Help to get a Byte array from Bitmap, GetPixel is too slow

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G

Guest

I am trying to get a Byte array out of a Bitmap that already exists. The
bitmap is in Format32bppArgb format. I am using the following code but it is
very slow.
Is there any other way to copy RGB values of a Bitmap into byte array?

b = new byte[ABitmap.Width*ABitmap.Height*3];
for(int y=0;y<ABitmap.Height;y++)
{
for(int x=0;x<ABitmap.Width;x++)
{
acolor=ABitmap.GetPixel(x,y);
b=acolor.R;
b[i+1]=acolor.G;
b[i+2]=acolor.B;
i=i+3;
}
}

I have searched a lot for an alternative solution and LockBits seems to be
the right way to do this but it is not working for some reason. I don't get
the right image.
This is what I am doing with LockBits.

Rectangle bounds= new Rectangle(0, 0, ABitmap.Width, ABitmap.Height);
BitmapData bitmapData = ABitmap.LockBits(bounds, ImageLockMode.ReadWrite,
PixelFormat.Format24bppRgb);
b = new byte[ABitmap.Height * bitmapData.Stride];
Marshal.Copy(bitmapData.Scan0, b, 0, ABitmap.Height * bitmapData.Stride);

I lose some pixels, the image gets stretched.

Is there any easyway to copy the RGB values of a Bitmap into byte array?

Please advise.

Kind Regards
Jim
 
Jim byrd said:
I am trying to get a Byte array out of a Bitmap that already exists. The
bitmap is in Format32bppArgb format. I am using the following code but it is
very slow.
Is there any other way to copy RGB values of a Bitmap into byte array?
Click to expand...

Have you tried saving it to a MemoryStream using ImageFormat.MemoryBmp?
I don't know much about the format myself, but it sounds useful...
 
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