InDesign JPG Compression vs Illustrator/Photoshop

Question

I am working on a website and need to put in a lot of images. For most images, I use photoshop. I create the correct size then export using "Save As for Web & Devices." This works great, but I need to display several small images in a grid format. What works best for me right now is to layout the images in InDesign and then export the layout as a .jpg. I realize I could use CSS to create a grid of the individual images and I also realize I could layout the document in Photoshop, however, for now I want to use InDesign.
Doing this got me thinking about the compression qualities of the different programs within CS (I am using CS4). From what I understand each program is built a bit differently. For example, the text engine in InDesign is different than the text engine in Illustrator (making working with text between the two programs seamlessly a total *****). I believe differences in the programs is the same for compression engines used to create formats like jpg? I've heard people note differences between Photoshop's Save As for Web & Devices and Ilustrator's Save As for Web & Devices so maybe that is the case? (I personally cannot tell the difference). I want to know what's underneath the hood of these programs and am having trouble finding this information.
So in short, what program does the best job optimizing images (jpg or png) for the web?
My guess is Photoshop, but this is a guess. If correct, why not InDesign or Illustrator? What compression engines do Illustrator, InDesign, and Photoshop use? Are there strengths and weaknesses? Why doesn't all the programs use the same compression engines?
I realize, in the end, if it looks good it works. But curiousity is killing me and I want a deeper answer.
Thanks!

Answer 1

ComputerGeekette,
I don't doubt for one second that this is indeed your experience and that you have settled into what I can best describe as a very degenerate workflow in order to get your job done under the conditions you describe.
Having said that, I must say that your experience and the fact that you believe that this is the best workflow you can achieve given the conditions is an exceptionally sad commentary on the state of the graphic arts industry in general and the printing industry in particular. The workflow you describe is a “lowest common denominator” workflow that almost guarantees that in most cases in which you have anything other than pure raster imagery to print, you will get results that are not optimal.
You should be able to use PDF/X-4 files as the means of passing artwork from your clients to you and then subsequently from you to your printers. Source files (i.e., native Illustrator, InDesign, and Photoshop files as well as assets such as imagery and fonts) should not be the currency of the realm here.
When I need to go “outside” to print (for anything my fleet of laser printers and wide format printers can't handle including offset printing jobs), I typically go and interview the print service provider and provide a sample job to print using a PDF/X-4 job with live transparency and color managment. If they cannot handle it in their normal workflow or cannot adjust to the twenty first century very rapidly, I move on to another print service provider. For better or worse, there are plenty of very hungry printers out there and at least some of them realize that unless they learn to deal with modern workflows, they will be history like the many thousands of other such printers that have gone belly-up over the last half dozen years!
          - Dov