I really like Display Fusion but it seems that your random number generator isn't very random ... I have it cycling through 812 pictures and see the same ones over and over ..... selecting Alphabetical fixes this.

I hope you don't mind me tagging along a bit? I think my question falls under the thread subject and doesn't necessarily need a thread of its own:

I read from an earlier post (from 2012) that the system for selecting images is supposed to be totally random, is this still the case? I have a fairly hard time believing it though. I have roughly 10 000 images to pick between my 4 monitors, and after adding 250 more images just yesterday I've been keeping an eye on the backgrounds. My images change every 8-10 minutes (depending on the monitor) and so far in the time I've followed I've there hasn't been a single time that at least one of the monitors didn't have one of the new images as a background. The majority of the time at least two of them have images from that latest set, and on several occasions all four have had them. I've noticed this behavior in the past as well, but now I've really paid attention to it. Looking at the numbers there should be a roughly 2.5% chance that an image from that set is picked, so with 4 screens I'd expect to see one every 10 or so changes. At the moment though it definitely feels like the chances are much closer to 10% for each monitor, if not higher, since I'm seeing them on half of the screens most of the time.

Note though that this is not a complaint, just an inquiry. I actually rather like the feature, you get to see your recent additions a lot after adding them, and with time (say a week or more) they seem to become more random again. Don't know if you've done it on purpose or not, but that's the way it definitely seems to work at the moment, might just be the limitations of random algorithms used showing up in this case. =)

EDIT: Point in case, I just copied 10 images in one folder into another one as well, and within the next 5 image updates 3 of them were loaded. Out of nearly 10 000 images. The favouring of recently added images is quite obvious. =)

The wallpaper random number generator/selection seems to be having a problem for me. I am seeing some of the same photos again and again. Much more often than would occur randomly.

While I am only using two monitors, I have a great many photos. Three main folders, each of which contain many subfolders, and many photos. Roughly 23 thousand photos in total. I have had this lack of randomness problem for some time, it is not a new problem for me.

I am using the latest Beta (6.0.1 Beta 1). I have disabled the image history in the Advanced Settings > Wallpaper section.

Hi Keith. I’ve provided DisplayFushion roughly 23 Thousand – that is (23,000) pictures to choose from in displaying my Wallpaper. My change Interval (minutes) is 3.00 on one monitor, and 4.00 minutes on the other monitor. With that Many photos available if DisplayFushion was truly using a Random selection I might occasionally see the same image twice or more in a short time. But not often.

Because I am regularly seeing some of the same photos over and over again (even after rebooting) in a relatively short time frame – this makes me suspect that DisplayFushion is NOT working with the roughly 23,000 pictures – but a much smaller subset.

I disabled Image History probably for two reasons.
One -- I suspected that DisplayFushion was choosing to display pictures from something much smaller than the 23,000 photos available. I was attempting to make all my photos available.
Two – I have DisplayFusion changing my wallpaper fairly often, and I have lots and lots of photos. I didn’t want to bother DisplayFushion with the necessary resources and horsepower to keep track of the previously displayed photos.

Just joining the conversation here.
I've got my desktop wallpaper settings set to 'load random images' and I've added some local folders on my computer to pick from, and set it to change every 15 minutes.
There's more than 8000 wallpapers in my gallery, yet I see the same pictures over and over again several times a week. Not just the same one, but lots of the same ones. If it was truly random there should be something like 41 days between repeats of a single picture (8000/2*15/60/24).
My laptop isn't rebooted much, I just leave it in sleep mode, so it doesn't seem to be related to some data that's lost on reboot(?)

The randomness has been an issue for over a year, but the function that was added a while ago which supposedly lists the pictures that have already been used so they're not used again seems to have helped a bit; when I add new stuff to the folders it doesn't take long for it to show up, but it still keeps cycling all the old ones as soon as the new ones have been shown.

I'm guessing either the randomness generator is badly seeded, maybe you're reusing a seed so it keeps repeating the same cycle (like putting in the current time, which repeats every 24 hours), or the output of it is truncated too much to select every possible file when the file list is really long, or you've tried to make your own generator without using an equation that avoids cycling the same number space (you shouldn't make your own generators, it's not an easy thing to do right).

Something is wrong with it, could you have a look at it, please?

Thanks Keith. I really enjoy the wallpaper features of DisplayFushion. As I have looked at this discussion of Random Wallpapers, here are some things for you and/or the programming staff to possibly consider. No reply is necessary, unless you just wish to. I know you have enough challenges and questions already.

1)What triggers DF to build/rebuild the entire list of images? Personally I just reboot my PC every day or so, but Tailen’s laptop isn’t reboot much, and he just leaves it (and presumably DF) in sleep mode. Does sleep mode cause a problem?

2)What would happen if someone had only a small number of photos/images and a relatively high frequency of changing the wallpaper. With the Image History option being used? For example 35 images, and a new wallpaper being displayed each Minute (1 Minute).

3)A variation of question 2) I set the Image History retention for 7 days, I have 5000 pictures available, and the change interval is set to One Minute, with the Image History option being used. I don’t reboot my PC, but just leave it running. After about (5000 pictures / 60 pictures in an hour / 24 hours in a day) roughly 3 and a half days all pictures would have been shown. At some point does DF really start to struggle to find an Image to Display?

It's working a lot better than before. However, I've disabled the 'store image history' option, and I've seen three pictures show up repeatedly within two days. So I'm guessing it's still not random enough?
If it was truly random, I shouldn't see the same pictures this often, even when it's not keeping track of the stuff I've seen already.

Did you change it so it's actually showing every picture in the added folders now? Or is it still using a subset?

Sorry to revive a year-old thread, but I'm using 7.2 pro, and I'm curious if these advanced settings ever got into the "main" release. I've noticed a lack of randomness too, and was going to try the "whole collection" option.

Thanks!

There have been a couple of threads on this topic and DF has come a long way during the past year on fixing the randomness (or lack thereof) problem. I have just over 100k photos in my wallpaper image library changing every 30-40 seconds on three monitors. If you download the newest 7.2 or 7.3beta, you will see a huge improvement compared to v6.

That said, it is still not perfect. One thing I've found is that the image history file seems to get whacked out after a while. I have my history set to expire after 30 days. Not sure how/what/why, but I notice an improvement in the randomness after I delete it (every couple months). I haven't pinpointed this, but it seems to be worse after I do mass deletes from my image library (when I run a duplicate image finder program). More of a feeling at this point.

The wallpaper image history file keeps the history per-monitor, so if you draw multiple monitor images all from one large directory, you could see image duplication but on different monitors (I don't think DF checks the history for every monitor when it is choosing, just the history for that monitor). In my case I have three parent directories, one assigned to each monitor, so I don't have this problem.

Also, as your image library grows you will undoubtedly acquire duplicate images. Every time I add a bunch of new images to my library, I run a duplicate image finder program. It will find hundreds/thousands of duplicates, which I then delete.

DF has made great strides on this problem, although there is still some selection bias.