ARarendtio·Dec 13, 2020
This is the line that makes the difference:
https://github.com/n7olkachev/imgdiff/blob/master/pkg/imgdif...
In Imgdiff: Faster than the fastest pixel-by-pixel image difference tooln7olkachev
imgdiff
Go2020–2020
n7olkachev / imgdiff
imgdiff
Faster than the fastest in the world pixel-by-pixel image difference tool.
5Distinct people
5Mentions
0Explicit recommenders
1.7KGitHub stars
What to know before exploring
What it is
Faster than the fastest in the world pixel-by-pixel image difference tool.
GitHub
Where it is used
No documented product use has been verified yet.
What people are saying
No recommendation phrase was found in the indexed comments.
No classified warning is attached to this page. Read the discussions before treating silence as approval.
Also in these discussions
No other repository is repeatedly linked in the same discussions.
This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 12:54:37 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by hour5 dated mentions
Observed mentions: 2020-12-12 19:59:48 UTC to 2020-12-13 07:51:21 UTC.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| Dec 12, 19:00 | 2020-12-12 19:00:00 UTC | 2020-12-12 20:00:00 UTC | 1 | 1 | 0 |
| Dec 12, 20:00 | 2020-12-12 20:00:00 UTC | 2020-12-12 21:00:00 UTC | 0 | 0 | 0 |
| Dec 12, 21:00 | 2020-12-12 21:00:00 UTC | 2020-12-12 22:00:00 UTC | 0 | 0 | 0 |
| Dec 12, 22:00 | 2020-12-12 22:00:00 UTC | 2020-12-12 23:00:00 UTC | 0 | 0 | 0 |
| Dec 12, 23:00 | 2020-12-12 23:00:00 UTC | 2020-12-13 00:00:00 UTC | 0 | 0 | 0 |
| Dec 13, 00:00 | 2020-12-13 00:00:00 UTC | 2020-12-13 01:00:00 UTC | 1 | 0 | 1 |
| Dec 13, 01:00 | 2020-12-13 01:00:00 UTC | 2020-12-13 02:00:00 UTC | 0 | 0 | 0 |
| Dec 13, 02:00 | 2020-12-13 02:00:00 UTC | 2020-12-13 03:00:00 UTC | 1 | 0 | 1 |
| Dec 13, 03:00 | 2020-12-13 03:00:00 UTC | 2020-12-13 04:00:00 UTC | 0 | 0 | 0 |
| Dec 13, 04:00 | 2020-12-13 04:00:00 UTC | 2020-12-13 05:00:00 UTC | 0 | 0 | 0 |
| Dec 13, 05:00 | 2020-12-13 05:00:00 UTC | 2020-12-13 06:00:00 UTC | 1 | 0 | 1 |
| Dec 13, 06:00 | 2020-12-13 06:00:00 UTC | 2020-12-13 07:00:00 UTC | 0 | 0 | 0 |
| Dec 13, 07:00 | 2020-12-13 07:00:00 UTC | 2020-12-13 08:00:00 UTC | 1 | 0 | 1 |
What Hacker News says
5 sourcesWorth noting it's ~100-lines of Go code that's quite readable:
https://github.com/n7olkachev/imgdiff/blob/master/pkg/imgdif...
https://github.com/n7olkachev/imgdiff/blob/master/pkg/yiq/de...
In Imgdiff: Faster than the fastest pixel-by-pixel image difference toolhttps://github.com/n7olkachev/imgdiff/blob/9b2a87e1b729c70b5...
Yep, uses as many goroutines as the number of CPUs, that's about it. Saying it's 3x faster or whatever in "benchmarks" without even saying what CPU is used in the benchmarks is just sketchy.
In Imgdiff: Faster than the fastest pixel-by-pixel image difference toolEven before you get into GPU, it looks like you could do the normalisation here https://github.com/n7olkachev/imgdiff/blob/master/pkg/yiq/de... using _mm_mul_ps or _mm256_mul_ps depending on availability instead of standard math. (CPU based vector processing)
There's also bound to be some vector compare trick as well which falls back to pixel-by-pixel only for differences.
I think there are quite a few simple tricks you could apply here to get a bit more performance... Starting with sacrificing some memory and decoding a chunk of image at a time rather than calling .At(x,y) every time. And maybe improving local cache by dividing the image in `cpu` parts rather than having the work interleaved.
In Imgdiff: Faster than the fastest pixel-by-pixel image difference toolImgdiff: Faster than the fastest pixel-by-pixel image difference tool
181 points · Open discussion