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我正在尝试构建简单的 android 项目以将图像转换为二进制格式，但是当我检查像素值时，我只得到零。我不知道问题出在哪里。任何人都可以帮助我。这是我的代码

iv = (ImageView) findViewById (R.id.uploadImage);

//convert the image view into bitmap
iv.buildDrawingCache();
bmap = iv.getDrawingCache();

int red;
int newPixel = 0;
int threshold =230;
int width = bmap.getWidth();
int hieght = bmap.getHeight();
int[] pix = new int[width * hieght];
int[] pix2 = new int[width * hieght];
int alpha = 0;

bmap.getPixels(pix, 0, width, 0, 0, width, hieght);

//convert the image into white and black
for (int i=0;i<width;i++) {  
  for (int j=0;j<hieght;j++) {
    int index = j * width + i;

    red = (pix[index] >> 16) & 0xff;
    alpha = (pix[index] >> 24) & 0xff;

    if (red<threshold) {
      newPixel = 0;
    } else {
      newPixel = 255;
    }
    newPixel = colorToRGB(alpha, newPixel, newPixel, newPixel);
    bmap.setPixel(i, j, newPixel);
    iv.setImageBitmap(bmap);     
  }
} 

//convert the black and white image view into bitmap                                    
bmap.getPixels(pix2, 0, bmap.getWidth(), 0, 0, bmap.getWidth(),bmap.getHeight());

StringBuilder builder = new StringBuilder();
for (int i :pix2) {
  builder.append("   " + i + "    ");
}
Toast.makeText(this, builder, Toast.LENGTH_LONG).show();

private static int colorToRGB (int alpha, int red, int green, int blue) {
  int newPixel = 0;
  newPixel += alpha;
  newPixel = newPixel << 8;
  newPixel += red; newPixel = newPixel << 8;
  newPixel += green; newPixel = newPixel << 8;
  newPixel += blue;
  return newPixel;
}

这是日志猫

08-12 08:52:32.887: D/dalvikvm(774): GC_CONCURRENT freed 71K, 7% free 2765K/2964K, paused 23ms+15ms,总共94ms

08-12 08:52:33.497：D/gralloc_goldfish(774)：没有检测到 GPU 仿真的仿真器。

08-12 08:52:40.698: D/dalvikvm(774): GC_CONCURRENT freed 63K, 6% free 3087K/3272K, paused 73ms+3ms,总共165ms

08-12 08:52:49.397：I/Choreographer(774)：跳过 39 帧！应用程序可能在其主线程上做了太多工作。

08-12 08:52:54.568: D/dalvikvm(774): GC_FOR_ALLOC 释放 9K，5% 释放 3124K/3272K，暂停 68ms，总共 81ms

08-12 08:52:54.617: I/dalvikvm-heap(774): 将堆（碎片情况）增加到 6.166MB，分配 3145744 字节

08-12 08:52:54.778: D/dalvikvm(774): GC_FOR_ALLOC 释放 40K，4% 释放 6155K/6348K，暂停 156ms，总共 156ms

08-12 08:52:55.008: D/dalvikvm(774): GC_CONCURRENT freed <1K, 4% free 6155K/6348K, paused 80ms+38ms, total 231ms

08-12 08:52:55.898: I/Choreographer(774): 跳过 412 帧！应用程序可能在其主线程上做了太多工作。

08-12 08:52:57.898: D/dalvikvm(774): GC_FOR_ALLOC 释放 38K，4% 释放 6119K/6348K，暂停 28ms，共 30ms

08-12 08:52:57.929: I/dalvikvm-heap(774): 将堆（碎片情况）增加到 9.091MB，分配 3145744 字节

08-12 08:52:58.058: D/dalvikvm(774): GC_CONCURRENT freed <1K, 3% free 9191K/9424K, paused 82ms+6ms,总共125ms

08-12 08:52:58.058: D/dalvikvm(774): WAIT_FOR_CONCURRENT_GC 阻塞 40ms

08-12 08:52:58.089: I/dalvikvm-heap(774): 将堆（碎片情况）增加到 12.090MB，分配 3145744 字节

08-12 08:52:58.218: D/dalvikvm(774): GC_FOR_ALLOC 释放 <1K, 2% free 12263K/12500K, 暂停 125ms, 总共 126ms

08-12 08:52:58.288: D/dalvikvm(774): GC_CONCURRENT freed 0K, 2% free 12263K/12500K, paused 4ms+16ms,总共70ms

08-12 08:56:37.707: E/Trace(886): 打开跟踪文件时出错: 没有这样的文件或目录 (2) 08-12 08:56:38.518: D/dalvikvm(886): GC_CONCURRENT 释放 41K, 6 % free 2805K/2968K，暂停13ms+3ms，共77ms

08-12 08:56:38.518: D/dalvikvm(886): WAIT_FOR_CONCURRENT_GC 阻塞 10 毫秒

08-12 08:56:38.727：D/gralloc_goldfish(886)：没有检测到 GPU 仿真的仿真器。

08-12 08:56:55.107: D/dalvikvm(886): GC_FOR_ALLOC 释放 23K，5% 释放 3083K/3236K，暂停 69ms，总共 78ms

08-12 08:56:55.207: I/dalvikvm-heap(886): 将堆（碎片情况）增加到 6.126MB，分配 3145744 字节

08-12 08:56:55.367: D/dalvikvm(886): GC_FOR_ALLOC 释放 1K，3% 释放 6153K/6312K，暂停 156ms，总共 156ms

08-12 08:56:55.607: D/dalvikvm(886): GC_CONCURRENT freed 4K, 3% free 6149K/6312K, paused 80ms+32ms,总共245ms

08-12 08:56:56.747: I/Choreographer(886): 跳过 465 帧！应用程序可能在其主线程上做了太多工作。

08-12 08:58:03.287: D/dalvikvm(936): GC_CONCURRENT freed 44K, 6% free 2805K/2972K, paused 15ms+3ms,总共76ms

08-12 08:58:03.287: D/dalvikvm(936): WAIT_FOR_CONCURRENT_GC 阻塞 9ms

08-12 08:58:03.637: D/gralloc_goldfish(936): 没有检测到 GPU 仿真的仿真器。

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1 回答 1

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可能是因为您要转换的位图是零字节：

//convert the image view into bitmap
            iv.buildDrawingCache();
            bmap = iv.getDrawingCache();

尝试这个：

BitmapDrawable bd = (BitmapDrawable) iv.getDrawable();
            bmap = bd.getBitmap();

希望这可以帮助。

于 2013-08-12T08:44:45.477 回答