Video processing

Reto Vogel — Sat, 14 Nov 2009 13:05:03 +0000

This post is all about video. I created a small video recorder and a tiny app which tracks brightness and a specific color.

Video recorder

For this simple video recorder, I took the animation from a previous exercise (confetti) and added a record an replay function. The programm makes a mov-File of the animation. The record starts by pressing ‘R’ and stops after pressing ‘S’. After recording the file can be played/paused by pressing ‘P’.

Click here to watch a recorded sample file.

Since the execution doesn’t work within the browser you can download the source code (pde-file) here.

Brightness tracking

The program two functions. Either recognize the brightest point in the webcam image or following a indivual definable color. This can easily be done by clicking somewhere inside the image. Then every pixel gets compared with the choosen color. If there’s a similarity, the pixel is going to be considered as a part of the object.

By pressing UP or DOWN the tolerance value changes. Pressing the right mouse button resets the picked color and the brightest point is overlayed (yellow circle).

Try it out! You can view the source file to compile (unfortunately it does not work within the browser).

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Pixel editing with Processing

Reto Vogel — Sat, 31 Oct 2009 13:11:37 +0000

According to Wikipedia, “Image editing” encompasses the processes of altering images, whether they be digital photographs, traditional analog photographs, or illustrations. Images are stored in a computer in the form of a grid of picture elements, or pixels. These pixels contain the image’s color and brightness information.

In our case, we altered digital photos and learned mor about how to manipulate pixels and techniques to overlay several images.

Image manipulation

I created several pixel manipulations with Processing.

You can see the result in this applet.

Pixel Image

The tasks was about creating a “pixeling” effect. This can be achieved by several ways. I created a grid and took the very first point of each box. Then I filled the rest of the box with the first pixel’s color.

The pixel-resolution can be adjusted whithin the applet by pressing UP and DOWN.

Threshold

In order to get a pure black-and-white picture, you need to set a threshold. The threshold value determines, where the border between black and white is.

You can try it on your own with my applet. Press UP or DOWN to increase or decreasae the resolution and LEFT or RIGHT to change the threshold.

Overlay Images

This applet shows how to overlay two different images. The source are two pictures with the same size. You get different results by adding, subtracting or multiplying.

Check out the applet here.