alter

Alter is a Node service that provides real-time image manipulation for responsive images using URL.

Comparison

Method	Pros	Cons
3rd Party	Very easy and simple to implement	- Lots of features which are not required
		- Bounded to 3rd party for any new requirement
		- Conversion of existing URLs
Pre-Compute	Easy to implement	- Too many moving parts in background
		- Too many files to stores
		- Maintaining a script for back-filling
Real Time	Easy and simple to implement	- High latencies
		- Heavy core machines

The proposed architecture is to put it behind a CDN for better performance.

The following transformations are available -

Resize
- Change either width or height will keep aspect ratio intact
- To resize image provide both height and width. Default crop is center.
Image format
- WebP
- JPEG
Blur
Thumbnail