C ascii maker

Simple command line that can take an input image and generator ascii-art from the image. Check this folder for couple example outputs. Making terminal characters smaller will improve output quality significantly.

Special thanks to Xander Gouws and his youtube video for inspiring me to create this project. Link To Video

Usage:

./cascii.exe path/to/image.png -other [value] --flags

To build:

# Regular build
make

# build with clang (with optimzations on)
make clang

# compiled with optimizations
make release

Build Requirements:

• GCC or CLANG version that supports C99
• GNU Make

Optional flags

• -mw maximum width (Default terminal width or 96 characters)

• -mh maximum height (Default terminal height or 64 characters)

• -set Sobel edge detect threshold (DEFAULT: 67.0) (yes I know this feels like a joke but it works better than I expected)

• -cr Character Ratio (Default 2.0)

• -ba Brighten image amount (Default 1.0 -> Doesn't brighten) Note that any value over 2.0 may result in overly bright images

• --usebw output with no color (Default OFF)

• -c Use custom charcters for brightness in ascending order (Default: " .-=+*x#$&X@") Note that you can wrap "" around your input to include the whitespace character

• -o Output to ASCII to file (DEFAULT OFF)

• -r Read outputted file (Slightly different usage -> ./cascii.exe -r file_to_read.txt)

Note that if you use output on a colored image without setting the --usebw flag you may need to use a terminal viewer to view the image properly. The color is output using Ansi escape sequences. However, if you do use the flag --usebw you may view the outputted file with a regular text viewer.

# viewing outputted image 
./cascii.exe lightning.jpg -o lightning.txt

# use cat
cat lightning.txt

# use less to view
less -R lightning.txt

# or just use cascii to read it
./cascii.exe -r lightning

# example with --usebw flag
./cascii.exe lightning.jpg -o lightning-normal.txt --usebw

# use any normal text editor to view
nvim lightning-normal.txt

# or you can open with notepad
notepad++ lightning-normal.txt

Example use cases

# use default paramters for everything
./cascii.exe lightning.jpg

# Dont brighten image and effectively turn off the sobel threshold
./cascii.exe lightning.jpg -ba 1 -set 255.0

# produce black and white output
./cascii.exe lightning.jpg --usebw

# Output to a file
./cascii.exe lightning.jpg -o lightning.txt

# Using custom characters for an image using whitespace, a, b and E
./cascii.exe images/imposter.jpg -c " abE" 

How it works (In a nutshell..)

• First loads an image using stb image
• Resizes image to match given parameters or the terminal height and width while accounting for the character ratio in terminals (typically 1 to 2)
• Does an Image convolution across the given image using a sobel Kernel to give sharper edges
• Uses luminosity for the sobel threshold and outputs | \ / _ depending on which direction the sobel is
• Use Ansi Escape codes to output color to the terminal

Couple Examples