问题

I am working on something where users can upload pictures(size of image is not limited). Now I have two options either compressing the image using PHP(Server side) or compressing the image on client's machine using JavaScript and then uploading it to the server. I wanted to ask which approach out of the two would be better to implement? Compression on server might lead to heavy load on the server so I thought of client side compression however if I upload an image of bigger size (lets assume 12MB or so) then browser freezes up for a while due to the script.

There is as such no code just a theoretical question. Currently I am using J-I-C for client side compression

Any other good library for client side image compression? and which approach would be better? Any help would be much appreciated.

回答1:

As @Xorifelse said, the question might be "too broad", but here are some ideas.

Cons

user input must not be trusted; by doing compression on the client-side, you will have to do some sanity check on the server side anyway
image compression (or optimization) involve complex operations, there is less choice in JavaScript than in other languages
since the operations are complex, you are putting the stress on your clients; if you don't control their configuration (hardware, browser and vers), a situation you can have almost only in an intranet, you will probably degrade (or fail) the browsing experience of some of your users
for all those reasons, client-side bugs are harder to track and fix and can quickly cost you more in development than adding resources to your servers

Pros

you offload some computation from your servers
you help people with a small bandwidth but powerful computers and recent browser to upload large images

Image compression tools

JPEG only

http://www.graphicsmagick.org/
http://www.vips.ecs.soton.ac.uk/
https://blarg.co.uk/blog/comparison-of-jpeg-lossless-compression-tools (jpegoptim vs jpegtran vs jpegrescan vs mozjpeg)

BGP

http://bellard.org/bpg/

My suggestion

if you need to spare your server, you can make the images optimization in batch, asynchronously at some time of the day when your server is not heavily loaded
if you have a lot of input, it can be cheaper to send the optimization to another server (ie: an on-demand virtual-machine at Amazon, DigitalOcean, Linode, etc., so you pay only when you need) than to upgrade your "main" server

来源：https://stackoverflow.com/questions/36112394/client-side-v-s-server-side-image-compression

标签

javascript

php

jquery

html

image-compression