JuliaImages / JuliaImages/ImageView.jl

ImageView's imshow incorrectly displays HSV images?

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Dominant language
Julia
Stars
138
Forks
33
PR merge metrics
No merged PRs in 30d

Description

Hello,

the toy code below demonstrates the problem: a one-pixel green RGB image is displayed as green, but is displayed as red when converted to HSV:

rgb
hsv

# Activate a brand-new environment
import Pkg
Pkg.activate(temp=true)
Pkg.add(["Images", "ImageView"])
 
using Images
using ImageView

# Prepare one-pixel RGB image
x = zeros(RGB{N0f8}, (1,1))
x .= RGB(0, 1, 0) # green

imshow(x, name="RGB") # correctly displays green

# Convert to HSV
y = HSV.(x) # conversion seems to be correct,  HSV{Float32}(120.0f0,1.0f0,1.0f0)

imshow(y, name="HSV") # diplays red instead of green!

Information for the troubleshooting:

using(Dates)

today()
versioninfo()
Pkg.status()
julia> today()
2023-06-27

julia> versioninfo()
Julia Version 1.9.1
Commit 147bdf428cd (2023-06-07 08:27 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-14.0.6 (ORCJIT, skylake)
  Threads: 4 on 8 virtual cores
Environment:
  LD_LIBRARY_PATH = :/home/xxxx/.emacs.d/tree-sitter-julia/src/
  JULIA_NUM_THREADS = 4
  LD_ARGV0_REL = ../bin/vshd
  JULIA_EDITOR = vim
  JULIA_PKG_DEVDIR = /home/xxxx/juliadev
  JULIA_CONDAPKG_BACKEND = Null
  JULIA_PYTHONCALL_EXE = /home/xxxx/.julia/conda/3/bin/python

julia> Pkg.status()
Status `/tmp/jl_M9VHws/Project.toml`
  [86fae568] ImageView v0.11.6
  [916415d5] Images v0.25.3

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by running the reported one-pixel RGB-to-HSV example with Julia 1.9.1, Images v0.25.3, and ImageView v0.11.6, then trace the imshow entry point and its HSV display handling. Done means an HSV image with hue 120° is displayed green rather than red, with a regression test covering the example.

Written by the indexing model from the issue text.

Assessment

Tech stack
julia
Domain
data-visualization
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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