Hi,

I am writing code to Gray Scale an Image. For that I am doing loop on each pixel as shown in code below. It is working but time required to do this is very long compare to other Graphics Processing Programs.
Is there other fast way to do this?

...

...

I'm no grahics wiz, I'm sure there's a cool way to do this with GDI+, but at least you can start by getting rid of the floats, and move out the temp-allocations. I.e.:

Color c;
int luma;
for (int x = 0; x < m_Bitmap.Width; x++) 
{
    c = m_Bitmap.GetPixel(x, y); 
    luma = (c.R * 30 + c.G * 59 + c.B * 11)/100;
    m_Bitmap.SetPixel(x, y, Color.FromArgb(luma, luma, luma)); 
}

 You might also gain a bit by pre-generating the Color-structures (since you're doing Color.FromArg(luma, luma, luma) there are only 256 possible values). Create an array with 256 entires, and place ready-mady Color-structures there. Something like this:

// Do this first - outside both loops
Color[] colors = new Color[256];
for (int i = 0; i < colors.Length; i++)
{
    colors[i] = Color.FromArgb(i, i, i);
}

// then you can do...
m_Bitmap.SetPixel(x, y, colors[luma]);

Thanks. This makes sense and helpful.

But I am still looking for fast way. Please let me know if anybody have idea.

Solution is here

http://www.bobpowell.net/grayscale.htm

Hi,

 Its really great article, It helps me lot.

thanks buddy.