cordova-plugin-sketch在多次编辑时失去了质量

Question

我正在使用cordova-plugin-sketch插件，而我在Android上遇到问题，每次渲染/保存时图像的质量都会下降。其中一位维护者已经足够好提供一些链接来帮助解决问题，但到目前为止我还没有成功。我对Android开发相当新，这是问题的一部分。

插件： https://github.com/blinkmobile/cordova-plugin-sketch

问题： https://github.com/blinkmobile/cordova-plugin-sketch/issues/3

我已尝试在inDensity上设置inTargetDensity和BitmapFactory.Options的不同选项，但未找到任何可提高质量的设置。此外，我想这些设置的有效性会根据使用的设备而改变。

正在修改的文件：TouchDrawActivity.java

我尝试过改变：

mBitmap = createScaledBitmap(mBitmap, mTdView.mCanvas.getWidth(),
            mTdView.mCanvas.getHeight(),ScalingLogic.FIT);
//mBitmap = Bitmap.createScaledBitmap(mTdView.mCanvas.getWidth(),mTdView.mCanvas.getHeight(),false);

现在使用此代码：

public static Bitmap createScaledBitmap(Bitmap unscaledBitmap, int dstWidth, int dstHeight, ScalingLogic scalingLogic)
{
    Rect srcRect = calculateSrcRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(), dstWidth, dstHeight, scalingLogic);
    Rect dstRect = calculateDstRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(), dstWidth, dstHeight, scalingLogic);
    Bitmap scaledBitmap = Bitmap.createBitmap(dstRect.width(), dstRect.height(), Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(scaledBitmap);
    canvas.drawBitmap(unscaledBitmap, srcRect, dstRect, new Paint(Paint.FILTER_BITMAP_FLAG));

    return scaledBitmap;
}

public static Rect calculateSrcRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight, ScalingLogic scalingLogic)
{
    if (scalingLogic == ScalingLogic.CROP)
    {
        final float srcAspect = (float) srcWidth / (float) srcHeight;
        final float dstAspect = (float) dstWidth / (float) dstHeight;

        if (srcAspect > dstAspect)
        {
            final int srcRectWidth = (int) (srcHeight * dstAspect);
            final int srcRectLeft = (srcWidth - srcRectWidth) / 2;
            return new Rect(srcRectLeft, 0, srcRectLeft + srcRectWidth, srcHeight);
        }
        else
        {
            final int srcRectHeight = (int) (srcWidth / dstAspect);
            final int scrRectTop = (int) (srcHeight - srcRectHeight) / 2;
            return new Rect(0, scrRectTop, srcWidth, scrRectTop + srcRectHeight);
        }
    }
    else
    {
        return new Rect(0, 0, srcWidth, srcHeight);
    }
}

public static Rect calculateDstRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight, ScalingLogic scalingLogic)
{
    if (scalingLogic == ScalingLogic.FIT)
    {
        final float srcAspect = (float) srcWidth / (float) srcHeight;
        final float dstAspect = (float) dstWidth / (float) dstHeight;

        if (srcAspect > dstAspect)
        {
            return new Rect(0, 0, dstWidth, (int) (dstWidth / srcAspect));
        }
        else
        {
            return new Rect(0, 0, (int) (dstHeight * srcAspect), dstHeight);
        }
    }
    else
    {
        return new Rect(0, 0, dstWidth, dstHeight);
    }
}

不幸的是，图像质量下降似乎几乎不相同。