Incorrect colors when reconstructing an image from arrays with pygame/pyglet

Question

I wrote up this program that would use numpy and Image(PIL) library to read an image as a bunch of matrices and use pyglet(and opengl) to reconstruct the image.

The code using pyglet is as follows:

import Image
import numpy
import window
import sys
import pyglet
import random
a=numpy.asarray(Image.open(sys.argv[1]))
h,w= a.shape[0],a.shape[1]
s=a[0]
print s.shape

#######################################
def display():
    x_a=0;y_a=h
    for page in a:
        for array in page: 
            j=array[2]
            k=array[1]
            l=array[0]
            pyglet.gl.glColor3f(l,j,k)
            pyglet.gl.glVertex2i(x_a,y_a)
            x_a+=1
        y_a-=1  
        x_a=0
######################################33
def on_draw(self):
    global w,h

    self.clear
    pyglet.gl.glClear(pyglet.gl.GL_COLOR_BUFFER_BIT)
    pyglet.gl.glBegin(pyglet.gl.GL_POINTS)
    display()
    pyglet.gl.glEnd()
    pyglet.image.get_buffer_manager().get_color_buffer().save('screenshot.png')
window.win.on_draw=on_draw

#######################################

u=window.win(w,h)
pyglet.app.run()

The same code modified to use the pygame library (and which is devoid of any opengl usage)

import pygame
import numpy
import Image
import sys
from pygame import gfxdraw

color=(255,255,255)

a=numpy.asarray(Image.open(sys.argv[1]))
h,w=a.shape[0],a.shape[1]

pygame.init()
screen = pygame.display.set_mode((w,h))

def uu():
    y_a=0
    for page in a:
        x_a=0
        for array in page:
            co=(array[0],array[1],array[2])
            pygame.gfxdraw.pixel(screen,x_a,y_a,co)
            x_a+=1
        y_a+=1

uu()
done = False

while not done:
        for event in pygame.event.get():
                if event.type == pygame.QUIT:
                        done = True

        pygame.display.flip()

The result from pyglet vs. pygame:

So my question is...why is there a problem? Is there a problem with the way I utilised opengl to draw the picture pixel by pixel or there something else that is for now beyond my comprehension?

Answer 1

Pygame.Color expects integers in the range 0-255, while pyglet.gl.glColor3f expects floats in the range 0.0-1.0. A conversion like this should fix your problem:

j=array[0] / 255.0
k=array[1] / 255.0
l=array[2] / 255.0
pyglet.gl.glColor3f(j,k,l)