Working with images in IPFS

Are there good examples of working with images and IPFS? A scenario I’m thinking about:

  1. Upload an image to IPFS.
  2. Show this image from IPFS on an HTML page.
  3. Make a preview of an uploaded image, so it could be loaded faster on UI.
  4. Anything special about gifs?

Images can take a data URL as a src, which you can create from a Blob, which you can create from a Uint8Array so you could do something like:

const toBuffer = require('it-to-buffer') // or it-concat for more performant BufferLists

const buffer = await toBuffer(ipfs.cat(cid))
const blob = new Blob(buffer)

const myImage = document.querySelector('img')
myImage.src = URL.createObjectURL(blob)
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One other option would be storing your images and other formats as “unixfs objects”. The nide thing about this is that if you view the content over a gateway, the gateway will do mime-type detection and enable serving the content via the gateway.

storing your images and other formats as “unixfs objects”

How to do this?

For go-ipfs you can use the ipfs add command. I dont personally use js-ipfs so I’m not 100% sure what the equivalent command would be, but it should be something like add, addFromFS and there may be one other one.

In the case of the js-ipfs-http-client package it’s instanceOfAPIClient.add, and insanceOfAPIClient.addFromFS

Yes, the equivalent here would be just:

const myImage = document.querySelector('img')
myImage.src = `https://gateway.ipfs.io/${cid}`

But you’re not really getting any of the benefits of IPFS here as the image is being served over HTTP.

There’s also a caveat that the gateway is a shared public resource and not one that you should rely on to power your app, instead you should set up your own gateways.

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Key point here! Thanx @achingbrain

I mean if you’re using a remote gateway sure, but you can always use a local gateway on your laptop or whatever. Gateways have their uses, locally, or publicly; A gateway isn’t an exclusively public resource unless you make it.