I found an excel spreadsheet table of NGC objects that should work. This will allow me to pull the appropriate field of view for each image.

I have come up with a formula I am happy with. Using the NGC spreadsheet and the apparent diameter values in that, I have been able to a customized query for each NGC object in the database. I am pulling the Red images from the DSS2r survey. I adjusted the size of the thumbnail based on the size of the object. I made the minimum size of the thumbnail 200x200 pixels the maximum size to be 1000x1000 pixels and the image content will be scaled to the size of the target object unless the object is smaller than 2 arcmin in which case the thumbnail will cover 2 arcmin for those objects. Basically, it scales linearly up until 10 arc min for 1000x1000 and after that, everything larger than that will be scaled down to fit into 1000x1000. It was a tradeoff between detail and file size. I think this will work out.
I am doing a pull of the 7840 objects now. If I like how they come out, I will try one additonal pull with RGB settings which will take 3 times as long to see if they come out any better than the first few attempts. After that, I will convert them to PNG format and crush them using pngcrush. At that point, I should be able to tar them up and send them to you for review. Please let me know if there is any additional information you would need from me.

I have completed all of the NGC object pulls and reduced their size with pngcrush. Theoretically, you should be able to unzip the archive to the $HOME/.local/share/kstars directory and have all of the NGC thumbnails available to you in the Observation planner. I put all of the duplicate objects into a folder in the archive call ngcdupes. I did not want to replace the 47 color NGC object thumbnails that were already included in the program, but wanted to have them in case they were needed. The zipped tarball of the images is 281MB in size. How would you like me to get it to you?

I have installed this on two of my machines and both seem to be working fine. If you can get me a CSV listing of all of the IC objects and their sizes in arcmin, I can do the same process for the IC catalog.

Sure, here is what I was able to make so far: www.dropbox.com/s/uachga3n5ii7ra0/ngcic.cvs?dl=0

Are the major and minor axis the apparent size in arcmin for x and y?

I have built scripts based on the major and minor axis values being the X and Y sizes in arcminutes. I have done a test pull of IC 10 and can confirm that the thumbnail works when copied to the $HOME/.local/share/kstars directory. I am going to go ahead and do the same run to grab and compress all of the PNG files for the IC list. I should be able to complete that tomorrow and upload both the NGC list and the IC list thumbnails to wherever you need me to send them.

This sounds very good. I have been working on improving the "what's interesting" view in kstars and could really use some images for Ngc objects. Larger than 200 and smaller than 1000 pixels per side would be good for that view. Somewhere in the middle (500ish?) would be very good. A download of all would be good but being able to programmatically download them would be good too.

I have the images automatically scalling between 200x200 and 1000x1000 pixels based on the objects overall size. I believe knro is going to incorporate this as a downloadable addon to kstars once I get it to him.

Here's an example of how NGC 2024 looks for me in Kstars now in the observation planner

Ok. Here is what the same object currently looks like in the whats interesting view on my computer now. My thumbnail probably came from google images, I don't remember now. But I am planning to make some improvements in the image downloader as a part of this upgrade. Good sources for images are important. A bulk download might be a good approach but if you have a good method/source for getting images, I could include that for people that want to download one or two but not all.

I can't get the what's interesting feature to work right on my systems. I am not sure what I am doing wrong, but I only see a blank screen on the right side there.