On 19 February 2010 05:20, Martin Nordholts <ense...@gmail.com> wrote:

> I don't think we should have two tools for this, rather one tool that
> does a great job

> Afaik GSoC is supposed to be a full-time undertaking, if you spend 30
> ours each week on other stuff it can be hard to be productive. If you
> think you can solve the task at hand despite this however, it will not
> be a problem in practice.

I intend to write the plugin as part of my MSc thesis, even if it is not
chosen as a GSoC project. In fact, I talked to my advisor and he got very
excited about the idea, so I believe that my initial estimate of 25~30h
could drop to 10~15h (probably even less during GSoC).

Regarding the quality of our approach, I have made a quick comparison and it
outperformed GIMP's tool based on SIOX for quite a few images (required less
user interaction for correction and produced equal or better results for
different types of images). So, if our method indeed proves to be a good
alternative and be accepted by the GIMP community, I would be more than
happy to implement it as an integral part of GIMP, even if it means doing it
for GSoC.

Our segmentation framework and the plugin idea work as follows:

 1) When the plugin is loaded the image is automatically pre-segmented and
the result is shown to the user.

 2) The user would then draw object markers selecting the regions which
compose the object, and inserting background markers when a region contains
both object and background pixels (those regions will be split independently
as near the object's border as possible).

 3) Then, our approach uses the markers to improve the automatic
pre-segmentation (by learning the color distribution and texture of the
object), to select the regions that compose the object, and to divide the
regions that need to be divided.

 4) Finally, the user may add/remove object and background markers to
finalize the segmentation by selecting/splitting the regions. This step does
not need to learn the object's properties.

 * Optional * 5) I am currently working to improve a tool for soft
segmentation which is applied automatically to the border of the
segmentation mask, and which may be interactively used on fine features such
as hair.

There are only three parameters that may be changed by the user:
 1) The number of regions which should be pre-segmented (usually a slider to
select between "less" and "more" regions)
 2) The percentage of the object's information that should be used (we
actually combine information learned from the object markers with color and
texture information from the image to achieve better results).
 3) Marker size and type (object/background).

Certain aspects of the framework may be changed or simplified to make it
even more user-friendly, such as the automatic pre-segmentation step and the
combination percentage parameter (50% usually yields good results).

 * Note: I can demonstrate our method if necessary *

I'd rather prefer that you used the GCC vector extensions:
> http://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html
Actually, that is what I currently use so there will be no problem.

Thiago Vallin Spina
MSc student
Laboratory of Visual Informatics
Institute of Computing -- Unicamp
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