3, new int[] { 0, 1, 2 }, null);
        ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_sRGB);
        ColorModel cm = new ComponentColorModel(cs, false, true,
                Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
        return new BufferedImage(cm, (WritableRaster) raster, true, null);
    }
}

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