Java BufferedImage to Gray Scale imageToGrayscale(BufferedImage image)

Description

image To Grayscale

License

Open Source License

Declaration

public static BufferedImage imageToGrayscale(BufferedImage image) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;

public class Main {
    private static final ColorConvertOp RGB_TO_GRAYSCALE = new ColorConvertOp(
            ColorSpace.getInstance(ColorSpace.CS_sRGB),
            ColorSpace.getInstance(ColorSpace.CS_GRAY), null);

    public static BufferedImage imageToGrayscale(BufferedImage image) {
        final BufferedImage grayscale;

        // return the buffered image as-is, if it is binary already
        if (image.getType() == BufferedImage.TYPE_BYTE_BINARY) {
            return image;
        } else if (image.getType() == BufferedImage.TYPE_BYTE_GRAY) {
            grayscale = image;//w w w  . j  av a  2  s .co m
        } else if (image.getType() == BufferedImage.TYPE_INT_RGB
                || image.getType() == BufferedImage.TYPE_BYTE_INDEXED) {
            grayscale = new BufferedImage(image.getWidth(),
                    image.getHeight(), BufferedImage.TYPE_BYTE_GRAY);

            // convert rgb image to grayscale
            RGB_TO_GRAYSCALE.filter(image, grayscale);
        } else {
            throw new IllegalArgumentException(String.format(
                    "illegal color space: %s", image.getColorModel()
                            .getColorSpace().getType()));
        }

        return grayscale;
    }
}

Related

1. imageToGrayscale(BufferedImage img)
2. gray(BufferedImage src)
3. grayImage(BufferedImage image)
4. byteBufferToGrayBufferedImage(ByteBuffer buffer, BufferedImage bi)