Comparing video pixel array, frame by frame.

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mytx

Comparing video pixel array, frame by frame.

in General Discussion • Other • 10 months ago

Hello!
First of all, this is my first post and I'm a total amateur in Processing.

I have a very simple video of a white background and a black silhouette walking from left to right. 180 frames total.
What I need to do is to compare pixel array of one frame to the next one, and get data about:
- How many pixels are black and how many are white (getting only one of these two amounts will make the job)
- How many more/less black pixels than in the previous frame?
- Witch pixels are still in the same position as previous frame?

Could I analyse this in video or I must do it frame by frame as pictures?

Any help or observation is appreciated, I will be resolving this all weekend

Cheers!

Replies(1)

asimes

Re: Comparing video pixel array, frame by frame.

10 months ago

I have never done that as a video, but it quite straightforward to do as a series of images. Just name all of the images sequentially (myImage0, myImage1, myImage2, etc) and put them in a folder named "data" inside your sketch folder. Set up some code to go from one image to another whenever your image analysis is complete or whenever the user (you) presses a button. Maybe something as simple as:

- LEFT means previous image (unless current image is 0)

- RIGHT means next image (unless current image is last image)

- DOWN could mean compare with previous image (unless current image is 0)

- UP could mean compare with next image (unless current image is last image)

Counting the number of pixels that are pure white or pure black is simple, but be careful because it is common that a pixel is almost black or almost white so you will want some kind of margin of error.

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