[mythtv-theming] How would I create a vignette effect with fanart?

[Robert McNamara]

On Thu, Sep 24, 2009 at 7:17 AM, David Asher <asherml at gmail.com> wrote:
>
> On Sep 24, 2009, at 10:04 AM, Robert McNamara wrote:
>
>> On Thu, Sep 24, 2009 at 4:48 AM, David Asher <asherml at gmail.com> wrote:
>>>
>>> I'm interested in creating a similar effect as the vignette version of
>>> the
>>> fanart on thetvdb.com (e.g.
>>> http://thetvdb.com/banners/fanart/vignette/73739-34.jpg).  It seems like
>>> the
>>> best idea, however, is to download the full sized fanart and then use
>>> MythUI
>>> to create the vignette.  That way the theme can decide whether and what
>>> type
>>> of vignette to use.
>>>
>>> Could it be done just with a single imagetype using a mask file?  Or is a
>>> mask file only useful for cropping?  The mask attribute description is:
>>>
>>> mask allows a second image to be set to alpha-mask the original. This is
>>> a
>>> black and transparent image of identical size to the imagetype area,
>>> where
>>> black is visible and transparent will be masked. This allows for smooth
>>> edges and exotic shapes to your image. Masks cannot be resized or scaled.
>>>
>>> The usage of "alpha-mask" implies I could get varying level of
>>> transparancy,
>>> but the later portion of the description seems to imply only black and
>>> transparent are relevant.
>>
>> Why not just try it?
>>
>> Yes, a mask will work fine for your purposes.
>
> Because I like to overthink things...
>
> I guess I also don't understand image transparency.  In my head black is a
> color, transparent is an alpha level.  I guess my real question is: what
> attribute in the mask image implies 50% transparency?  A 50% gray pixel?
>  Something else?  Does the wiki mean opaque is visible?

50% opacity = a black pixel at 50% transparency (which will appear
gray, but is not gray)

Robert