Question

I’ve been looking, but I cannot find an image file to CSV converter that works. Do you have a program/code/suggestion in some language that will output me something similar to
1,1, 255,255,255, 0
1,2, 255,0,255, 0
that is easy to understand. I know Lua, but I’m fine using other languages I don’t understand to get the output.

Thanks.

I’d like to do this because I have a mediocre fractal terrain generation script that can only be displayed over a game(roblox) with their GUIs, and takes 400k MB. I’d much rather load a quick 500×500 png file, after writing it with the terrain stuff.

Answer 1

You can use Lua-GD, a binding for C’s gdlibrary for drawing.

You must first install gd and all it’s dependencies, then install Lua-GD, as the manual says.

Here is the Lua code to do what is requested:

require 'gd'

local f = io.open('file.csv', 'w')

local img = gd.createFromPng('image.png')
for y = 1, img:sizeY() do
    local line = ''
    for x = 1, img:sizeX() do
        -- I'm not sure about the return of this function, 
        -- the documentation is unclear. But it should not 
        -- be very different.
        local r, g, b = img:getPixel(x, y)
        line = line .. r .. ', ' .. g .. ', ' .. b .. ', '
    end
    line = line:gsub(',$', '\n') -- remove last comma
    f:write(line)
end
f:close()

Note that, for simplicity, no error handling is done.