How to combine images into JPG image/sprite and write metadata on Rails or iOS

Question

We want to combine several PNG and JPG images into one JPG image/sprite and also write metadata of five fields (i.e., name, personal URL, icon URL, bio, title) to the sprite.

The metadata will only get read by our iOS app, so we can use fields for any purpose (e.g., instead of writing copyright data, we could use the copyright field for storing the personal URL).

Some other StackOverflow posts like this tackle writing metadata in iOS, but we need to write metadata while combining images into one JPG.

Is this possible on iOS? How about Rails? Any gotchas to watch out for?

score 1 · Answer 1 · answered Aug 14 '14 at 16:55

1

In Rails you could use Image Magick (http://www.imagemagick.org/), via the RMagick gem. Note you'll need to install ImageMagick on the host system, which may be non-trivial, but it has the capabilities you're looking for.

answered Aug 14 '14 at 16:55

i_am_Halloran

196
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Yes. See here: http://stackoverflow.com/questions/20901713/how-to-write-custom-metadata-to-an-image-created-by-rmagick – i_am_Halloran Aug 14 '14 at 17:52
"Image metadata may be changed by marshaling." [link](http://www.imagemagick.org/RMagick/doc/usage.html) – i_am_Halloran Aug 14 '14 at 17:55
To be clear, I've not done exactly what you're asking with Rmagick, but I've used it for other things, and it works well, plus lots of support. – i_am_Halloran Aug 14 '14 at 17:56
I'm curious; did you end up using RMagick? Or find another solution? – i_am_Halloran Aug 25 '14 at 03:58

How to combine images into JPG image/sprite and write metadata on Rails or iOS

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