Rotation operation is inaccurate

[myuanz]

b_img = ones(N0f8, (100, 100))
b_img = colorview(Gray, b_img)


mosaicview(
    b_img, 
    imrotate(b_img, π), 
    imrotate(b_img, π, axes(b_img)),
    
    imrotate(b_img, 179 / 180 * π), 
    imrotate(b_img, 180 / 180 * π), 
    imrotate(b_img, 181 / 180 * π), 

    nrow=2, ncol=3, npad=20, fillvalue=colorant"white"
)

Regardless of image size, black bars are at least two pixels in size.

Julia Version 1.7.1
Commit ac5cc99908* (2021-12-22 19:35 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
      "Manjaro Linux"
  uname: Linux 5.10.84-1-MANJARO JuliaImages/Images.jl#1 SMP PREEMPT Wed Dec 8 09:50:30 UTC 2021 x86_64 unknown
  CPU: Intel(R) Xeon(R) Gold 6226R CPU @ 2.90GHz: 
                 speed         user         nice          sys         idle          irq
       JuliaImages/Images.jl#1-64  1200 MHz   64345068 s      16198 s   16151708 s  1720339615 s     739238 s
       
  Memory: 991.7728500366211 GB (93890.00390625 MB free)
  Uptime: 2.83035374e6 sec
  Load Avg:  2.23  2.05  2.72
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.0 (ORCJIT, cascadelake)
Environment:
  HOME = /home/myuan
  TERM = xterm-256color
  PATH = /usr/local/sbin:/usr/local/bin:/usr/bin:/var/lib/snapd/snap/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl

(@v1.7) pkg> st
      Status `~/.julia/environments/v1.7/Project.toml`
  [c7e460c6] ArgParse v1.1.4
  [6e4b80f9] BenchmarkTools v1.2.2
  [336ed68f] CSV v0.9.11
  [82f2e89e] ClickHouse v0.2.1
  [150eb455] CoordinateTransformations v0.6.2
  [5789e2e9] FileIO v1.11.2
  [7073ff75] IJulia v1.23.2
  [82e4d734] ImageIO v0.5.9
  [6218d12a] ImageMagick v1.2.2
  [02fcd773] ImageTransformations v0.8.13
  [916415d5] Images v0.24.1
  [4138dd39] JLD v0.12.5
  [23992714] MAT v0.10.2
  [7eb4fadd] Match v1.2.0
  [b98c9c47] Pipe v1.3.0
  [91a5bcdd] Plots v1.25.3
  [438e738f] PyCall v1.92.5
  [6038ab10] Rotations v1.1.1
  [90137ffa] StaticArrays v1.3.2
  [731e570b] TiffImages v0.5.2
  [ddb6d928] YAML v0.4.7

[johnnychen94]

Nice catch. I noticed that you're using an old ImageTransformations version, here's what v0.9.3 produces:

For imrotate(img, pi) and imrotate(img, pi, axes(img)) it's working as expected. While for imrotate(img, 1.0 * pi) it is not:

img = rand(4, 4)
imrotate(img, pi) == imrotate(img, 1.0 * pi) # false

[johnnychen94]

Fixed by #155. In v0.9.4: