add support for extra channels

[chrstphrbrns]

Fixes #100

Exports three new functions

• color -- extract the color component of an image, eg

julia> imshow(color(im));

• nchannels -- get the total number of channels from an image (color channels + extra channels)
• channel -- get the values from a specific channel (with the first N channels being color channels), eg

julia> imshow(channel(im, 5));

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 87.87879% with 12 lines in your changes missing coverage. Please review.

Project coverage is 92.36%. Comparing base (25cf338) to head (903fabd).

Files with missing lines	Patch %	Lines
src/types/common.jl	85.71%	5 Missing :warning:
src/types/widepixel.jl	28.57%	5 Missing :warning:
src/load.jl	87.50%	1 Missing :warning:
src/types/lazy.jl	50.00%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #159      +/-   ##
==========================================
- Coverage   92.68%   92.36%   -0.33%     
==========================================
  Files          13       14       +1     
  Lines        1121     1152      +31     
==========================================
+ Hits         1039     1064      +25     
- Misses         82       88       +6     

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[kimikage]

This is just a comment and does not block the merge, but color is one of the functions that ColorTypes exports. TiffImages users are likely to be using ColorTypes, Colors, or Images. At the very least, it would be good to have a note in the document.

[chrstphrbrns]

This is just a comment and does not block the merge, but color is one of the functions that ColorTypes exports. TiffImages users are likely to be using ColorTypes, Colors, or Images. At the very least, it would be good to have a note in the document.

What kind of a note? Julia already warns when two packages export the same symbol

WARNING: both ColorTypes and TiffImages export "color"; uses of it in module Main must be qualified

[kimikage]

It is not what it is, but where it is that matters.

in the document.

[tlnagy]

Sorry for the delay here, I was on vacation. I'm happy with the state of this PR (thanks @chrstphrbrns for your hard work here!). I'm going to release #165 as v0.10.1 and then I'll merge this PR into master to be released as v0.11.0.

[juliohm]

@tlnagy any update regarding this amazing PR by @chrstphrbrns ?

[juliohm]

It would be really useful to have this feature in place to solve #100

@tlnagy what is your plan regarding this PR?

[tlnagy]

Sorry, I've been swamped at my new job and haven't had much time for my Julia packages. I just released v0.10.1 and I'll release #165 as v0.10.2, rebase this branch, and if it all passes, this'll come out as v0.11.0

[tlnagy]

The segmentation fault with Julia nightly on MacOS + Arm64 is concerning. @chrstphrbrns any idea why SIMD might be failing there?

[juliohm]

@tlnagy is the failure on Julia nightly blocking? We are really looking forward to this.