get width and height of an image file
 

i am looking for a tool to get the width and height of an image file that is formatted in any of the major image formats like: bmp, gif, jpg, png, and more, even if the extension of the file name is wrong (for example a png file named as a gif file). it will need to figure out the format based on file contents.

it's output needs to be basically simple enough for a small shell script to parse it. output that is just the 2 numbers would be good.

ImageMagick's "identify" command does exactly that.

If you need a library, gdk-pixbuf loads many image formats.
Ed

we have very good search engines to find answers to questions like this.
for example: https://unix.stackexchange.com/quest...ze-of-an-image

i like using Cimg.h over imagemagick
https://cimg.eu/
or
https://github.com/GreycLab/CImg

There is also exiftool.

Typically the utilities use the file's magic number to determine image type and not the filename.

 

If you bothered to search, you should state what search terms you used, and what's wrong with the results you received.

This does several things:
1) it would demonstrate that you're not just being lazy.
2) it helps the next person using those same search terms to find an answer.
3) it allows responders to provide useful advice instead of repeating what you've already dismissed.

You use “identify” from ImageMagick.

Plain old file will do that.

i did not bother to search because i am unaware of a search engine capable of understanding a search expression like "...that produces easy to parse output".

it looks like exiftool (had to install it on my Xubuntu 20.4 x86) has the best output for many items of meta data.

And there is no one who knows what you mean by that.

That's a lame excuse. Prefix your search with "bash script" and the results will be something that is easy to parse.


Better yet, search for what you're trying to do with that information, and there's a fair chance someone has already done it and may have released the results.

probably not. but maybe with an exchange of questions and answers, we can work that out. i wonder how well search engines will do that in 50 years. i wonder if the search engines, then, will know what i mean by that or will they also need to ask me.

Several scripting and other languages have APIs for working with EXIF data, for more flexibility. For example, there are Image::EXIFTool in Perl and the exif module for Python3.

i get results like this:

Bash Scripting - Bash Echo Command - GeeksforGeeks

it's a local task, so no one would has done it. the information is simple, but a search didn't do as well as this thread. michaelk's answer worked best.