[Gmsh] Detecting objects in a jpg image

[Rui Maciel]

On 02/17/2011 04:46 PM, Sebastián Miguel Giusti wrote:
> Hi,
>
> I am working with jpg image into gmsh. At this instant I need detect 
> (within gmsh) inside the image different objects or regions to 
> automatically create the corresponding "phisycal lines and surfaces". 
> After meshing the image, I need, from the output mesh file, the nodes 
> and elements that belong to each line and surface, respectively.
>
> Any can help me !!!
>
> Thanks,

As this question didn't received a reply, here are my 0.02€.

I don't believe Gmsh does that. Neither Gmsh nor any other program, for 
what is worth.

If you really want to import a mesh from a raster image, a possible 
course of action is to convert your raster image to a vector format and 
then, after cleaning up the generated vector image, develop a program to 
convert your vector image to any format Gmsh supports.

There are at least two problems with this suggestion, which are:
a) you must develop a program to extract meaningful geometry information 
from your vector images
b) you must be able to generate vector images in such a way that they 
can be consistently used by your vector-to-geometry program

As I don't believe that any of those problems has a feasible solution, I 
believe that the best answer for your question is that what you want to 
do is practically impossible. Therefore, probably it would be better if 
you found a different way to generate/import geometry information.


Hope this helps,
Rui Maciel