Question

我想在Windows Phone 8.1中调整图像的对比度我找到了Windows Phone 7的示例，但它在Windows Phone 8.1中不起作用。

这是我的代码：

    public static WriteableBitmap ChangeContrast(WriteableBitmap Bitmap,
                                                    int[] orgPixels,
                                                    double contrastValue)
    {
        var result = new WriteableBitmap(Bitmap.PixelWidth, Bitmap.PixelHeight);
        var contrastFactor = (50f + contrastValue) / 50f;
        contrastFactor *= contrastFactor;
        var contrastFactorIndex = (int)(contrastFactor * 32768);
        var inputPixels = Bitmap.PixelBuffer;
        int[] tempPixels = new int[Bitmap.PixelBuffer.Length];
        orgPixels.CopyTo(tempPixels, 0);
        if (0 != Bitmap.PixelBuffer.Length)
        {
            for (int index = 0; index < Bitmap.PixelBuffer.Length; index++)
            {
                // Extract color components
                var color = tempPixels[index];
                var alpha = (byte)(color >> 24);
                var red = (byte)(color >> 16);
                var green = (byte)(color >> 8);
                var blue = (byte)(color);
                int ri = red - 128;
                int gi = green - 128;
                int bi = blue - 128;

                // Multiply contrast factor
                ri = (ri * contrastFactorIndex) >> 15;
                gi = (gi * contrastFactorIndex) >> 15;
                bi = (bi * contrastFactorIndex) >> 15;

                // Transform back to range [0, 255]
                ri = ri + 128;
                gi = gi + 128;
                bi = bi + 128;
                // Clamp to byte boundaries
                red = (byte)(ri > 255 ? 255 : (ri < 0 ? 0 : ri));
                green = (byte)(gi > 255 ? 255 : (gi < 0 ? 0 : gi));
                blue = (byte)(bi > 255 ? 255 : (bi < 0 ? 0 : bi));
                result.SetValue[index] = (alpha << 24) | (red << 16) | (green << 8) | blue;
            }
        }

//附加Buffer.BlockCopy（tempPixels，0，inputPixels，0，tempPixels.Length）;

        return result;
    }

＆＃39; SetValue＆＃39;是＆＃39;像素＆＃39;在原始样本中，但在WP8.1上此对象中不存在像素。

等同的是什么？

Answer 1

您想要修改int [] tempPixels数组。完成后，您需要将tempPixel数组复制回result.PixelBuffer。您可以使用Buffer.BlockCopy将块复制到另一个块。

完整示例：如何调整亮度：Adjust Brightness WriteableBitmap 8.1

完整示例：灰度图像：Grayscale an Image WriteableBitmap 8.0

请务必在System.IO和System.Runtime.InteropServices.WindowsRuntime中添加上述解决方案。

我还在OneDrive中包含了完整的8.1项目：Adjust Brightness Project 8.1

在Windows Phone 8.1中调整图像

1 个答案: