Convert bitmap from color to GrayScale

Convert bitmap from color to GrayScale

Last article described how to Convert bitmap from color to black and white using the simple formula BW = (R + G +)/3. Some experts suggested that it should be 0.3R + 0.59G + 0.11B ~ refer http://en.wikipedia.org/wiki/Grayscale.

Copy your test picture to /res/drawable folder, name it testpicture.jpg.

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76

package com.AndroidBitmapProcessing;   import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Color; import android.os.Bundle; import android.widget.ImageView;   public class AndroidBitmapProcessingActivity extends Activity {     ImageView imageView_Source, imageView_Gray, imageView_BW;  Bitmap bitmap_Source, bitmap_Dest;        /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);         imageView_Source = (ImageView)findViewById(R.id.source);         imageView_Gray = (ImageView)findViewById(R.id.imageGray);         imageView_BW = (ImageView)findViewById(R.id.imageBW);                   bitmap_Source = BitmapFactory.decodeResource(getResources(), R.drawable.testpicture);         imageView_Gray.setImageBitmap(processingBitmap_Gray(bitmap_Source));         imageView_BW.setImageBitmap(processingBitmap_BW(bitmap_Source));     }           private Bitmap processingBitmap_Gray(Bitmap src){             Bitmap dest = Bitmap.createBitmap(        src.getWidth(), src.getHeight(), src.getConfig());             for(int x = 0; x < src.getWidth(); x++){       for(int y = 0; y < src.getHeight(); y++){        int pixelColor = src.getPixel(x, y);        int pixelAlpha = Color.alpha(pixelColor);        float pixelRed = (float)Color.red(pixelColor) * 0.3f;        float pixelGreen = (float)Color.green(pixelColor) * 0.59f;        float pixelBlue = (float)Color.blue(pixelColor) * 0.11f;                 int pixelBW = (int)(pixelRed + pixelGreen + pixelBlue);        int newPixel = Color.argb(          pixelAlpha, pixelBW, pixelBW, pixelBW);                 dest.setPixel(x, y, newPixel);       }      }             return dest;     }           private Bitmap processingBitmap_BW(Bitmap src){             Bitmap dest = Bitmap.createBitmap(        src.getWidth(), src.getHeight(), src.getConfig());             for(int x = 0; x < src.getWidth(); x++){       for(int y = 0; y < src.getHeight(); y++){        int pixelColor = src.getPixel(x, y);        int pixelAlpha = Color.alpha(pixelColor);        int pixelRed = Color.red(pixelColor);        int pixelGreen = Color.green(pixelColor);        int pixelBlue = Color.blue(pixelColor);                 int pixelBW = (pixelRed + pixelGreen + pixelBlue)/3;        int newPixel = Color.argb(          pixelAlpha, pixelBW, pixelBW, pixelBW);                 dest.setPixel(x, y, newPixel);       }      }             return dest;     } } akm www.cdacians.com