#
# lab9extra5.py (Lab 9, Extra-practice exercise 5)
#
# Computer Science 111
# 

from hmcpng import *

def create_uniform_image(height, width, pixel):
    """ creates and returns a 2-D list of pixels with height rows and
        width columns in which all of the pixels have the RGB values
        given by pixel
        inputs: height and width are non-negative integers
                pixel is a list of RBG values of the form [R,G,B],
                     where each element is an integer between 0 and 255.
    """
    pixels = []
    
    for r in range(height):
        row = [pixel] * width
        pixels += [row]

    return pixels
            
def remove_blue(pixels):
    """ takes the specified 2-D list of pixels (where each pixel is
        a list of the form [R,G,B]) and creates and returns a new 
        2-D list of pixels in which the blue component of each pixel
        is set to 0.
        input: pixel is a rectangular 2-D list of pixels
    """
    height = len(pixels)
    width = len(pixels[0])

    # Create a 2-D list that we'll use for the new image. 
    # We start with a uniform image filled with green pixels, 
    # but then we'll replace the green pixels with ones that 
    # represent the pixels of the original image with blue removed.
    new_pixels = create_uniform_image(height, width, [0, 255, 0])
    
    for r in range(height):
        for c in range(width):
            # Get the original pixel at row r, column c.
            pixel = pixels[r][c]

            # Create a new pixel in which the red and green components
            # are the same as in the original pixel, but the blue is removed,
            # and assign it to the appropriate location in new_pixels.
            new_pixels[r][c] = [pixel[0], pixel[1], 0]

    return new_pixels