Speed and Memory Problems using Pictures

I have a set of macros that makes a list of image files from the network drive, and can display thumbnail versions of each image. Not surprisingly, it seems to be using a lot of RAM and sometimes bogs down.

In the macros, I've done a lot of the basic speed/memory optimization: avoiding loops, calling Functions once instead of multiple times, using "With <object>" blocks, and using "Set <object> = Nothing" when the object is no longer needed. That has all helped, but the spreadsheet itself seems to be slow.

When I scroll up and down, each thumbnail takes a full second to appear. My coworker says that when he swaps away from Excel -- into Outlook, for instance -- and swaps back, the spreadsheet is slow to reappear. (He says the CPU cylcles peak while this is happening.)

Are there any tricks to handling multiple images that would make it go faster and use less memory/CPU? Can I import the pictures "compressed" or something? Would it be faster if I displayed only the pictures that are in visible cells, and when I scroll, replaced them with the next screenful?


Thanks.

Have you tried resizing the original images to shrink their file sizes before loading them into Excel?
Does it make sense to create thumbnails images for each original, loading them into Excel and linking them to the larger images?

1) I believe you'd need to edit the images and resize them. Excel "resizes" by changing the magnification.
2) There might be a utility that will cycle through folder images, resizing them. I never searched for one. :\