Uniramp

Introduction

• Uniramp = Unicode + Ramp
  • Ramp: A char sequence for representing levels of gray values
  • “Standard” character ramp: $@B%8&WM*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,"^`'.
  • Support unicode character ramp information
• Uniramp also provides the image-to-text script as a test ground
  • An ASCII “Unicode” art generator

Background

• Most of image-to-text tools do not support custom charset
  • Either unicode characters, e.g., CJK characters
• Also, the ramp lacks font information
  • A single character have different shapes over various fonts

Program Flow

Installation

Install required packages:

Ubuntu 20.04:

apt install git \
            cmake \
            g++ \
            python3-dev \
            pybind11-dev \
            libfreetype-dev \
            python3-distutils \
            python3-pil

Clone the repo and build it:

git clone https://github.com/Cycatz-nycu/uniramp
cd uniramp
make

Run it with the example font:

python3 -m uniramp ramp -f tests/NotoSansCJK-Regular.ttc

Usage

Prefix arguments with python -m uniramp to use the program:

python -m uniramp -h 

usage: __main__.py [-h] {ramp,image} ...

positional arguments:
  {ramp,image}
    ramp        Print ramp infomation
    image       Convert an image to chars

options:
  -h, --help    show this help message and exit

Ramp

python -m uniramp ramp --help:

usage: __main__.py ramp [-h] -f FONT [-c CHARACTER_SET] [-g] [-w WIDTH]

options:
  -h, --help            show this help message and exit
  -f FONT, --font FONT  specify the font file
  -c CHARACTER_SET, --character-set CHARACTER_SET
                        specify the character set (default is [a-z][A-Z])
  -g, --graph           Print ramp graph
  -w WIDTH, --width WIDTH
                        specify the ramp bar width (default is 160 half-width characters)

Image

python -m uniramp image --help:

usage: __main__.py image [-h] -i IMAGE -f FONT [-c CHARACTER_SET] [-r] [-w WIDTH] [-o OUTFILE]

options:
  -h, --help            show this help message and exit
  -i IMAGE, --image IMAGE
                        specify the image
  -f FONT, --font FONT  specify the font file
  -c CHARACTER_SET, --character-set CHARACTER_SET
                        specify the character set (default is [a-z][A-Z])
  -r, --reverse         reverse the ramp order
  -w WIDTH, --width WIDTH
                        specify the generated image width (default is 80 characters)
  -o OUTFILE, --outfile OUTFILE
                        specify the output file (default the generated image will be printed to stdout)

Screenshot

Ramp

ASCII

• Inconsolata Regular:

• Source Code Pro Regular:

• Fira Code Regular:

CJK

• Noto Serif CJK TC Regular (思源宋體)

• Noto Sans CJK TC Regular (思源黑體)

Ramp Bar Graph

Image to Text

Mona Lisa

Octocat

Future Work

• Maximum/Minimum coverage rate analysis
• Half-width/full-width characters mixing
• Color support (ANSI escape sequences!)
• Conversion from generated text art back to an image

Reference

• http://paulbourke.net/dataformats/asciiart/
• https://github.com/RameshAditya/asciify
• https://github.com/LettError/coverage
• https://github.com/7sDream/fontfor