How does one merge several jpg files into one file?

[mbye]

I need to upload 5,000 to 10,000 documents into some imaging software, but each page of these documents are seperate jpg files. I need to be able to QUICKLY or EASILY combine the files so that each jpg file contains many pages. The files eventually must be .jpg or .tif/.tiff or I cannot upload them properly. I need a way that can be quickly (a few seconds per file) replicated thousands of times. Thanks for your help.

Example:

Convert these files:
123001.jpg 123002.jpg 123003.jpg 123004.jpg
245001.jpg 345002.jpg

Into:
123.jpg (4 pages) and 245.jpg (2 pages)

 

[Speedo]

Using Photoshop or a similar program that supports scripts/automation would be about the only option.

 

[Turner]

Can't it be done on the command line? Something like copy image1.jpg + image2.jpg + image3.jpg? It's been forever since I've tried to do it tho.

 

[vbraun]

Can't it be done on the command line? Something like copy image1.jpg + image2.jpg + image3.jpg? It's been forever since I've tried to do it tho.

ImageMagick does this. http://www.imagemagick.org/

 

[mbye]

Thank you so far for the input. I have downloaded the ImageMagick and confirmed that it is installed correctly. Now, I am trying to figure out the proper command for an example below. Unfortunately, I lack any form of programming skills.

I went to the directory where the picture are located in command line (say C:\). My typing is in bold for the example: I want to make these three files '123001.jpg' '123002.jpg' '123003.jpg' into one new image '123.jpg'

C:\convert 123001.jpg 123002.jpg 123003.jpg -append 123.jpg

Unfortunately this shrinks the 3 pictures into the same vertical size that one picture use to take so they become too small. How can I keep the images the same size and just move on to the next page? Please help.