Re: creating buffered image

From:

"John B. Matthews" <nospam@nospam.invalid>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 12 Nov 2010 06:41:45 -0500

Message-ID:

<nospam-338203.06414512112010@news.aioe.org>

In article
<fb21d6ac-7293-4625-8ad0-2b8cdd1ef372@z20g2000pra.googlegroups.com>,
mark jason <markjason72@gmail.com> wrote:

I am working on an image processing application and thought of
creating a class called FaceImage to represent a n image of a human
face. I created the class like this:

Please format code so that it remains readable, as suggested in the
article here: <http://sscce.org/>

I also wanted to implement a saveImage() method so that I can save
the FaceImage object as an image file of given format. However when I
tried MemoryImageSource constructor I found that it needs an int[]
not double[].

WritableRaster has accessors for int, float and double.

Is there some way I can use the double[] containing pixel to save a
new image? Do I need to convert the double[] to int[] as needed by
MemoryImageSource? I guess a for loop would be very inefficient.

I'd probably just use a BufferedImage; that way I can use ImageIO, as
suggested in the tutorial:

<http://download.oracle.com/javase/tutorial/2d/images/index.html>

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class FaceImage {

    private String fileName;
    private BufferedImage bi;
    private int w;
    private int h;
    double[] dData;
    int[] iData;

    public FaceImage(File imageFile) throws IOException {
        bi = ImageIO.read(imageFile);
        this.fileName = imageFile.getName();
        this.w = bi.getWidth();
        this.h = bi.getHeight();
        this.dData = bi.getData().getPixels(0, 0, w, h, dData);
        this.iData = bi.getData().getPixels(0, 0, w, h, iData);
    }

    public FaceImage(String fileName, int w, int h, double[] data) {
        if (data.length != 3 * w * h) {
            throw new IllegalArgumentException(
                "data size must be equal to " + w * h);
        }
        this.fileName = fileName;
        this.w = w;
        this.h = h;
        this.dData = data;
        this.bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        bi.getRaster().setPixels(0, 0, w, h, data);
        this.iData = bi.getData().getPixels(0, 0, w, h, iData);
    }

    public void save() throws IOException {
        ImageIO.write(bi, "JPEG", new File(fileName));
    }

    public static void main(String[] args) throws IOException {
        new FaceImage(new File("image.jpg"));
        new FaceImage("one.jpg", 1, 1, new double[]{0, 0, 0});
    }
}

Any help or advice would be nice.

--
John B. Matthews
trashgod at gmail dot com
<http://sites.google.com/site/drjohnbmatthews>

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