termpic

README

TermPic

An image renderer for the terminal. Written in Go.

Usage

You need Golang to build the binary.

# Build it
$ go build -o termpic main.go

# Run it
$ ./termpic test.png <skip value>

The skip Parameter

The second argument to termpic is the skip parameter. This defines how many pixels to skip (along both the x and y axes) after rendering a pixel. Default is set to 0.

Obviously the lower the value of skip, the better the detail and resolution of the rendered image. But a higher value can be useful when your terminal is not be wide enough to display the whole image. Since each pixel is half the height of the terminal cursor, which is MASSIVE compared to a pixel on the screen, your max resolution will be lower.

Caveats

• Currently only works with png and jpeg images.

Algorithm

We use ANSI escape sequences to control the background and text colours of the terminal as we render blocks.

We construct 2 rows of pixels at a time. The lower row is constructed by setting the background colour of the terminal to the colour of the pixel we want to render, and the upper row is constructed by rendering the UPPER_HALF_BLOCK (▀) character, which is a square. Printing this character renders both the background and the block, thus rendering two pixels vertically.