Qualify use of centered

[angusmoore]

centered is exported by both ImageFiltering and OffsetArrays. This causes issues, as both packages are using within, so the name is ambiguous. Fix by (1) explicitly calling OffsetArrays.centered (2) import rather than using ImageFiltering.

Assume this bug was introduced by OffsetArrays recently newly exporting centered (introduced here: JuliaArrays/OffsetArrays.jl#242)

For clarity, the problem this PR fixes is this (in a fresh environment, install Images and TestImages and run the example in the ImageQualityIndexes readme):

]st
[916415d5] Images v0.24.1
[5e47fb64] TestImages v1.6.0

julia> img = testimage("cameraman") .|> float64
noisy_img = img .+ 0.1 .* randn(size(img))
assess_ssim(noisy_img, img) 

WARNING: both ImageFiltering and OffsetArrays export "centered"; uses of it in module ImageQualityIndexes must be qualified
ERROR: UndefVarError: centered not defined
Stacktrace:
 [1] SSIM(kernel::OffsetArrays.OffsetVector{Float64, Vector{Float64}}, W::Tuple{Float64, Float64, Float64}; crop::Bool)
   @ ImageQualityIndexes ~/.julia/packages/ImageQualityIndexes/XJPki/src/ssim.jl:57
 [2] assess_ssim(x::Matrix{Gray{Float64}}, ref::Matrix{Gray{Float64}}; crop::Bool)
   @ ImageQualityIndexes ~/.julia/packages/ImageQualityIndexes/XJPki/src/ssim.jl:76
 [3] assess_ssim(x::Matrix{Gray{Float64}}, ref::Matrix{Gray{Float64}})
   @ ImageQualityIndexes ~/.julia/packages/ImageQualityIndexes/XJPki/src/ssim.jl:76
 [4] top-level scope
   @ REPL[11]:1

[johnnychen94]

Thank you so much for reporting and providing a fix for it.

OffsetArrays.centered is intentionally not exported to avoid this case but a recent deprecation has accidentally made it exported. JuliaArrays/OffsetArrays.jl#252 reverts this export.

But generally, we're planning to replace ImageFiltering.centered with OffsetArrays.centered so yeah we still want it.

The error seems unrelated, I'll fix it in a separate PR.

[codecov]

Codecov Report

Merging #36 (f2c2998) into master (bb4e7d1) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master      #36   +/-   ##
=======================================
  Coverage   98.72%   98.72%           
=======================================
  Files           5        5           
  Lines         157      157           
=======================================
  Hits          155      155           
  Misses          2        2           

Impacted Files	Coverage Δ
src/msssim.jl	100.00% <100.00%> (ø)
src/ssim.jl	100.00% <100.00%> (ø)

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[johnnychen94]

The rest of the test failure in the nightly builds is fixed by #37

Thank you again for opening this PR.