I've been experimenting with this for a while and am trying to find the best method.

I have a camera feeding images to a PD patch. A new image comes in say every 15 mins and I want to sum this image individually or layer/stack it on top of the previous image. So ideally; visually the background of the image stays the same, it is only movement or people within the image that is added each time. The best method I have used so far has probably been [pix_diff]

So image 1 loads into [pix_diff] left inlet. Image 2 loads into right inlet. I then take a snapshot of this, save as new image and load the new image back into the left hand side of [pix_diff]... another image gets loaded into right inlet etc. It's not perfect, the image inverts every second time around because of finding absolute difference between the photos.

Other methods I have tried:
[pix_mix] - the new info in each image eventually washes out over time as new images get added.
[pix_compare] - only lighter OR darker pixes are replaced. so not all new info is added to new image, looks messy and lacks continuity
[pix_composite] - similar to pix_mix - old info becomes transparent or washed out as new info is added
[pix_add] & [pix_subtract] causes whiteout & blackout

If I could figure out a method that finds all new info in the image and adds this. I'm sure it can be done, just my basic knowledge of gem and pd doesn't allow it yet!

Hello!

I am attempting to create a file name from two separate lists; to facilitate incoming pictures from a camera taking time-lapse photos. The incoming image is stored in a folder and can change between '0007.jpg', '0013.jpg' and '0123.jpg', just using those examples to display different formats. The main prob is setting up a [open $1( that can call these possibilities; the varying precursors 0, 00 and 000 cause the problem). It's just the way the camera indexes and can't be changed so I'm trying to deal with it in PD.

I've tried the following:

[000( [2 \
| |

|
| [symbol(
| |
[list2symbol]
|
[02 \

note my main prob: instead of result becoming 0002 as wanted the extra 00s are dropped to read just 02.

How do I keep the 0s in the resulting symbol or use an alternative method for what I'm attempting to achieve? This is just the first step, next step I will input the data into a [makefilename %s.jpg] that can will result in 0002.jpg

I hope this makes sense outside of my head!

Thanks.

Exactly Yeah it's been good fun so far, I'll attach what I've been working on to give an idea..

http://www.pdpatchrepo.info/hurleur/Sum_Images.pd

Looking at the [alpha 1] help example it appears to use the same technique for blending as [pix_mix]. This would work for 2 pictures but I don't think this blending technique works for multiple pictures because it averages between pixes and info eventually gets washed out and lost. i.e. if you have 6 pictures of a lawn; in 1 of the pictures a person stands on the grass, other 5 are just grass. Using this blending on the 6 pics - the result will be 5/6 grass, 1/6 (pretty transparent) person. I need the person to remain visible and not become transparent as more pics are added, if this makes sense. Which is why the [pix_diff] seems to work best for me so far. It gets the absolute difference between pixes rather than blending.

That does look complicated, I'm sure I can extract something from it though, thanks!

Hi domien, your answer probably works, I'm not sure how though... can you send a symbol through list2symbol? Doesn't it expect just a list?

I've since figured out a way to alter my camera's utility settings so it starts indexing the files begining 100.jpg. This is much easier.

Thanks for the response.