bugGNU Octave - Bugs: bug #54614, [octave forge] (image) wrong...


bug #54614: [octave forge] (image) wrong results of entropyfilt

Submitted by:  Avinoam Kalma <avinoam>
Submitted on:  Mon 03 Sep 2018 05:16:00 PM UTC  
Category:  Octave Forge Package Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Patch Submitted Assigned to:  None
Originator Name:  Avinoam Open/Closed:  Open
Release:  other Operating System:  Any

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Sat 08 Sep 2018 09:03:17 PM UTC, comment #2:

Thanks for pointing me related bugs, however, I found some other problems:

Checking entropyfilt, there are two problems in __spatial_filtering__.cc

The normalization of the histogram is wrong. Instead of

the loop should be

Another problem is in the transfer of data from the matrix:
It seems that the line

is wrong, and should be replaced by

(Can someone confirm this?)
This change affects also stdfilt, rangefilt, and ordfiltn.

Changeset attached, including relevant tests in entropyfilt.m

Please review.

(file #44959)

Avinoam Kalma <avinoam>
Project Member
Sat 08 Sep 2018 06:21:03 PM UTC, comment #1:

Please also have a look at file #39544 in my patch #9235 (and maybe bug #45088 as well). It deals with a bunch of filter functions at once, including entropyfilt.m. This patch isn't perfect (the results aren't Matlab compatible, yet), but it

  • fixes the call to spatial_filtering.cc
  • has a bunch of Matlab compatible tests for entropyfilt in it.

Some years ago, Carne didn't want to use this patch, because he preferred to rather change the code of spatial_filtering.cc directly (if I remember correctly). But neither of us has taken the time to rewrite my patch since then...

Note: I haven't checked if this patch (i.e. only correcting the call to spatial_filtering.cc inside of entropyfilt.m) improves the results on the sample date in comment #0.

Hartmut <hardy>
Mon 03 Sep 2018 05:16:00 PM UTC, original submission:




Avinoam Kalma <avinoam>
Project Member


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:

Attached Files
file #44959:  bug_54614_V1.cs added by avinoam (2KiB - application/octet-stream)


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    Follow 4 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2018-09-13 avinoam StatusNone => Patch Submitted
    2018-09-08 avinoam Attached File- => Added bug_54614_V1.cs, #44959
    2018-09-03 avinoam Carbon-Copy- => Added carandraug
        Carbon-Copy- => Added hardy

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