imsz

Get width and height from an image file reading as few bytes as possible.

Why?

A few years ago I answered a Stackoverflow question "Get Image size WITHOUT loading image into memory" (using Python). The canonical answer for dealing with images in Python is the PIL library but it is a huge library if you just want to get width and height. I rolled up my sleeves and wrote a small function to do just this. Over the years people sent patches implementing new image formats and refactoring the code until I could not recognize it anymore. I always wanted to tidy it up a bit, may be reimplement it as a C module...

Am I rusty?

In the last 10 years I've used Python for everything. This saturday afternoon I wanted to answer the question: "at my age, can I still learn a new computer language?". So I decided to try Rust and this is the result. It was a pleasant surprise, if you are familiar with C/C++ Rust is really easy to pick up - and I see some Python influence here and there.

I don't expect it to be very idiomatic Rust, it is my first Rust project so be kind!

First impressions

There are many things I like in Rust. I'm still looking for a good debugger, the one I was using with VSCode is unable to show the values in a HashMap, for example.

Usage:

There is a simple example binary:

> .\target\debug\imsz.exe  tenor.gif  
tenor.gif: git, 220 x 159

> .\target\debug\imsz.exe -h
Usage:
  C:\Users\paulos\work\imsz\target\debug\imsz.exe [OPTIONS] FILES [...]

The imsz library gets image size from files, this is a demo application.

Positional arguments:
  files                 List of files to process

Optional arguments:
  -h,--help             Show this help message and exit
  -v,--verbose          Be verbose
  -V,--version          Display version and exits

The relevant parts:

use imsz::imsz

...

let info = imsz(fname);
println!("{}: {}, {} x {}", fname, info.format, info.width, info.height);
// tenor.gif: gif, 220 x 159