I am new to numpy and I want to replace specefic elements in a 3D numpy array. My 3D numpy array represents an image. The shape of the array is: (1080, 1920, 3). The number 3 represents RGB of each pixel in the image.
All I want to know is how to change all the elements that are equal to [0,0,0] into [255,255,255] Which means i want all black pixels in the image to be white.. How can i do it? Thanks!
Say you have stored your array in data; this should work:
data[(data == 0).all(axis=2)] = [255, 255, 255]
This is due to numpy's broadcasting rules, which compare each value to 0, resulting in a boolean array with True values where they compare equal and False elsewhere.
The next step is to take only those sub-arrays where all of the individual values do compare equal, with .all(axis=2) - the last axis, which is the one you want.
Then, with the resulting boolean array, you can index back into data, which will give you only those sub-arrays equal to [0, 0, 0], and set those to [255, 255, 255].
