Changing an ImageView to black and white

You can simply achieve this by doing:

ImageView imageview = (ImageView) findViewById(R.id.imageView1);
ColorMatrix matrix = new ColorMatrix();
matrix.setSaturation(0);

ColorMatrixColorFilter filter = new ColorMatrixColorFilter(matrix);
imageview.setColorFilter(filter);

This is the Kotlin Version

imageView.colorFilter = ColorMatrixColorFilter(ColorMatrix().apply { setSaturation(0f)})

You can use android.graphics.ColorFilter for your purpose.

You can use this sample to suite your need. Pass the imageView to the setBW method like

setBW(imageView);

and the the functionality is

private void setBW(ImageView iv){

     float brightness = 10; // change values to suite your need

     float[] colorMatrix = { 
             0.33f, 0.33f, 0.33f, 0, brightness,
             0.33f, 0.33f, 0.33f, 0, brightness, 
             0.33f, 0.33f, 0.33f, 0, brightness,
             0, 0, 0, 1, 0    
           };

     ColorFilter colorFilter = new ColorMatrixColorFilter(colorMatrix);
        iv.setColorFilter(colorFilter);
    }

Try using this. Any concerns. Let me know. Thanks.

I would also suggest using Kotlin extensions:

private const val MAX_SATURATION = 1f
private const val MIN_SATURATION = 0f

fun ImageView.setMaxSaturation() {
    val matrix = ColorMatrix()
    matrix.setSaturation(MAX_SATURATION)

    colorFilter = ColorMatrixColorFilter(matrix)
}

fun ImageView.setMinSaturation() {
    val matrix = ColorMatrix()
    matrix.setSaturation(MIN_SATURATION)

    colorFilter = ColorMatrixColorFilter(matrix)
}