Based on work found on Visual C# Kicks: http://www.vcskicks.com/fast-image-processing.php

FastBitmap is a bitmap wrapper class that intends to provide fast bitmap read/write operations on top of a safe layer of abstraction.

It provides operations for setting/getting pixel colors, copying regions accross bitmaps, clearing whole bitmaps, and copying whole bitmaps.

Editing pixels of a bitmap is just as easy as:

    Bitmap bitmap = new Bitmap(64, 64);
    
    using(var fastBitmap = bitmap.FastLock())
    {
        // Do your changes here...
        fastBitmap.Clear(Color.White);
        fastBitmap.SetPixel(1, 1, Color.Red);
    }

Or alternatively, albeit longer:

    Bitmap bitmap = new Bitmap(64, 64);
    FastBitmap fastBitmap = new FastBitmap(bitmap);
    
    // Locking bitmap before doing operations
    fastBitmap.Lock();
    
    // Do your changes here...
    fastBitmap.Clear(Color.White);
    fastBitmap.SetPixel(1, 1, Color.Red);
    
    // Don't forget to unlock!
    fastBitmap.Unlock();

This project contains the FastBitmap class and acompanying unit test suite.
Note that to compile this class you must have the /unsafe compiler flag turned on in your project settings.

Note: This code currently only works with 32bpp bitmaps

FastBitmap is available as a Nuget package:

PM > Install-Package FastBitmapLib

The following profiling tests showcase comparisions with the native System.Drawing.Bitmap equivalent method calls

SetPixel profiling
1024 x 1024 Bitmap SetPixel: 2054ms
1024 x 1024 FastBitmap SetPixel: 398ms
1024 x 1024 FastBitmap Int SetPixel: 331ms

Results: FastBitmap 6,21x faster

GetPixel profiling
1024 x 1024 Bitmap GetPixel: 1498ms
1024 x 1024 FastBitmap GetPixel: 382ms
1024 x 1024 FastBitmap Int GetPixel: 327ms

Results: FastBitmap 4,58x faster

Bitmap copying profiling
1024 x 1024 Bitmap SetPixel: 2888ms
1024 x 1024 FastBitmap CopyPixels: 5ms

Results: FastBitmap 577,60x faster

Bitmap clearing profiling
1024 x 1024 Bitmap SetPixel: 1795ms
1024 x 1024 FastBitmap Clear: 5ms

Results: FastBitmap 359,00x faster