android - 将 Android 上使用 ML Kit 进行自拍分割的分割结果保存为具有透明背景的位图

Question

Android端ML Kit自拍分割结果保存为背景透明的Bitmap

我正在按照本教程和代码进行自拍分割

Here

我从教程中引用了这段代码

ByteBuffer mask = segmentationMask.getBuffer();
int maskWidth = segmentationMask.getWidth();
int maskHeight = segmentationMask.getHeight();

for (int y = 0; y < maskHeight; y++) {
  for (int x = 0; x < maskWidth; x++) {
    // Gets the confidence of the (x,y) pixel in the mask being in the foreground.
    float foregroundConfidence = mask.getFloat();
  }
}

生成掩码

然后我引用了生成紫色背景 mask 的示例应用

Here

使用这段代码

@ColorInt
  private int[] maskColorsFromByteBuffer(ByteBuffer byteBuffer) {
    @ColorInt int[] colors = new int[maskWidth * maskHeight];
    for (int i = 0; i < maskWidth * maskHeight; i++) {
      float backgroundLikelihood = 1 - byteBuffer.getFloat();
      if (backgroundLikelihood > 0.9) {
        colors[i] = Color.argb(128, 255, 0, 255);
      } else if (backgroundLikelihood > 0.2) {
        // Linear interpolation to make sure when backgroundLikelihood is 0.2, the alpha is 0 and
        // when backgroundLikelihood is 0.9, the alpha is 128.
        // +0.5 to round the float value to the nearest int.
        int alpha = (int) (182.9 * backgroundLikelihood - 36.6 + 0.5);
        colors[i] = Color.argb(alpha, 255, 0, 255);
      }
    }
    return colors;
  }

现在我想用检测到的原始图像生成一个图像蒙版并将其覆盖在透明图像上并为此保存该位图我正在使用此代码

 public Bitmap generateMaskBgImage(Bitmap image, Bitmap bg) {
//Bg is Transparent Png Image.
            Bitmap bgBitmap = Bitmap.createBitmap(image.getWidth(), image.getHeight(), image.getConfig());
            for (int y = 0; y < maskHeight; y++) {
                for (int x = 0; x < maskWidth; x++) {
                    int bgConfidence = (int) ((1.0 - maskBuffer.getFloat()) * 255);
                    int bgPixel = bg.getPixel(x, y);
                    bgPixel = ColorUtils.setAlphaComponent(bgPixel, bgConfidence);
                    bgBitmap.setPixel(x, y, bgPixel);
                }
            }
            maskBuffer.rewind();
            return bitmapUtils.mergeBitmaps(image, bgBitmap);
        }

然而，它会生成一个具有所需蒙版但背景为黑色的图像，我们如何才能将该图像保存为透明背景。

Answer 1

你可以试试这个(color1 是你在 mask 中设置的颜色):

private Bitmap performBW(Bitmap originBitmap,Bitmap maskBitmap) {
    Bitmap bmOut = Bitmap.createBitmap(originBitmap.getWidth(), originBitmap.getHeight(),
            originBitmap.getConfig());
    int w = originBitmap.getWidth();
    int h = originBitmap.getHeight();
    int[] colors = new int[w * h];
    int[] colorsMask=new int[maskBitmap.getWidth() * maskBitmap.getHeight()];

    originBitmap.getPixels(colors, 0, w, 0, 0, w, h);
    maskBitmap.getPixels(colorsMask, 0, w, 0, 0, w, h);

    int pos;

    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            pos = i * w + j;

            if (colorsMask[pos] == color1) colors[pos]=Color.TRANSPARENT; 
        }
    }
    bmOut.setPixels(colors, 0, w, 0, 0, w, h);
    return bmOut;
}