I used Photoshop to convert a jpeg photo into a targa bump map file. I want to read up this file from the directory containing the JavaScript code and do a little bit of processing to create a bump map texture (remove the 18-byte header, flip BGR -> RGB). But all of the examples I've found for loading texture information from files use gifs, which apparently are acceptable with no further processing. Can someone give me a hint on how to get a binary file (such as a targa file) into JavaScript arrays, which I can then pass to a texture?

Alternatively, maybe there's an output from Photoshop and some JavaScript syntax to get to a bump map texture without JavaScript manipulation of the data?