For some reason this doesn’t work out of the box. The official pHash 0.9.6 from phash.org won’t build on CentOS even though ffmpeg-devel is installed. I don’t even think this is the fault of pHash, I think the CentOS package is broken. When trying to build it I get: libtool: compile: g++ -DHAVE_CONFIG_H -I. -I.. …

Continue reading Building pHash 0.9.6 on CentOS 7

I’ve been considering a project idea for Seneca’s partnership with Creative Commons. For that idea to work I would need a tool to create perceptual hashes from images that: Give true positive results when comparing images that were resized, and/or their colours changed. Give very few (near zero percent) false positive results. Too many false …

Continue reading Perceptual hash comparison: pHash vs Blockhash: false positives

From the CentOS FAQ: CentOS-6 updates until November 30, 2020 I was always suspicious about this claim, but I figured it’s based on RedHat, which is a serious company, and they can’t afford to screw with their customers too much. I don’t know how (if at all) this story is related to RedHat. The problem …

Continue reading Centos LTS my ass