Re: Proposed Implementation for the Visual Magnifier Addition

[Matthew Brush <mbrush codebrainz ca>]

Hi,

Sounds interesting!

You could also write all of your video transformation/filtering code as 
a GStreamer plugin so it can be reused in other GStreamer programs.  You 
could then use Cheese's GTK+/GStreamer interfaces to control the 
plugin's properties.

Or, you could just whip up a simple standalone GTK+/GStreamer 
application in not very lines of code to create a GStreamer pipeline 
with your "magnifier" element in it.

I actually wrote a small program[1] for fun that serves a similar 
purpose after I saw this[2]. It's a standalone application rather than 
being integrated into/with Cheese/GStreamer (it uses OpenCV), but you 
might find some of the video-related code interesting anyway.

Cheers,
Matthew Brush - Random cheese-list lurker

[1] https://github.com/codebrainz/digimag
[2] http://petrahele.webnode.cz/news/assistive/


On 11/17/2011 02:55 PM, David Descoteaux wrote:
> To all,
>
> Greetings again from the Western New England University students. We
> have reached a proposed implementation for the visual magnifier
> functionality to Cheese based on the GNOME human interface guidelines
> and our understandings of Cheese and GStreamer. Attached is the
> completed Software Design Specification of our proposed implementation.
>
> Our project's dokuwiki on the SoftHum website can be foundhere
> <http://xcitegroup.org/softhum/doku.php?id=s:cheesemagnifier:project>.
>
> To Summarize:
> -We plan to add a new drop-down menu to the main window of Cheese
> labeled "UAC" that will contain the visual magnifier filters and red
> guideline switches.
>
> -The filters themselves would be implemented as new CheeseEffects
> (accessible only through the previously described menu if need be) that
> would utilize GStreamer to modify the image stream from the webcamera to
> the high-contrast foreground/background filters the customer requested.
>
> -The horizontal red guideline, we are certain that we would implment as
> a CheeseEffect as well. However, we aren't certain if priorities of
> effects, or layers, could be implemented from either GStreamer's
> documentation or Cheese's. As the line needs to remain above, or redrawn
> on top of any other applied effect we plan to implement.
>
> As far as we have been able to piece together from the documentation and
> code of both packages, we have this as our basis of thought:
> CheeseEffects utilize GStreamer pipeline filters and a few of the
> plugins (In the case of the "Dice" Effect there is a "dicetv" plugin
> under the gst-plugins-good package) to manipulate the incoming video
> feed from a webcamera. However, tracing through Cheese's code hasn't
> provided a source apart from an enumerated list of strings that mention
> a few effects, so these are all best guesses about how the effects are
> actually created and used.
>
> The private API within Cheese has been a massive boon to the project
> (Thanks, again Amigadave for telling us how to generate that), but we
> would like some confirmation as to whether or not this is how things
> actually work within the program.
>
> The proposed implementation can be modified if the ideas are either
> incorrect, or not in line with how the project is currently progressing.
> Any form of input or criticism is appreciated.
>
> Thanks in advance,
> David "Biomech360"
>
>
>
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