Android Open Source - nfc-reader-app Image Manipulation

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License

The source code is released under:

Copyright (c) 2014, University of Washington All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions...

Java Source Code

package com.example.nfc_eink_demo;
//from  w w w  .j  ava  2  s .com
//import java.io.File;
//import java.io.FileOutputStream;
//import java.nio.ShortBuffer;

import android.graphics.Bitmap;
import android.graphics.Color;
import android.graphics.Matrix;


public class ImageManipulation {
  


  /**
   * Rotate the provided bitmap by the given number of degrees (in CW or CCW direction?)
   * @param src The original bitmap
   * @param degree The number of degrees by which to rotate
   * @return A rotated version of the original bitmap
   */
  public static Bitmap rotate(Bitmap src, float degree) {

    // Create new matrix
    Matrix matrix = new Matrix();
    // setup rotation degree
    matrix.postRotate(degree);

    // return the new bitmap
    return Bitmap.createBitmap(src, 0, 0, src.getWidth(), src.getHeight(),
        matrix, true);
  }// end rotate

  /**
   * Scale a bitmap to the given height and width
   * @param src The original bitmap
   * @param newHeight The new height
   * @param newWidth The new width
   * @return The scaled bitmap
   */
  public static Bitmap getResizedBitmap(Bitmap src, int newHeight, int newWidth) {
    int width = src.getWidth();
    int height = src.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // CREATE A MATRIX FOR THE MANIPULATION
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);

    // Generate scaled bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
        matrix, false);
    
    return resizedBitmap;
  }

  /**
   * Create a black and white version of the given bitmap
   * @param src The original bitmap
   * @return Black and white bitmap
   */
  public static Bitmap createBlackAndWhite(Bitmap src) {
    int width = src.getWidth();
    int height = src.getHeight();
    // create output bitmap
    Bitmap bmOut = Bitmap.createBitmap(width, height, src.getConfig());
    // color information
    int A, R, G, B;
    int pixel;

    // scan through all pixels
    for (int x = 0; x < width; ++x) {
      for (int y = 0; y < height; ++y) {
        // get pixel color
        pixel = src.getPixel(x, y);
        A = Color.alpha(pixel);
        R = Color.red(pixel);
        G = Color.green(pixel);
        B = Color.blue(pixel);
        
        int gray = (int) (0.2989 * R + 0.5870 * G + 0.1140 * B);

        // use 128 as threshold, above -> white, below -> black
        if (gray > 128)
          gray = 255;
        else
          gray = 0;
        // set new pixel color to output bitmap
        bmOut.setPixel(x, y, Color.argb(A, gray, gray, gray));
      }
    }
    return bmOut;
  }// end create black and white

  
//  static String saveBitmap(Bitmap bitmap, String dir, String baseName) {
//  try {
//    // File sdcard = Environment.getExternalStorageDirectory();
//    File pictureDir = new File("/sdcard/hello");
//    pictureDir.mkdirs();
//    File f = null;
//    for (int i = 1; i < 200; ++i) {
//      String name = baseName + i + ".png";
//      f = new File(pictureDir, name);
//      if (!f.exists()) {
//        break;
//      }
//    }
//    if (!f.exists()) {
//      String name = f.getAbsolutePath();
//      FileOutputStream fos = new FileOutputStream(name);
//      bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
//      fos.flush();
//      fos.close();
//      return name;
//    }
//  } catch (Exception e) {
//  } finally {
//    /*
//     * if (fos != null) { fos.close(); }
//     */
//  }
//  return null;
//}
//
//static void bitmapBGRtoRGB(Bitmap bitmap, int width, int height) {
//  int size = width * height;
//  short data[] = new short[size];
//  ShortBuffer buf = ShortBuffer.wrap(data);
//  bitmap.copyPixelsToBuffer(buf);
//  for (int i = 0; i < size; ++i) {
//    // BGR-565 to RGB-565
//    short v = data[i];
//    data[i] = (short) (((v & 0x1f) << 11) | (v & 0x7e0) | ((v & 0xf800) >> 11));
//  }
//  buf.rewind();
//  bitmap.copyPixelsFromBuffer(buf);
//}
  
};

Java Source Code List

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