ASCII-Filter/sobel.py

# import scipy.ndimage as nd
# import imageio.v3 as iio
# import numpy as np
import logging
import math
import os

from PIL import Image
import pygame as pg

import filters

FORMAT = "%(levelname)s %(filename)s - %(message)s"
logging.basicConfig(level=logging.DEBUG, format=FORMAT)

IMAGE_PATH = 'sample-images/engine.PNG'
FONT_PATH = 'fonts/scientifica.ttf'


WHITE = (255,255,255)

TEXT_WIDTH = 6 # on font size 12 monocraft medium
TEXT_HEIGHT = 11

SCALE_FACTOR = 2
RESIZE_FACTOR = 2

SCALED_WIDTH = TEXT_WIDTH // SCALE_FACTOR
SCALED_HEIGHT = TEXT_HEIGHT // SCALE_FACTOR

DEBUG = True

if not os.path.exists('./debug/') and DEBUG:
    os.makedirs('./debug')

# '█@?OPoci. '
CHARS = list(reversed([
    u'█',
    '@',
    '?',
    'O',
    'P',
    'o',
    'c',
    'i',
    '.',
    ' '
]))

def main():

    image = Image.open(IMAGE_PATH)
    image = image.resize((image.width * RESIZE_FACTOR, image.height * RESIZE_FACTOR))
    logging.debug(f'Image Size: {image.size}')

    L_image = image.convert('L')
    logging.debug(f'L_image Size: {L_image.size}')

    dog = filters.difference_of_gaussians(image)
    logging.debug(f'Dog Size: {dog.size}')

    dog.save('dog.png')

    sb, gradient = filters.sobel(dog)

    w, h = sb.size

    sb.save('sobel.png')

    text_grid_width = w / SCALED_WIDTH
    text_grind_height = h / SCALED_HEIGHT

    pg.init()
    font = pg.font.Font(FONT_PATH, 12)
    window = pg.display.set_mode((text_grid_width * TEXT_WIDTH, text_grind_height * TEXT_HEIGHT))

    y_offset = 0

    for y in range(math.floor(h / SCALED_HEIGHT)):
        x_offset = 0

        for x in range(math.floor(w / SCALED_WIDTH)):
            histogram = {}

            # Collect the most common char for a group of pixels
            colors = []

            for y2 in range(SCALED_HEIGHT):
                for x2 in range(SCALED_WIDTH):

                    real_x = x2 + x_offset
                    real_y = y2 + y_offset

                    gradient_v = gradient[real_y * w + real_x]

                    char = ' '

                    if gradient_v:
                        char = match_gradient(gradient_v)
                    else:
                        char = CHARS[round(L_image.getpixel((real_x, real_y))/(255/len(CHARS))) - 1]

                    if char in histogram:
                        histogram[char] += 1
                    else:
                        histogram[char] = 1

                    colors.append(image.getpixel((real_x, real_y)))

            color_avg = average_colors(colors)

            # get most common
            most_common = None
            score = float('-inf')
            for char in histogram:
                if histogram[char] > score:
                    score = histogram[char]
                    most_common = char

            rendered_char = font.render(str(most_common), True, color_avg)
            window.blit(rendered_char, (x * TEXT_WIDTH, y * TEXT_HEIGHT))

            x_offset += SCALED_WIDTH

        y_offset += SCALED_HEIGHT

    pg.display.update()
    pg.image.save(window, "render.png")
    pg.quit()

    if DEBUG:
        sb.save('debug/sobel-dog.png')
        dog.save('debug/dog.png')

        # Draw only the ASCII edges
        pg.init()
        font = pg.font.Font(FONT_PATH, 12)
        window = pg.display.set_mode((text_grid_width * TEXT_WIDTH, text_grind_height * TEXT_HEIGHT))

        y_offset = 0

        for y in range(math.floor(h / SCALED_HEIGHT)):
            x_offset = 0

            for x in range(math.floor(w / SCALED_WIDTH)):
                histogram = {}

                # Collect the most common char for a group of pixels
                colors = []

                for y2 in range(SCALED_HEIGHT):
                    for x2 in range(SCALED_WIDTH):

                        real_x = x2 + x_offset
                        real_y = y2 + y_offset

                        gradient_v = gradient[real_y * w + real_x]

                        char = ' '

                        if gradient_v:
                            char = match_gradient(gradient_v)
                        else:
                            char = ' '

                        if char in histogram:
                            histogram[char] += 1
                        else:
                            histogram[char] = 1

                        colors.append(image.getpixel((real_x, real_y)))

                color_avg = average_colors(colors)

                # get most common
                most_common = None
                score = float('-inf')
                for char in histogram:
                    if histogram[char] > score:
                        score = histogram[char]
                        most_common = char

                rendered_char = font.render(most_common, True, color_avg)
                window.blit(rendered_char, (x * TEXT_WIDTH, y * TEXT_HEIGHT))

                x_offset += SCALED_WIDTH

            y_offset += SCALED_HEIGHT

        pg.display.update()
        pg.image.save(window, "debug/edges-render.png")
        pg.quit()

# TODO @0x01FE : refactor plz increment by 30 & 60
def match_gradient(n: float) -> str:

    n = abs(n)

    if n < math.radians(30):
        return '|'
    elif n < math.radians(60):
        return '/'
    elif n < math.radians(120):
        return '-'
    elif n < math.radians(150):
        return '\\'
    elif n < math.radians(210):
        return '|'
    elif n < math.radians(240):
        return '/'
    elif n < math.radians(300):
        return '-'
    elif n < math.radians(330):
        return '\\'
    else:
        return '|'

def average_colors(colors: list):
    avg = [0 for x in range(len(colors[0]))]

    for color in colors:
        for i, num in enumerate(color):
            avg[i] += num

    for i, n in enumerate(avg):
        avg[i] /= len(colors)

    return avg

if __name__ == '__main__':
    main()