Uploaded February 2014 | Updated September 2026, 2 weeks ago
This tutorial is about programming the Box Blur algorithm, in C++ or any other language. The video contains a general description of the double pass box blur algorithm, and is intended as a general tutorial on this common, and useful image affect.
The presents a diagram, or example using a spread sheet to explore and explain an example of the sliding window box blur algorithm.
The box blur algorithm is a special case of the Gaussian blur. It is a specific matrix version of the Gaussian blur.
Support What's a Creel? on Patreon:
patreon.com/whatsacreel
FaceBook:
facebook.com/whatsacreel
Music Channel:
youtube.com/channel/UC2nWRGqPL6O-Lm8mexWhISQ
Another channel with random things:
youtube.com/channel/UCK7bPumWNzWRnb3N8LCzKsA
The technique is to perform two passes of the image. During the first pass we perform a horizontal motion blur. During the second pass, we calculate a vertical motion blur on the output from the horizontal blur. The end result is the box blur but we've saved a massive amount of calculation. We no longer need to repeatedly sum the pixels in a small box over and over, instead, we can very quickly pass through the whole image calculating the much simpler horizontal and vertical motion blurs.
The algorithm doesn't actually appear on Wikipedia's Box Blur as I stated in the tute, you can find an excellent description here:
blog.amritamaz.me/post/42203030076/understanding-box-blur
This tutorial is about programming the Box Blur algorithm, in C++ or any other language. The video contains a general description of the double pass box blur algorithm, and is intended as a general tutorial on this common, and useful image affect.
The presents a diagram, or example using a spread sheet to explore and explain an example of the sliding window box blur algorithm.
The box blur algorithm is a special case of the Gaussian blur. It is a specific matrix version of the Gaussian blur.
Support What's a Creel? on Patreon:
patreon.com/whatsacreel
FaceBook:
facebook.com/whatsacreel
Music Channel:
youtube.com/channel/UC2nWRGqPL6O-Lm8mexWhISQ
Another channel with random things:
youtube.com/channel/UCK7bPumWNzWRnb3N8LCzKsA
The technique is to perform two passes of the image. During the first pass we perform a horizontal motion blur. During the second pass, we calculate a vertical motion blur on the output from the horizontal blur. The end result is the box blur but we've saved a massive amount of calculation. We no longer need to repeatedly sum the pixels in a small box over and over, instead, we can very quickly pass through the whole image calculating the much simpler horizontal and vertical motion blurs.
The algorithm doesn't actually appear on Wikipedia's Box Blur as I stated in the tute, you can find an excellent description here:
blog.amritamaz.me/post/42203030076/understanding-box-blur
