Android Realization of Image Grayscale Linear Grayscale Change and Binary Processing Method

1. Image grayscale:

public Bitmap bitmap2Gray(Bitmap bmSrc) { 
  //  Get the length and width of the picture  
  int width = bmSrc.getWidth(); 
  int height = bmSrc.getHeight(); 
  //  Create a gray image of the target  
  Bitmap bmpGray = null; 
  bmpGray = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565); 
  //  Create a canvas  
  Canvas c = new Canvas(bmpGray); 
  Paint paint = new Paint(); 
  ColorMatrix cm = new ColorMatrix(); 
  cm.setSaturation(0); 
  ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm); 
  paint.setColorFilter(f); 
  c.drawBitmap(bmSrc, 0, 0, paint); 
  return bmpGray; 
}

2. Carry out linear gray level change on the image

public Bitmap lineGrey(Bitmap image) {
  // Get the width and length of the image  
  int width = image.getWidth(); 
  int height = image.getHeight(); 
  // Create a linear pull-up grayscale image  
  Bitmap linegray = null; 
  linegray = image.copy(Config.ARGB_8888, true); 
  // The pixels of the image are processed cyclically in turn  
  for (int i = 0; i < width; i++) { 
    for (int j = 0; j < height; j++) { 
      // Get the pixel value of each point  
      int col = image.getPixel(i, j); 
      int alpha = col & 0xFF000000; 
      int red = (col & 0x00FF0000) >> 16; 
      int green = (col & 0x0000FF00) >> 8; 
      int blue = (col & 0x000000FF); 
      //  Increases the brightness of the image  
      red = (int) (1.1 * red + 30); 
      green = (int) (1.1 * green + 30); 
      blue = (int) (1.1 * blue + 30); 
      // Processing the image pixel out of bounds  
      if (red >= 255)  
      { 
        red = 255; 
      } 

      if (green >= 255) { 
        green = 255; 
      } 

      if (blue >= 255) { 
        blue = 255; 
      } 
      //  New ARGB 
      int newColor = alpha | (red << 16) | (green << 8) | blue; 
      // Set the for the new image RGB Value  
      linegray.setPixel(i, j, newColor); 
    } 
  } 
  return linegray; 
} 

3. Binary the image

public Bitmap gray2Binary(Bitmap graymap) { 
  // Get the width and length of the graph  
  int width = graymap.getWidth(); 
  int height = graymap.getHeight(); 
  // Create 2 Valuable image  
  Bitmap binarymap = null; 
  binarymap = graymap.copy(Config.ARGB_8888, true); 
  // The pixels of the image are processed in turn  
  for (int i = 0; i < width; i++) { 
    for (int j = 0; j < height; j++) { 
      // Get the value of the current pixel  
      int col = binarymap.getPixel(i, j); 
      // Get alpha The value of the channel  
      int alpha = col & 0xFF000000; 
      // Get the pixels of the image RGB Value of  
      int red = (col & 0x00FF0000) >> 16; 
      int green = (col & 0x0000FF00) >> 8; 
      int blue = (col & 0x000000FF); 
      //  With a formula X = 0.3 × R+0.59 × G+0.11 × B Calculate X Replace the original RGB 
      int gray = (int) ((float) red * 0.3 + (float) green * 0.59 + (float) blue * 0.11); 
      // Perform an image 2 Valuation processing  
      if (gray <= 95) { 
        gray = 0; 
      } else { 
        gray = 255; 
      } 
      //  New ARGB 
      int newColor = alpha | (gray << 16) | (gray << 8) | gray; 
      // Set the current pixel value of the new image  
      binarymap.setPixel(i, j, newColor); 
    } 
  } 
  return binarymap; 
}