Re: [Motion-user] Masking issues - RPi 4

[Barry M. <bar...@gm...>]

Hi Roger!

I think I was overthinking your replies.  What worked here was taking a 
screenshot (png), opening that with GIMP and editing -- basically a 
black rectangle overlying the general fan area and white rectangles for 
the rest.  Save that as .xcf  (default for GIMP).   Have GIMP export to 
.pgm.  Copy the file to /etc/motion, edit Camera1.conf.  Restart Motion 
and enjoy not having '3-trillion' Motion files of fan rotations! <g>

Thanks!

Barry




> I never do a "new" image.  I always open and edit the image off the
> camera (from the snapshot motion option) that I collect 1x per hour,
> that way the size is always right.
>
> Then I export/save it from gimp as pgm.
>
> You can also use vlc and/or mplay to play one of the collected vidoe
> files from motion and see what size it tells you.
>
> On Tue, Jun 24, 2025 at 10:20 AM Barry Martin <bar...@gm...> wrote:
>>
>> Hi Roger!
>>
>> I always start with an image pulled from the camera and open that in
>> gimp..  It is kind of a pain to paint it black and/or white for the
>> mask but it also gives me a good idea of what moves a lot and needs
>> masked.
>>
>> Yes, got that far: I have a black and white pgm file with black in the area (and slightly beyond) where the fan rotates.  It's that second part ("Line 2") I need help figuring out  (see quote, below).
>>
>> Thanks!
>>
>> Hi Roger!
>>
>> You need to make a mask file.  Take an image from the camera, read it
>> into gimp, then paint everything black you want ignored, and white you
>> don't want to ignore and export it as a binary pgm.
>>
>> Created the mask file: 205_Mask.pgm.  Basically first time using GIMP -- heavily relied on an old lesson: save the file when have a correct step!
>>
>>
>> file should look like this:
>>
>> file gs2_mask.pgm
>> gs2_mask.pgm: Netpbm image data, size = 3840 x 2160, rawbits, greymap
>>
>> And have the same size as your camera image.
>>
>> This part I'm getting confused with.  Figuring:
>>
>>      Line 1:    Open the newly-created mask file  (so 205_Mask.pgm)
>>
>>      Line 2:    Ummmmm....  I'm thinking some sort of command line or check the boxes dropdown.  My camera's resolution  is set at 1280x720. so plug that in for size.
>>
>> Thanks!
>>
>> Barry
>>
>>