[PD] Gem image analysis

[IOhannes m zmoelnig]

chris clepper wrote:
> On May 31, 2005, at 2:07 AM, IOhannes m zmoelnig wrote:
> 
>>> The last outlet is for the Z axis and, as near as I can tell, the code
>>
>> whatever "Z" means.
>> it definitely knows nothing about the z-axis in a 3dimensional space.
> 
> 
> The variable is labeled m_zOut throughout the source code.  It sure 
> looks like an attempt to map magnitude of the image brightness to the Z 
> axis to me, but then again I didn't write the thing.

but i did ;-)
don't know why i named it m_zOut though (i guess, because there was m_x 
and m_z and "z" seemed to be the natural 3rd variable)

> 
> I wasn't trying to contradict anything, but rather explain how the 

i didn't feel you where contradicting anything. sorry if i appeared to 
react that way.

> object came up with that value.  It's sometimes helpful to know that 
> sort of thing.

right and i am very thankful for the explanation.
i just thought that i should give my 2% too.


>> if you are not  sure, experiment with both and see what gives better
>> results
> 
> pix_background would come before pix_movement and strip away data which 
> could potentially cause false triggers.

which sounds totally reasonable to me.

> 
>> well, if he does "NOT want to TRACK anything" but just detect if there
>> is any movement in the image, your suggestion seems to be a bit
>> overpowered (nonetheless it should work fine)
> 
> 
> pix_movement + pix_blob give me enough false values that I recommend 
> using additional analysis to give more consistent results.  That's all. 

right.
now it's me who didn't want to contradict anything.

all the best
IOhannes