BasicTextRender.jl

Warning.. very basic.. More of an experiment.. Concatenates characters from pre-rendered lookup images, then resizes and colors. 100% julia, no libs. Gets blurry if font height is greater than ~90 pixels.

Provides rendertext for generating a rendered image of a string and overlaytext! for directly overlaying text on a loaded image.

Currently built to support truly monospaced fonts only, and Courier is the only font that is provided. (other open source licensed fonts welcome via PR, see gen/makeCharLookups.jl)

Generating rendered text

> using BasicTextRender
> img = rendertext("Hello world", height=50)
50×316 Array{RGBA{Float64},2} with eltype RGBA{Float64}:
...
> using FileIO
> save("img.png", img)

using BasicTextRender, ColorTypes
img = rendertext("Hello world", height=30, color=RGBA(1.0,0.0,0.0,1.0), backgroundColor=RGBA(1.0,1.0,0.0,1.0))

Overlaying text on a loaded image

img = rand(RGBA{Float64},80,700)
overlaytext!(img, "BasicTextRender.jl", 60, (10,40))
save("logo.png", img)

Speed (slow then fast-ish)

The first time rendertext runs it should take about 5 seconds, as it loads the character lookup table, but subsequent calls for the same scale and font will be fast.

using BenchmarkTools
@btime rendertext("Hello world", height=30) #599.991 μs (352 allocations: 2.28 MiB)