Save canvas image

[chrismoto]

Hello I need some help. How do I save images have been written (touch screen) to the screen with the stylus. I came across information regarding the canvas and using FileConnection API. I am yet to be able to put everything together however. Can someone please show me how to save the written image to the memory card.

Thanks,
CHris

[Tiger79]

maybe u can link to the mentioned information/articles so that someone can fill in the missing gaps ?

[raj_J2ME]

Hello I need some help. How do I save images have been written (touch screen) to the screen with the stylus. I came across information regarding the canvas and using FileConnection API. I am yet to be able to put everything together however. Can someone please show me how to save the written image to the memory card.

Thanks,
CHris

Hey,
Please forgive me if I understand your post wrongly.
Are you talking about like saving the signature kind of thing?

[Steel_BRS]

Hi Chris, I just use RAW format for my screenshot routine - it's crude but it works:

    public static void saveScreenDump(Image screenDump) {
        FileConnection conn = null;
        DataOutputStream dos = null;
        try {
            int[] screenDumpRGB = new int[screenDump.getWidth() * screenDump.getHeight()];
            screenDump.getRGB(screenDumpRGB, 0, screenDump.getWidth(), 0, 0, screenDump.getWidth(), screenDump.getHeight());

            String filename = "" + System.currentTimeMillis() + ".raw";
            String fileconn_dir = System.getProperty("fileconn.dir.photos");
            if (fileconn_dir == null || "".equals(fileconn_dir))
                fileconn_dir = "file:///c:/other/";     // Works K600i and P990i (extremely slow!)

            conn = (FileConnection) Connector.open(fileconn_dir + filename, Connector.READ_WRITE);

            if (!conn.exists())
                conn.create();
            dos = conn.openDataOutputStream();
            for(int i = 0; i < screenDumpRGB.length; i++)
                dos.writeInt(screenDumpRGB[i]);

            System.out.println("image saved");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (dos != null)
                    dos.close();
                if (conn != null)
                    conn.close();
            } catch (IOException e) {
                // Well ...
            }
        }
    }

I just did a quick search for a Java ME implementation of a PNG or JPEG encoder, but couldn't find one. But I remember this encoding has to be done manually - there's no function in JSR-135 MMAPI that encodes an Image for you.

Also this doesn't work on Motorola phones unless you have one of their developer certificates. No access to JSR-75 FileConnection API without a certificate.

Anyway the file is [width * height * 4] bytes.

To convert a RAW image to PNG in Java SE:

    if (rawFile.length() == 240 * 320 * 4) {
        int[] imageData = new int[240 * 320];
        for (int i = 0; i < imageData.length; i++)
            imageData[i] = dis.readInt();

        BufferedImage image = new BufferedImage(240, 320, BufferedImage.TYPE_INT_ARGB);
        image.setRGB(0, 0, 240, 320, imageData, 0, 240);
        ImageIO.write(image, "PNG", new File(rawFile.getAbsolutePath().replace(".raw", ".png")));
    }