RIF

local index = {}
for i=0,15 do
    index[2^i] = i
end
local function combine(bg, fg)
    return bit.blshift(bg, 4) + fg
end
local function split(color) local bg = bit.brshift(color, 4) local fgFactor = bg * 16 local fg = color - fgFactor return bg, fg end
function image(x, y)
    local imdata = {}
    for i=1,x do
        imdata[i] = {}
        for j=1,y do
            imdata[i][j] = {
                ["color"] = 0,
                ["char"] = " "
            }
        end
    end
    local obj = {}
    function obj.place(xpos, ypos, char)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        imdata[xpos][ypos].char = char
        return obj
    end
    function obj.setTextColor(xpos, ypos, color)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        if not index[color] then
            error('Invalid color!', 2)
        end
        local bg, _ = split(imdata[xpos][ypos].color)
        local fg = index[color]
        imdata[xpos][ypos].color = combine(bg, fg)
        return obj
    end
    function obj.setBackgroundColor(xpos, ypos, color)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        if not index[color] then
            error('Invalid color!', 2)
        end
        local _, fg = split(imdata[xpos][ypos].color)
        local bg = index[color]
        imdata[xpos][ypos].color = combine(bg, fg)
        return obj
    end
    function obj.export()
        local data = {}
        for i = 1, y do
            data[i] = ""
            for j = 1, x do
                data[i] = data[i] .. string.char(imdata[j][i].color) .. imdata[j][i].char
            end
        end
        return textutils.serialise(
            {
                ["x"] =  x,
                ["y"] =  y,
                ["data"] = data
            }
        )
    end
    function obj.get(xpos, ypos)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        local bg, fg = split(imdata[xpos][ypos].color)
        return bg, fg, imdata[xpos][ypos].char
    end
    function obj.getSize()
        return x,y
    end
    return obj
end
function load(data)
    -- Parsing image starts here
    local data = textutils.unserialise(data)
    local imdata = {}
    local x = data.x
    local y = data.y
    for i=1,x do
        imdata[i] = {}
        for j=1,y do
            imdata[i][j] = {
                ["color"] = 0,
                ["char"] = " "
            }
        end
    end
    for i=1,y do
        local dpart = data.data[i]
        for j=1,x do
            local ppart = string.sub(dpart, 2*j - 1, 2*j)
            imdata[j][i] = {
                ["color"] = string.byte(string.sub(ppart, 1,1)),
                ["char"] = string.sub(ppart, 2, 2)
            }
        end
    end
    local obj = {}
    function obj.place(xpos, ypos, char)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        imdata[xpos][ypos].char = char
        return obj
    end
    function obj.setTextColor(xpos, ypos, color)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        if not index[color] then
            error('Invalid color!', 2)
        end
        local bg, _ = split(imdata[xpos][ypos].color)
        local fg = index[color]
        imdata[xpos][ypos].color = combine(bg, fg)
        return obj
    end
    function obj.setBackgroundColor(xpos, ypos, color)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        if not index[color] then
            error('Invalid color!', 2)
        end
        local _, fg = split(imdata[xpos][ypos].color)
        local bg = index[color]
        imdata[xpos][ypos].color = combine(bg, fg)
        return obj
    end
    function obj.export()
        local data = {}
        for i = 1, y do
            data[i] = ""
            for j = 1, x do
                data[i] = data[i] .. string.char(imdata[j][i].color) .. imdata[j][i].char
            end
        end
        return textutils.serialise(
            {
                ["x"] =  x,
                ["y"] =  y,
                ["data"] = data
            }
        )
    end
    function obj.get(xpos, ypos)
        if xpos > x then
            error('x pos too high!',2)
        end
        if ypos > y then
            error('y pos too high!', 2)
        end
        local bg, fg = split(imdata[xpos][ypos].color)
        return 2^bg, 2^fg, imdata[xpos][ypos].char
    end
    function obj.getSize()
        return x,y
    end
    return obj
end
function compress(data)
    local data = textutils.unserialise(data)
    local str = ""
    str = str .. data.x .. "s"
    str = str .. data.y .. "s"
    for i=1,data.y do
        str = str .. data.data[i]
    end
    return str
end
function uncompress(data)
    local tab = {}
    for s in string.gmatch(data, "([^s]+)") do
        table.insert(tab, s)
    end
    local rdata = {
        ["x"] = tonumber(tab[1]),
        ["y"] = tonumber(tab[2]),
        ["data"] = {}
    }
    local ndata = ""
    local amnt = #tab[1] + 2 + #tab[2]
    ndata = string.sub(data, amnt + 1)
    for i=1,rdata.y do
        rdata.data[i] = string.sub(ndata, rdata.x * i * 2 - rdata.x * 2 + 1, rdata.x * i * 2)
    end
    return textutils.serialise(
        rdata
    )
end