Need help with changing file type. Please?

[gardener]

I took well over 400 pictures at my granddaughter's Mesquite city championship soccer game last evening (they won 3-0) and when I downloaded the files to my computer, there were only 126 showing on the card and on the computer. What happened says I?
Started Image Rescue this morning before I left for work and the program recovered 550+ files. (Goes to show that even when you format the card, files may remain that aren't showing). ANYWAY... I have the 400+ images but can only open them in MS Windows and Fax Viewer. The format seems to be "THM" which I not only have never heard of, I don't seem to have a standard editing/viewing program other than MS WaFV that will open them and that includes PS Elements 4, DDP, and Zoombrowser.
It occurs to me that if I can change the format over to something else, I can then open and edit in PSE4 or DPP as usual but it also appears to me that the MS viewer program does not have a 'save as' function where I can change the file format.
Am I missing something here? Any advice on what to do now? I got my pictures back but I cannot do anything with them other than to open one at a time in the viewer and look at them. The program will also not let me scroll from one pic to the next as usual.
Any and all suggestions will be much appreciated as my computer skills leave much to be desired.Thanks for any help you may be able to provide...
Steve W

[Roy]

Steve, from what I can find out it looks like you recovered the thumbnails and not the jpg or cr2 files if raw. Have you written over the files on the card more photos?

[nyphotopro]

"THM" is a 3-letter dot extension that stands for "thumbnail." The good news is that frequently you'll be able to get your images back using the below procedure. The bad news is that sometimes all that's left of the image is a very small thumbnail of it.

If you are on a Windows-based computer, enable viewing file extensions and then change the extension to ".jpg" and you should be able to then open them with any image editor.

If you are on a Mac, you should be able to simply add ".jpg" to the end of a file and double-click. Whatever image editor is set to open JPG's should then open the file. If you perform a Command-I (get info) on the file, the info window should display and you'll be able to change file names and expose extensions otherwise hidden as well.

[gardener]

No, I've not erased the files or reformated the card yet so whatever is left on it is what I have to work with. Windows here so I'll try changing the file extension and see what happens.
Thanks Roy and Matt...

[suzyjazz]

Originally Posted by nyphotopro

"THM" is a 3-letter dot extension that stands for "thumbnail."

I always wondered what that stood for! The Canon 300D had files of this type, but I never looked at them.

I agree with what Roy says -- I don't think those files are going to be very useful. I hope it turns out otherwise, but if that's the case, it sounds like something went drastically wrong during/after the pics were taken. If they truly are JPGs I wonder why they just don't get saved that way? My 300D saved 3 files per pic (when shot in raw): a raw file, a small JPG, and THM.