使用 Color Matrix 进行 sRGB 灰度转换

Question

灰度转换的 sRGB 因子为 B、G、R = 0.0722、0.7152、0.2126。 https://en.wikipedia.org/wiki/Grayscale

能否在具有 ColorMatrix 的 Format24bppRgb 图像上完成此灰度转换（如果可以，如何）？或者这只能以像素方式完成吗？

Answer 1

我还不太确定，但也许这就是答案：

Public Function ConvertToGrayscale(ByVal image As Bitmap) As Bitmap

    Dim grayscaleImage As Image = New Bitmap(image.Width, image.Height, PixelFormat.Format24bppRgb)
    Dim attributes As ImageAttributes = New System.Drawing.Imaging.ImageAttributes()

    Dim d1 As Double = 0.0722
    Dim d2 As Double = 0.7152
    Dim d3 As Double = 0.2126

    Dim grayscaleMatrix As New ColorMatrix(New Single()() {New Single() {d1, d1, d1, 0, 0}, New Single() {d2, d2, d2, 0, 0}, New Single() {d3, d3, d3, 0, 0}, New Single() {0, 0, 0, 1, 0}, New Single() {0, 0, 0, 0, 1}})
    attributes.SetColorMatrix(grayscaleMatrix)
    Using g As Graphics = Graphics.FromImage(grayscaleImage)
        g.DrawImage(image, New Rectangle(0, 0, grayscaleImage.Width, grayscaleImage.Height), 0, 0, grayscaleImage.Width, grayscaleImage.Height, GraphicsUnit.Pixel, attributes)
    End Using

    Return grayscaleImage

End Function

使用 Color Matrix 进行 sRGB 灰度转换

Using ColorMatrix for sRGB greyscale conversion

.net

image-processing

colormatrix

system.drawing.imaging