鼠标单击时GetPixel（x，y）上的颜色值不正确 [英] Incorrect color values on GetPixel(x,y) on Mouse Click

问题描述

我正试图从我在pictureBox上显示的图像中提取鼠标点击颜色。图片大于pictureBox，因此必须调整大小，并且分辨率为72 dpi，24位深度。关于图片属性（它是用iPhone拍摄的）它还说分辨率单元2和颜色表示sRGB。



我不确定它是否因为这个高分辨率，但是，无论是使用GetPixel还是锁定的图像数组，我总是得到错误的RGB值，鼠标点击位置。



图片中的鼠标点击事件：

Hi,
I'm trying to extract the mouse click color from a image that I display on a pictureBox. The picture is larger than the pictureBox, so has to be resized, and has a resolution on 72 dpi, 24 bit depth. On the picture properties (it was taken with an iPhone) it also says Resolution Unit 2 and Color Representation sRGB.

I'm not sure if its because of this high resolution, but, either working with GetPixel or a locked image array, I always get wrong RGB values for the mouse click position.

Inside the image mouse click event:

Dim args As System.Windows.Forms.MouseEventArgs = DirectCast(e, System.Windows.Forms.MouseEventArgs)
Dim clkX As Integer = args.X
Dim clkY As Integer = args.Y
lblColor_R.Text = bmpPiece.GetPixel(clkX, clkY).R
lblColor_G.Text = bmpPiece.GetPixel(clkX, clkY).G
lblColor_B.Text = bmpPiece.GetPixel(clkX, clkY).B

（bmpPiece以前声明为pieceBMP =新位图（pieceImagePath））



我使用了普通RGB托盘提供的RGB值，它们与屏幕上的图片完全不同



另外，我试着画一个小的提取颜色的图像，它完全不同：

（imgColor是PictureBox容器）

(bmpPiece is declared previous as pieceBMP = New Bitmap(pieceImagePath) )

I used the RGB values provided against a normal RGB pallet and they are quite different from the picture on the screen

Also, I try to paint a small image with the extracted color, and it's completely different:
(imgColor is the PictureBox container)

Dim pixelBrush As New SolidBrush(bmpPiece.GetPixel(clkX, clkY))
Dim newImage As New Bitmap(imgColor.Width, imgColor.Height)
Dim grap As Drawing.Graphics = Drawing.Graphics.FromImage(newImage)
grap.FillRectangle(pixelBrush, 0, 0, imgColor.Width, imgColor.Height)
imgColor.Image = newImage

有没有办法让这个提取像素颜色的工作？



非常感谢任何正确方向的指针，

Pedro

Is there any way to make this extraction of a pixel color to work?

thanks a lot for any pointer in the right direction,
Pedro

推荐答案

我为你构建了一个方法，它在PictureBox中获取PixelColor并反转其值（用于查看发生的情况）。

我的图像被分配给BackGroundImage，BackgroundImageLayout设置为Stretch。



我希望，此代码片段可以帮助您：

I build you a method which gets the PixelColor inside a PictureBox and inverts in's value (for seeing what happens).
My Image was assigned to BackGroundImage with the BackgroundImageLayout set to Stretch.

I hope, this code-snippet will help you :

Private Sub PictureBox1_Click(sender As System.Object, e As MouseEventArgs) Handles PictureBox1.MouseClick
    Dim clkX As Integer = e.X
    Dim clkY As Integer = e.Y

    Dim gr As Graphics = Graphics.FromImage(PictureBox1.BackgroundImage)
    Dim myBitmap As New Bitmap(PictureBox1.BackgroundImage, PictureBox1.Size)

    Dim clkColor As Color = myBitmap.GetPixel(clkX, clkY)
    Dim newColor = Color.FromArgb(255 - clkColor.R, 255 - clkColor.G, 255 - clkColor.B) ' set Pixel inverted
    myBitmap.SetPixel(clkX, clkY, newColor)

    PictureBox1.BackgroundImage = myBitmap

End Sub

您好Ralf，

感谢您的建议。我会尝试并回复。有它来自图像本身的回调，我承认我从未想过它需要X / Y转换。

私有子imgPiece_Click（发送者作为对象，e作为EventArgs）处理imgPiece.Click



谢谢，

Pedro

Hi Ralf,
thank you for the suggestion. I'll try it and post back. Has its the callback from the image itself, I confess I never thought it would need X/Y transformation.
Private Sub imgPiece_Click(sender As Object, e As EventArgs) Handles imgPiece.Click

thanks,
Pedro

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