How To Make The Color Image To Black And White In Android

I wanted to know the way to convert the color image (which i am downloading from net) to black and white when i am displaying it to the user in android. can anybody found this r

Solution 1:

Hi you can make the image black n white using contrast.

See the code..

publicstatic Bitmap createContrast(Bitmap src, double value) {
    // image sizeintwidth= src.getWidth();
    intheight= src.getHeight();
    // create output bitmapBitmapbmOut= Bitmap.createBitmap(width, height, src.getConfig());
    // color informationint A, R, G, B;
    int pixel;
    // get contrast valuedoublecontrast= Math.pow((100 + value) / 100, 2);

    // scan through all pixelsfor(intx=0; x < width; ++x) {
        for(inty=0; y < height; ++y) {
            // get pixel color
            pixel = src.getPixel(x, y);
            A = Color.alpha(pixel);
            // apply filter contrast for every channel R, G, B
            R = Color.red(pixel);
            R = (int)(((((R / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
            if(R < 0) { R = 0; }
            elseif(R > 255) { R = 255; }

            G = Color.red(pixel);
            G = (int)(((((G / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
            if(G < 0) { G = 0; }
            elseif(G > 255) { G = 255; }

            B = Color.red(pixel);
            B = (int)(((((B / 255.0) - 0.5) * contrast) + 0.5) * 255.0);
            if(B < 0) { B = 0; }
            elseif(B > 255) { B = 255; }

            // set new pixel color to output bitmap
            bmOut.setPixel(x, y, Color.argb(A, R, G, B));
        }
    }

    return bmOut;
}

Set the double value to 50 on mathod call. For Example createContrast(Bitmap src, 50)

Solution 2:

Use the built-in methods:

publicstatic Bitmap toGrayscale(Bitmap srcImage) {

    BitmapbmpGrayscale= Bitmap.createBitmap(srcImage.getWidth(), srcImage.getHeight(), Bitmap.Config.ARGB_8888);

    Canvascanvas=newCanvas(bmpGrayscale);
    Paintpaint=newPaint();

    ColorMatrixcm=newColorMatrix();
    cm.setSaturation(0);
    paint.setColorFilter(newColorMatrixColorFilter(cm));
    canvas.drawBitmap(srcImage, 0, 0, paint);

    return bmpGrayscale;
}