J2ME黑白图像采集

Question

我想使用 j2me 捕获黑白图像 我可以捕捉彩色图像，但想要捕捉黑白和灰度图像，

我在相机画布中的哪里设置此属性？

Answer 1

您很可能需要使用管理器的图像编码设置
http://java.sun.com /javame/reference/apis/jsr135/javax/microedition/media/Manager.html#media_encodings

Answer 2

通过使用以下代码，您可以将图像转换为灰度

import java.io.IOException;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Image;
import javax.microedition.midlet.MIDlet;

public class Grey extends MIDlet {
    private Form frm;

public void startApp() {
    if (frm == null) {
        frm = new Form("Grey");
        try {
            Image img = makeGreyScale(Image.createImage("/test.png"));
            frm.append(img);
        } catch (IOException e) {
            frm.append(e.toString());
        }
        Display.getDisplay(this).setCurrent(frm);
    }
}

public void pauseApp() {
    // do nothing
}

public void destroyApp(boolean b) {
    // do nothing
}

// here is where the action is...
private static Image makeGreyScale(Image img) {
    // work out how many pixels, and create array
    int width = img.getWidth();
    int height = img.getHeight();
    int[] pixels = new int[width * height];
    // get the pixel data
    img.getRGB(pixels, 0, width, 0, 0, width, height);
    // convert to grey scale
    for (int i = 0; i < pixels.length; i++) {
        // get one pixel
        int argb = pixels[i];
        // separate colour components
        int alpha = (argb >> 24) & 0xff;
        int red   = (argb >> 16) & 0xff;
        int green = (argb >>  8) & 0xff;
        int blue  =  argb        & 0xff;
        // construct grey value
        int grey = (((red * 30) / 100) + ((green * 59) / 100) + ((blue * 11) / 100)) & 0xff;
        // reconstruct pixel with grey value - keep original alpha
        argb = (alpha << 24) | (grey << 16) | (grey << 8) | grey;
        // put back in the pixel array
        pixels[i] = argb;
    }
    // create and return a new Image
    return Image.createRGBImage(pixels, width, height, true);
}

}