bugGNU Octave - Bugs: bug #48129, `imread` doesn't seem to read...

 
 

bug #48129: `imread` doesn't seem to read correctly

Submitter:  Luis Mendo <lmendo>
Submitted:  Sat 04 Jun 2016 05:45:40 PM UTC
   
 
Category:  Octave Function Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Duplicate Assigned to:  None
Originator Name:  Open/Closed:  * Closed
Release:  * 4.0.0 Operating System:  * Microsoft Windows
Fixed Release:  None Planned Release:  None
* Mandatory Fields

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Sat 04 Jun 2016 06:13:25 PM UTC, comment #4: 

Thanks, Mike. I should have seached before posting

Luis Mendo <lmendo>
Sat 04 Jun 2016 05:55:58 PM UTC, comment #3: 

Or rather it is fixed for this particular test image because the one color is red. It will not be fixed for other channels, as I'm reading the other bug report now. Still, it is identical to that bug report.

Mike Miller <mtmiller>
Group Member
Sat 04 Jun 2016 05:54:05 PM UTC, comment #2: 

Thanks for the bug report. I think this is a duplicate of bug #41584, which was fixed on the default branch. I do see the error you describe with version 4.0.2 but not on a development version of Octave. So the fix will come in a future 4.2 Octave release.

Mike Miller <mtmiller>
Group Member
Sat 04 Jun 2016 05:48:12 PM UTC, comment #1: 

Try this:

[x, map] = imread('http://users.wfu.edu/matthews/misc/jpg_vs_gif/testImage.gif');

The produced `x` is of type `logical`. I think it should be `uin8t` or `double`, so that `map` could be indexed by `x`.

Luis Mendo <lmendo>
Sat 04 Jun 2016 05:45:40 PM UTC, original submission:  

Try this:


[x, map] = imread('http://users.wfu.edu/matthews/misc/jpg_vs_gif/testImage.gif');
-verbatim+

The original image has three colors. I expected variable `x` to be of type `uint8` or `double`, so that the variable `map` could  indexed with it. But `x` is `logical`

+verbatim+
>> whos x map
Variables in the current scope:

   Attr Name        Size                     Bytes  Class
   ==== ====        ====                     =====  =====
        x         100x200                    20000  logical
        map       256x3                       6144  double


This doesn't seem to be correct, because color information in the image is lost.


Luis Mendo <lmendo>

 

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    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-06-04 mtmiller Dependencies- Depends on bugs #41584
    2016-06-04 mtmiller StatusNone Duplicate
        Open/ClosedOpen Closed

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