HDR Codec

Encode and decode HDR color data to and from low-bit-depth RGBA files.

Summary:

usage: tcio-hdr-codec [-h] (--encode | --decode) [--igf ] [--ogf ] [--format {logluv}] input output

Encode and decode high dynamic range color data.

positional arguments:
  input              Input image file path
  output             Output image file path

optional arguments:
  -h, --help         show this help message and exit
  --encode, -e       Encode mode
  --decode, -d       Decode mode
  --igf []           Input graphics format (default: unknown)
                     CHOICES:
                         sfloat16, sfloat32
                         uint8, uint16, uint32
  --ogf []           Output graphics format (default: unknown)
                     CHOICES: [same as above]
  --format {logluv}  Format

Example usage:

$ tcio-hdr-codec --encode hdr_image.exr encoded_image.png

$ tcio-hdr-codec --decode encoded_image.png hdr_image.exr

Script:

#!/usr/bin/env python
"""Encode and decode high dynamic range color data."""
import os
import argparse
from argparse import RawTextHelpFormatter
from tinycio import fsio, Codec

def main_cli():
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawTextHelpFormatter)
    parser.add_argument('input', type=str, help='Input image file path')
    parser.add_argument('output', type=str, help='Output image file path')
    mode = parser.add_mutually_exclusive_group(required=True)
    mode.add_argument('--encode', '-e', action='store_true', help='Encode mode')
    mode.add_argument('--decode', '-d', action='store_true', help='Decode mode')
    parser.add_argument(
        '--igf', 
        type=str, 
        default="unknown", 
        const="unknown",
        nargs='?',
        choices=['sfloat16','sfloat32','uint8','uint16','uint32'],
        metavar='', 
        help='Input graphics format (default: %(default)s)\n' + \
            'CHOICES:\n' + \
            '    sfloat16, sfloat32 \n' + \
            '    uint8, uint16, uint32 \n'
        )
    parser.add_argument(
        '--ogf',
        type=str, 
        default="unknown", 
        const="unknown",
        nargs='?',
        choices=['sfloat16','sfloat32','uint8','uint16','uint32'],
        metavar='',
        help='Output graphics format (default: %(default)s)\n' + \
            'CHOICES: [same as above]'
        )
    parser.add_argument(
        '--format', 
        type=str, 
        choices=['logluv'],
        default='logluv',
        help='Format'
        )
    args = parser.parse_args()

    fp_in   = os.path.realpath(args.input)
    fp_out  = os.path.realpath(args.output)
    gf_in   = args.igf.strip().upper()
    gf_out  = args.ogf.strip().upper()

    try:
        if args.format == 'logluv':
            if args.encode:
                im_hdr = fsio.load_image(fp_in, graphics_format=fsio.GraphicsFormat[gf_in])
                im_hdr = fsio.truncate_image(im_hdr)
                im_logluv = Codec.logluv_encode(im_hdr)
                fsio.save_image(im_logluv, fp_out) 
            elif args.decode:
                im_logluv = fsio.load_image(fp_in, graphics_format=fsio.GraphicsFormat[gf_in])
                im_hdr = Codec.logluv_decode(im_logluv)
                fsio.save_image(im_hdr, fp_out)
            else:
                raise Exception('unexpected mode')
        else:
            raise Exception('unexpected format')
        print(f'saved image to: {fp_out}')
    except Exception as e: 
        print(f'cannot encode/decode: {e}')
        
if __name__ == '__main__':
    main_cli()