image_convolution's Introduction

Image Convolution

This was created for a parallel programming assignment at DSU. The main code is written in C with OpenMP. It uses Sean T. Barrett's libraries for image manipulation.. The front-end is in Node, using node-ffi to bind to the C code. The Scientist and Engineer's Guide to Digital Signal Processing was indispensable in understanding convolution, and in providing good kernel examples.

Disclaimers

I was a complete novice at Node when I made this, and the time to learn it appropriately was very limited. I followed this tutorial and that's pretty much it. Transferring images from the client to the server is very, very slow.^* I am not sure why, but any attempt to clear out the node-modules folder and reinstall with npm introduces bugs. If you want to fix that for some reason, here's what I believe the dependencies are:

  "dependencies" :
    { "express" : "^4.14.0" ,
      "body-parser" : "^1.15.2" ,
      "ffi" : "^2.2.0" ,
      "ref" : "^1.3.3" ,
      "ref-struct" :"^1.1.0" ,
      "ref-array" : "^1.2.0" ,
      "pug" : "^2.0.0-beta6"
    }

Usage

Anyway, it should work if you copy it as-is, cd to web, and run node index.js. Select an image, mess with the settings, and click go. For example, try entering this for the convolution kernel:

0 0 0
0 1 0
0 0 -1

and leave the divisor as 1. After you've picked an image, click "Go". If everything is working, then the server should output something like this:

Divisor: 1
Kernel:
0.000000	0.000000	0.000000	
0.000000	1.000000	0.000000	
0.000000	0.000000	-1.000000	
Image width: 800, height: 600, components: 4

and after a few seconds/minutes, your original image will be replaced in the canvas by your convolved image.

_{^{IIRC, raw image data is transferred from client to server in JSON. I tried to look into Streams, but it was a bit too much effort at the time. Now I think looking into compression would also be a good idea, at least maybe gzip.}}

Recommend Projects

metaphorshear / image_convolution Goto Github PK