Here you can find the source of toGrayscale(Bitmap bmpOriginal, int pixels)
public static Bitmap toGrayscale(Bitmap bmpOriginal, int pixels)
//package com.java2s; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.Canvas; import android.graphics.ColorMatrix; import android.graphics.ColorMatrixColorFilter; import android.graphics.Paint; import android.graphics.PorterDuff.Mode; import android.graphics.PorterDuffXfermode; import android.graphics.Rect; import android.graphics.RectF; import android.graphics.drawable.BitmapDrawable; public class Main { public static Bitmap toGrayscale(Bitmap bmpOriginal) { int width, height; height = bmpOriginal.getHeight(); width = bmpOriginal.getWidth();// w ww . j a v a 2 s .c om Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); Canvas c = new Canvas(bmpGrayscale); Paint paint = new Paint(); ColorMatrix cm = new ColorMatrix(); cm.setSaturation(0); ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm); paint.setColorFilter(f); c.drawBitmap(bmpOriginal, 0, 0, paint); return bmpGrayscale; } public static Bitmap toGrayscale(Bitmap bmpOriginal, int pixels) { return toRoundCorner(toGrayscale(bmpOriginal), pixels); } public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) { Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888); Canvas canvas = new Canvas(output); final int color = 0xff424242; final Paint paint = new Paint(); final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); final RectF rectF = new RectF(rect); final float roundPx = pixels; paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); paint.setColor(color); canvas.drawRoundRect(rectF, roundPx, roundPx, paint); paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); return output; } public static BitmapDrawable toRoundCorner( BitmapDrawable bitmapDrawable, int pixels) { Bitmap bitmap = bitmapDrawable.getBitmap(); bitmapDrawable = new BitmapDrawable(toRoundCorner(bitmap, pixels)); return bitmapDrawable; } }