Image Processing in C#: A Comprehensive Guide

C# is a great language to do image processing in. It's fast and easy to handle complex image manipulations with it.

In order to process an image in C# you need to take the following steps:

• Load an Image File in C#
• Process the image (see below)
• Save the Image to a file as either PNG or JPG

We will walk you through each of these steps, as well as show you how to do a few common image processing tasks like color replacement, contrast adjustment, negative image, and brightness adjustment.

If you followed our guide above title Load an Image File in C# then you should have an image file loaded as a Bitmap object and have it locked. If not, please follow that guide first. Once a image is loaded in RAM you can easily process it by iterating over the Height and Width looking at 1 pixel at a time. You can use GetPixel to get the color of a pixel and SetPixel to set the color of a pixel. Here's an example of replacing all Black pixels with White pixels.

var lockedBitmap = new LockBitmap(bmp);
lockedBitmap.LockBits();

for (int y = 0; y < lockedBitmap.Height; y++)
{
    for (int x = 0; x < lockedBitmap.Width; x++)
    {
        if (lockedBitmap.GetPixel(x, y) == Color.Black)
        {
            lockedBitmap.SetPixel(x, y, Color.White);
        }
    }
}

Now you are ready to start writing Image editing functions. Here are a few that we have shared.

• Replace a Color in an Image with C#
• Convert an Image to Gray Scale in C#
• How to Lighten an Image in C#
• How to Darken an Image in C#
• Adjust the Contrast of an Image in C#
• Scale an Image in C# Preserving Aspect Ratio