ImageIO - get image type and exif data

Question

Given some source file (or more generic - input stream), I need to find out

is it an image
if it is an image, then retrieve its type (png/jpeg/gif/etc)
retrieve exif data, if available

I looked at the API, but it is not clear how to get the type of image or Exif data.

The file extension is never a guarantee of the file type. Nothing can stop anyone from illegally renaming the file. — Matthew Cachia, Mar 11 '15 at 06:29

score 34 · Accepted Answer · answered Jul 03 '12 at 11:55

34

Last time I had to do this, a couple of years ago, the standard API couldn't read EXIF data. This library can do so though:

http://www.drewnoakes.com/code/exif/

answered Jul 03 '12 at 11:55

OpenSauce

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It seems that this product is the metadata-extractor proposed by matt burns below – Panayotis Jun 05 '16 at 19:20

score 17 · Answer 2 · edited Feb 09 '15 at 19:59

17

Easy answer: Use https://github.com/drewnoakes/metadata-extractor/

If you're crazy/brave/curious, you could get image type from the stream by reading the first few bytes (these are magic numbers). I believe the exif is generally at the start of the stream too.

edited Feb 09 '15 at 19:59

Drew Noakes

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answered Jul 03 '12 at 11:57

matt burns

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Magic number link → Error 403 Forbidden. – 猫IT Aug 25 '19 at 08:09
Here the `magic number` link from the internet archive https://web.archive.org/web/20170611142413/https://www.astro.keele.ac.uk/oldusers/rno/Computing/File_magic.html – SubOptimal Aug 08 '23 at 09:05

score 8 · Answer 3 · answered Feb 10 '14 at 21:21

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It's an old thread, but I was doing this recently and found the Apache Tika library useful. Particularly for analysing generic streams to detect what content is in them.

Thought it might help others.

http://tika.apache.org/

answered Feb 10 '14 at 21:21

Eurospoofer

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Note that Tika uses metadata-extractor under the hood :). – Andrew Aylett Nov 30 '14 at 18:05

ImageIO - get image type and exif data

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