Image resize plugin

[mocchira]

Goal

• Able to reduce disk space by resizing images on the fly
• Reduce performance degradation as possible

  Todo

• Survey image resizing libraries
• Determine how to implement it (Erlang, C-Port, NIF ...)

[mocchira]

links related to image processing libraries

• http://www.vips.ecs.soton.ac.uk/index.php?title=Speed_and_Memory_Use

Results

• ImageMagick
  • [C] processing jpeg format files is good
  • [C] support lots of image formats
  • [X] can't processs files which include many pixels (more than about thousands x thousands)
  • [X] very slow processing png format files about 10x more than OpenCV's
• GraphicsMagick
  • [C] support lots of image formats
  • [C] can processs files which include many pixels which can't be processed by ImageMagick
  • [X] slow processing speed than others
• NetPBM
  • [X] can't processs files which include many pixels (more than about thousands x thousands)
  • [X] worst slow processing speed
• VIPS
  • [C] processing speed AND memory space efficiency are very good in case of relatively small files
  • [C] can processs files which include many pixels which can't be processed by ImageMagick
  • [X] lack of algorythms for image decimation.
  • [X] might be forced LeoFS to adopt LGPL License due to existing implementations in Header files
• OpenCV
  • [C] processing speed AND memory space efficiency are very good in any cases
  • [C] can processs files which include many pixels which can't be processed by ImageMagick
  • [X] No support GIF

[mocchira]

We will adopt OpenCV. GIF supports are set to relatively low priority.

• Exprimental implementations by C-Port
  • https://github.com/mocchira/resizerl

[mocchira]

• bench on Dell1950(core 8, png:jpg=1:1, C-Port)
  • 500x500 (pixels)= 400qps
  • 1000x1000 = 100qps
  • 2000x2000 = 55qps
  • 4000x4000 = 15qps
  • 10000x10000 = 3qps

[yosukehara]

We does not plan to implement `Image resize plugin', yet. So I've closed this issue. If we decided to start to survey it, we'll reopen this issue.