Re: 'rgb2gray' undefined

[Carnë Draug]

On 16 May 2012 22:01, Nathan Armer <address@hidden> wrote:
> Yes, that worked, but now I'm getting "imfilter: first input argument must be 
> an image":
>
> octave:1> im1=imread('01.jpg');
> warning: your version of GraphicsMagick limits images to 16 bits per pixel
> octave:2> im2=imread('02.jpg');
> octave:3> uv=estimate_flow_interface(im1,im2);
> error: imfilter: first input argument must be an image
> error: called from:
> error:   C:\Octave3.6.1_gcc4.6.2\share\octave\3.6.1\m\image\imfilter.m at 
> line 6
> 7, column 5
> error:   
> C:\Octave3.6.1_gcc4.6.2\share\octave\3.6.1\m\flow_code\utils\compute_im
> age_pyramid.m at line 46, column 5
> error:   C:address@hidden
> cal_flow\compute_flow.m at line 93, column 21
> error:   
> C:\Octave3.6.1_gcc4.6.2\share\octave\3.6.1\m\flow_code\estimate_flow_in
> terface.m at line 90, column 5
> octave:3>
>
> The images are the first and second frames from the MIT test sequence 
> "table": http://people.csail.mit.edu/celiu/motionAnnotation/database/table.zip

Looking at the source (please look into
C:\Octave3.6.1_gcc4.6.2\share\octave\3.6.1\m\image\imfilter.m ),
you'll see the following:

65      [imrows, imcols, imchannels, tmp] = size(im);
66      if (tmp != 1 || (imchannels != 1 && imchannels != 3))
67      error("imfilter: first input argument must be an image");
68      endif

this are the lines that are causing your error. You should look better
into what you're giving to the function. Could you isolate the source
of the problem?

Carnë