I want to use iiif http://iiif.io/ in my Codeigniter project but I haven't found any helpful link or demo which can help me to use this framework.
I'm also planning to use http://www.iiifhosting.com/ for hosting images and its demo shows they provide an image viewer too, but can I customise this viewer just like IIPMooViewer, Mirador, OpenSeadragon or any other viewer listed in iiif.io viewer list?
According to the documentation:
The IIIF [International Image Interoperability Framework] Image API specifies a web service that returns an image in response to a standard HTTP or HTTPS request. The URI can specify the region, size, rotation, quality characteristics and format of the requested image.
For the server, you can deploy your own server such as Loris or IIPImage server. You can also use an hosting service such as http://www.iiifhosting.com/ .
For the client, you can integrate a client such as Mirador, OpenSeadragon into your website but you can also directly use the IIIF protocol, using the URI syntax:
{scheme}://{server}{/prefix}/{identifier}/{region}/{size}/{rotation}/{quality}.{format}