A script to map the luminance values of image pixels into three-dimensional space.

luminance-plot.py

from PIL import Image
import sys

def rgb2hex(r, g, b):
    return '#{:02x}{:02x}{:02x}'.format(r, g, b)

def printError(err):
    print(err)
    sys.exit(1)

try:
    img = Image.open(sys.argv[1]).convert('RGB')
except IndexError:
    printError('Error: No input file specified.\nUsage: python luminance-plot.py [input file] [output file] [striation interval]')
except IOError:
    printError('Error: Input file "{}" not found.'.format(sys.argv[1]))

try: sys.argv[2]
except IndexError:
    printError('Error: No output file specified.\nUsage: python luminance-plot.py [input file] [output file] [striation interval]')

try:
    striation = int(sys.argv[3])
except ValueError:
    printError('Error: Striation interval is not an integer.')
except IndexError:
    printError('Error: No striation interval specified.\nUsage: python luminance-plot.py [input file] [output file] [striation interval]')

with open(sys.argv[2], 'w') as f:
    for x in range(0, img.size[0]):
        for y in range(0, img.size[1]):
            r, g, b = img.getpixel((x, y))
            luminosity = int(((0.241 * r**2)+(0.691 * g**2)+(0.068 * b**2)) ** 0.5)

            for i in range(0, luminosity, striation):
                f.write('{},{},{}\n'.format(str(x*2), str(i), str(y*2)))
            f.write('{},{},{}\n'.format(str(x*2), str(luminosity), str(y*2)))