Adds support for specifying kernels using StaticArrays

[zygmuntszpak]

Fixes #252

[codecov]

Codecov Report

Base: 78.62% // Head: 91.97% // Increases project coverage by +13.34% 🎉

Coverage data is based on head (7e2a965) compared to base (826df52).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #254       +/-   ##
===========================================
+ Coverage   78.62%   91.97%   +13.34%     
===========================================
  Files          12       12               
  Lines        1062     1657      +595     
===========================================
+ Hits          835     1524      +689     
+ Misses        227      133       -94     

Impacted Files	Coverage Δ
src/imfilter.jl	92.13% <ø> (+9.96%)	⬆️
src/border.jl	92.46% <100.00%> (+27.83%)	⬆️
src/models.jl	100.00% <0.00%> (ø)
src/kernel.jl	100.00% <0.00%> (+2.24%)	⬆️
src/ImageFiltering.jl	68.75% <0.00%> (+4.46%)	⬆️
src/extrema.jl	100.00% <0.00%> (+5.55%)	⬆️
src/mapwindow.jl	86.45% <0.00%> (+12.84%)	⬆️
src/borderarray.jl	93.33% <0.00%> (+13.67%)	⬆️
src/specialty.jl	100.00% <0.00%> (+15.38%)	⬆️
... and 4 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[zygmuntszpak]

@timholy Please could you take a look when you get a chance

[johnnychen94]

Sorry I missed this PR and the issue. Will check it ASAP.

[johnnychen94]

This is unfortunately a type-unstable patch: SOneTo{n} where n = length(interval) is runtime information.

IIUC, unless the image itself is also a SMatrix, we can't get a static pad, and thus we can't make it type stable.

The solution to support static array inputs might be converting it back to normal array and unit ranges.