如何在Windows Phone 8中将普通图像转换为灰度图像?在WritableBitmapEx中是否有提供灰度转换的功能?
如何在Windows Phone 8中将普通图像转换为灰度图像?在WritableBitmapEx中是否有提供灰度转换的功能?
try this extension method...
public static WriteableBitmap ToGrayScale(this WriteableBitmap bitmapImage)
{
for (var y = 0; y < bitmapImage.PixelHeight; y++)
{
for (var x = 0; x < bitmapImage.PixelWidth; x++)
{
var pixelLocation = bitmapImage.PixelWidth * y + x;
var pixel = bitmapImage.Pixels[pixelLocation];
var pixelbytes = BitConverter.GetBytes(pixel);
var bwPixel = (byte)(.299 * pixelbytes[2] + .587 * pixelbytes[1] + .114 * pixelbytes[0]);
pixelbytes[0] = bwPixel;
pixelbytes[1] = bwPixel;
pixelbytes[2] = bwPixel;
bitmapImage.Pixels[pixelLocation] = BitConverter.ToInt32(pixelbytes, 0);
}
}
return bitmapImage;
}
我认为没有一个现成的方法,但是你可以自己转换。有很多在线资源可以帮助你完成这个过程。首先阅读这篇文章。其中一种更简单的方法可能是:
for (int i = 0; i < oldBitmap.Pixels.Length; i++)
{
var c = oldBitmap.Pixels[i];
var a = (byte)(c >> 24);
var r = (byte)(c >> 16);
var g = (byte)(c >> 8);
var b = (byte)(c);
byte gray = (byte)((r * 0.3) + (g * 0.59) + (b * 0.11));
oldBitmap.Pixels[i] = (a << 24) | (gray << 16) | (gray << 8) | gray;
}
这很简单、快速,而且你可以原地进行转换。