nimagehide 
This provides a library and cli for hiding messages or other files in images.
For loading the images the library stb_image is used. Currently only png immages are supported but all loseless encodings supported by stb_image could easily be added.
usage
hiding
import nimagehide
let img = loadImage("baseImage.png") # loading the image
let secret = "Hello World".toBytes() # prepare the secret data as a byte sequence
img.hideData(data) # hide the data
img.storeImagePng("imageWithSecret.png") # store the image with the secret
hideAndStore("baseImage.png", "imageWithSecret.png", "Hello World") # can be done with one functiondiscovering
import nimagehide
let img = loadImage("imageWithSecret.png") # loading the image
let secret = img.discoverData # extract the data
echo secret # echo outputs 'Hello World'
discoverAndStore("imageWithSecret.png", "secret.txt") # discovers te data and stores it in 'secret.txt'
