image_console_printer Namespace Reference

This module contains code that converts image data to formats suitable for printing to console. More...

Functions
def	_alpha_blend (src, dst)
def	_generate_grayscale_for_image (pixels, width, height, bgcolor)
def	print_image_to_console (img)

Detailed Description

This module contains code that converts image data to formats suitable for printing to console.

Based on https://github.com/hit9/img2txt by @hit9 with minor modifications, BSD license as follows:

Function Documentation

_alpha_blend()

def image_console_printer._alpha_blend (   src,   dst  )

private

def _alpha_blend(src, dst):
    # Does not assume that dst is fully opaque
    # See https://en.wikipedia.org/wiki/Alpha_compositing - section on "Alpha Blending"
    src_multiplier = (src[3] / 255.0)
    dst_multiplier = (dst[3] / 255.0) * (1 - src_multiplier)
    result_alpha = src_multiplier + dst_multiplier
    if result_alpha == 0:       # special case to prevent div by zero below
        return (0, 0, 0, 0)
    else:
        return (
            int(((src[0] * src_multiplier) + (dst[0] * dst_multiplier)) / result_alpha), 
            int(((src[1] * src_multiplier) + (dst[1] * dst_multiplier)) / result_alpha),
            int(((src[2] * src_multiplier) + (dst[2] * dst_multiplier)) / result_alpha),
            int(result_alpha * 255) 
        ) 
           

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_generate_grayscale_for_image()

def image_console_printer._generate_grayscale_for_image (   pixels,   width,   height,   bgcolor  )

private

def _generate_grayscale_for_image(pixels, width, height, bgcolor):
 
    # grayscale
    color = "MNHQ$OC?7>!:-;. "
 
    string = ""
    # first go through the height,  otherwise will rotate
    for h in range(height):
        for w in range(width):
 
            rgba = pixels[w, h]
 
            # If partial transparency and we have a bgcolor, combine with bg
            # color
            if rgba[3] != 255 and bgcolor is not None:
                rgba = _alpha_blend(rgba, bgcolor)
 
            # Throw away any alpha (either because bgcolor was partially
            # transparent or had no bg color)
            # Could make a case to choose character to draw based on alpha but
            # not going to do that now...
            rgb = rgba[:3]
 
            string += color[int(sum(rgb) / 3.0 / 256.0 * 16)]
 
        string += "\n"
 
    return string
 

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print_image_to_console()

def image_console_printer.print_image_to_console

(

img

)

def print_image_to_console(img):
    if img.mode != 'RGBA':
        img = img.convert('RGBA')
 
    fill_string = "\x1b[49m"
    fill_string += "\x1b[K"          # does not move the cursor
    sys.stdout.write(fill_string)
 
    pixels = img.load()
    sys.stdout.write(_generate_grayscale_for_image(pixels, img.width, img.height, None))
 
    # Undo residual color changes, output newline because
    # generate_ANSI_from_pixels does not do so
    # removes all attributes (formatting and colors)
    sys.stdout.write("\x1b[0m\n")

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