Question

用于灰度转换的sRGB因子是B，G，R = 0.0722,0.7152,0.2126。 https://en.wikipedia.org/wiki/Grayscale

可以使用ColorMatrix在Format24bppRgb图像上完成此灰度转换（如果是，如何）？或者这只能按像素完成吗？

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ColorMatrix进行sRGB灰度转换

1 个答案: