Re: imwrite.m test failures

[marco atzeri]

Il 10/6/2013 6:52 PM, Andreas Weber ha scritto:
> Am 03.10.2013 21:46, schrieb marco atzeri:
> > testing latest devel
> > (changeset:   17540:b7aa1d726bcc)
> >
> > anyone seeing the same ?
> >
> > > > > > > processing /pub/hg/octave/scripts/image/imwrite.m
> >    ***** testif HAVE_MAGICK
> >   imw = randi (255, 100, "uint8");
> >   filename = [tmpnam() ".png"];
> >   unwind_protect
> >     imwrite (imw, filename);
> >     imr = imread (filename);
> >   unwind_protect_cleanup
> >     unlink (filename);
> >   end_unwind_protect
> >   assert (imw, imr)
> > !!!!! test failed
> > ASSERT errors for:  assert (imw,imr)
> >
> >    Location  |  Observed  |  Expected  |  Reason
> >     (1,1)         104          103        Abs err 1 exceeds tol 0
> >     (2,1)         184          183        Abs err 1 exceeds tol 0
> > ..
> >    (99,100)        96           95        Abs err 1 exceeds tol 0
> >   (100,100)       126          125        Abs err 1 exceeds tol 0
> > > > > > > processing /pub/hg/octave/scripts/image/ind2gray.m
>
> Hi Marco,
> cset: 0c6750ace8b4, test imwrite.m PASSES 10 out of 10 tests
>
> GraphicsMagick 1.3.16 2012-06-23 Q8 http://www.GraphicsMagick.org/
>
> MAGICK_CPPFLAGS = -I/usr/include/GraphicsMagick
> MAGICK_LDFLAGS =
> MAGICK_LIBS = -lGraphicsMagick++ -lGraphicsMagick
>
> Can you try
> octave> imw = uint8([0 100 200]);
> octave> imwrite(imw, "testA.png")
>
> and then in a shell
> $ gm identify -verbose testA.png
>
> I get:
> Image: testA.png
>    Format: PNG (Portable Network Graphics)
>    Geometry: 3x1
>    Class: PseudoClass
>    Type: grayscale
>    Depth: 8 bits-per-pixel component
>    Channel Depths:
>      Gray:     6 bits
>    Channel Statistics:
>      Gray:
>        Minimum:                     0.00 (0.0000)
>        Maximum:                   200.00 (0.7843)
>        Mean:                      100.00 (0.3922)
>        Standard Deviation:        100.00 (0.3922)
>    Colors: 256
>      0: (  0,  0,  0)     black
>      1: (  1,  1,  1)     #010101
> ..
>      100: (100,100,100)   #646464
> ...
>      200: (200,200,200)   #C8C8C8
> ...
>    255: (255,255,255)     white
>    Filesize: 69
>    Interlace: No
>    Orientation: Unknown
>    Background Color: white
>    Border Color: #DFDFDF
>    Matte Color: #BDBDBD
>    Compose: Over
>    Dispose: Undefined
>    Iterations: 0
>    Compression: Zip
>    Signature:
> 6f5c5c4f22b887737ef219b11c1e7f94faef02e50d985032538327b2bcd9a2ec
>    Tainted: False
>
> Until now it could be a problem with imwrite or imread, perhaps we can
> assign it to one of them.
>
> HTH, Andy

Q16 instead of Q8
GraphicsMagick 1.3.18 2013-03-10 Q16 http://www.GraphicsMagick.org/

therea are some slight differences in the gray depth

$ gm identify -verbose testA.png
Image: testA.png
  Format: PNG (Portable Network Graphics)
  Geometry: 3x1
  Class: PseudoClass
  Type: grayscale
  Depth: 8 bits-per-pixel component
  Channel Depths:
    Gray:     8 bits
  Channel Statistics:
    Gray:
      Minimum:                     0.00 (0.0000)
      Maximum:                 51143.00 (0.7804)
      Mean:                    25528.67 (0.3895)
      Standard Deviation:      25571.61 (0.3902)
  Colors: 256
    0: (  0,  0,  0)      black
    1: (  1,  1,  1)      #010101

    100: (100,100,100)    #646464

    255: (255,255,255)    white
  Filesize: 69
  Interlace: No
  Orientation: Unknown
  Background Color: white
  Border Color: #DFDFDF
  Matte Color: #BDBDBD
  Compose: Over
  Dispose: Undefined
  Iterations: 0
  Compression: Zip
  Png:IHDR.color-type-orig: 0
  Png:IHDR.bit-depth-orig: 8
  Signature: 
eaa4e546aa78466f45e563dbcbab6f26d66e96f2485b3e199d7b0e59c5f49775
  Tainted: False