Creating noise images with Python and OpenGL

[Avatrin]

Hi

I am learning how to do a line integral convolution with OpenGL given a vector field. So, as a first step, I need to learn how to create an nxn noise image. Are there any good tutorials/books I can use to learn how to do this?

 

[jedishrfu]

Here's one way:

import random
n=3
nxn = [[random.random() for i in range(n)] for j in range(n)]

You can replace random.random() with an expression to magnify the random values as random.random() values vary from 0.0 to 1.0

so 5*randomrandom() will give you a spread of 0.0 to 5.0

and (5*randomrandom()+3) will give you a range of 3.0 to 8.0 as examples.

 

[Avatrin]

Alright, but this doesn't output an image. That's why I am asking for a tutorial or a book; I am not sure a forum post is going to tell me how to create images with OpenGL.

 

[jedishrfu]

Here's an example of converting an image to an array:

https://stackoverflow.com/questions/27026866/convert-an-image-to-2d-array-in-python

and the reverse is here:

https://stackoverflow.com/questions/2659312/how-do-i-convert-a-numpy-array-to-and-display-an-image

 

[Avatrin]

Here's an example of converting an image to an array:

https://stackoverflow.com/questions/27026866/convert-an-image-to-2d-array-in-python

and the reverse is here:

https://stackoverflow.com/questions/2659312/how-do-i-convert-a-numpy-array-to-and-display-an-image

Those clearly use pillow... I am specifically asking for how to do this with OpenGL.

 

[jedishrfu]

Last try, here’s an example using pillow and OpenGL:

https://stackoverflow.com/questions/41126090/how-to-write-pyopengl-in-to-jpg-image