Re: imwrite.m test failures

[Andreas Weber]

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