I am trying to change the values from a gray scale PNG image and then create an image from those changed values.
The first step I took was using a python implementation of libpng. With that I was able to get a list of all the pixel values of the PNG. It is a gray scale image so the values where from 0 to 100. I do a quick algorithm to change the values. And then I try to create it into a new PNG file. Its all on a single line so I use regex to format it into a 2D array.
I attempted to use this that I found here
from PIL import Image
import numpy as np
pixels = [[100,0,0],[0,100,0],[0,0,100]]
# Convert the pixels into an array using numpy
array = np.array(pixels)
print(array)
# Use PIL to create an image from the new array of pixels
new_image = Image.fromarray(array, 'L')
new_image.save('testing.png')
But I guess the formatting that PIL uses is different from what the libpng is so instead of making an image that looks like 3 white pixels diagonally, I only get 1 white pixel on the top left. So either I change the values I am getting from libpng so that numpy works, or I find something in libpng that will allow me to change the values directly and create the new file.
The error in your code is that you are not setting the right data type for the array. If you call array = np.array(pixels, dtype='uint8') then your code will work.