What are reasonable thumbnail sizes for mobile devices and HTML5 app?

android, html, ipad, iphone, thumbnails

Solution

Here is a great, related article:

http://cloudinary.com/blog/top_10_mistakes_in_handling_website_images_and_how_to_solve_them

And we are implementing these standard thumbnail sizes for our mobile apps:

75x75 - Gallery thumbnail (filename-small.jpg) 150x150 - Gallery thumbnail retina (filename-smallx2.jpg) 480x320 - Full image iPhone (filename-medium.jpg) 1024x768 - Full image Retina (filename-large.jpg)

Our original files are full-on HD digital camera photos.

Problem

I'm building a REST API that will be used by native Android and iOS apps as well as HTML5 in Browsers. I have several images that will be sent in some API calls. I want to generate some thumbnails so that every device gets the proper image size (smaller devices will get smaller pictures, and so on). I couldn't find any information regarding which sizes most people are using. I would like to know which sets of resolutions are reasonable (or usual) to use.

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