Android开发实现去除bitmap无用白色边框的方法示例

import android.graphics.Bitmap;
/**
 * Created by Victor Yang on 2016/6/17.
 * 去除 bitmap 无用的白色边框
 */
public class BitmapDeleteNoUseSpaceUtil {
  /**
   * 灰度化 bitmap
   * @param imgTheWidth
   * @param imgTheHeight
   * @param imgThePixels
   * @return
   */
  private static Bitmap getGrayImg(int imgTheWidth, int imgTheHeight, int[] imgThePixels) {
    int alpha = 0xFF <<24; //设置透明度
    for (int i = 0; i > 16); //获取红色灰度值
        int green = ((grey & 0x0000FF00) >> 8); //获取绿色灰度值
        int blue = (grey & 0x000000FF);     //获取蓝色灰度值
        grey = (int) ((float) red * 0.3 + (float) green * 0.59 + (float) blue * 0.11);
        grey = alpha | (grey <<16) | (grey <<8) | grey; //添加透明度
        imgThePixels[imgTheWidth * i + j] = grey;  //更改像素色值
      }
    }
    Bitmap result =
        Bitmap.createBitmap(imgTheWidth, imgTheHeight, Bitmap.Config.RGB_565);
    result.setPixels(imgThePixels, 0, imgTheWidth, 0, 0, imgTheWidth, imgTheHeight);
    return result;
  }
  /**
   * 去除多余白框
   * @param originBitmap
   * @return
   */
  public static Bitmap deleteNoUseWhiteSpace(Bitmap originBitmap) {
    int[] imgThePixels = new int[originBitmap.getWidth() * originBitmap.getHeight()];
    originBitmap.getPixels(
        imgThePixels,
        0,
        originBitmap.getWidth(),
        0,
        0,
        originBitmap.getWidth(),
        originBitmap.getHeight());
    // 灰度化 bitmap
    Bitmap bitmap = getGrayImg(
        originBitmap.getWidth(),
        originBitmap.getHeight(),
        imgThePixels);
    int top = 0; // 上边框白色高度
    int left = 0; // 左边框白色高度
    int right = 0; // 右边框白色高度
    int bottom = 0; // 底边框白色高度
    for (int h = 0; h = 0; w--) {
      boolean holdBlackPix = false;
      for (int h = 0; h = 0; h--) {
      boolean holdBlackPix = false;
      for (int w = 0; w