Change Image Pixel color to Redor any other in Windows Phone 8

Question

I am new to Windows Phone * development,in my project I need to convert the pixel of image to either Red,Green,Violet,etc colors as per my requirements.Can anyone send a sample code to do this process?

It would be a great help.

Thanks.

Answer 1

See my solution here for converting an image to gray scale.

Convert A Dynamic Bitmap To Gray Scale.

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Play attention to the loop where I decode each Red,Green,Blue pixel out of the Pixel array and where I reassemble the picture back with Buffer.BlockCopy. So basically you can do whatever you want with those components to modify your picture then BlockCopy it back.

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private void PutPixel(int x, int y, byte red, byte green, byte blue, ref WriteableBitmap wb)
{
    if(wb == null)
        return;
    int[] PixelsBuffer = new int[1];
    unchecked
    {
        PixelsBuffer[0] = (int)( 0xFF000000 | (int)red << 16 | (int)green << 8 | blue);
    }
    int offset = ((y * wb.PixelWidth) + x) * 4;
    Buffer.BlockCopy(PixelsBuffer, 0, wb.Pixels, offset, 4);            
}

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Code In Action

<Image x:Name="myImage" Source="/Assets/AlignmentGrid.png" Stretch="None" />

// draw a white line from (0,0) to (100, 100)    
private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
    WriteableBitmap wb = new WriteableBitmap((BitmapImage)this.myImage.Source);
    for (int i = 0; i < 100; i++)
    {
        PutPixel(i, i, 0xFF, 0xFF, 0xFF, ref wb);
    }
    myImage.Source = wb;
}

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