RAW workflow

[D. Tivin]

I've been trying to develop a user-friendly camera RAW workflow. I'm have a little difficulty when it comes time to latent prints being prepared for import into our AFIS. To the point: should the bit-depth and re-sizing (callibration) be done in (we use photoshop) ACR or in Photoshop? Our AFIS requires a resolution of 500ppi, 8-bit and gray scale.

Any input or samples would greatly be appreciated.

Lt. D. Tivin
West Chester, Ohio Police

[Neville]

Hi David
first I doubt AFIS will accept RAW, what we did was photograph in both RAW and JPEG mode JPEG is the working image; it just so happened that the way we have the camera set up in the lab it work out to be exactly the same size that AFIS required. We converted to grey scale then sent them via the network to AFIS, NEC were very helpful and as we were one their first customers to request this they probably were a bit in the dark themselves. Previously we had used a floppy disk. The set up for the camera was our most helpful thing, we originally decided on the lens, all the cameras carry the same lens for Macro, we photographed a ruler as a reference saved the image to a folder then went into AFIS opened the image on AFIS at the input terminal and also photographed the ruler with the AFIS camera brought up the two images on screen and measured them on screen images from both cameras. As I said we were very lucky they were the same. All photos are taken at the same focal point distance scene or lab. we use a clear tube on the scene camera to ensure that. Otherwise you need a scale and resize with Photoshop to get the required sized image at AFIS.

[D. Tivin]

Thanks for the reply. Our AFIS will only accept .tif images that are 8-bit. However SWIGIT guidelines suggest taking comparison photos in RAW. I was wondering if any of the image callibration, resizing or contrast enhancements are done in RAW...OR... would it be a better practice to edit the photo in photoshop.

[D. Tivin]

I forgot to mention that our overall workflow is similar to yours. The "finished" images are imported into our AFIS via a shared network folder.

[Neville]

Hi Dave
I think the words 'SWIGIT guidelines' gives a clue they are not law set in concrete, edit it in Photoshop. Anyway can you really tell the difference between RAW and TIFF on screen. If you print it to even the fanciest printer in the world it is no longer a RAW. I am a fan of RAW images and see it has its place when things get to court, on the other hand for day to day work JPEG or TIFF are fine so long as it is not compressed too much, or better still not at all.

[Neville]

Sorry I just realised it was TIFF files, no matter, no biggy except they are larger files.

[George Reis]

If you are making any adjustments to the image, most of them are best made at the native resolution and highest bit-depth. Once the print is as good as you can make it, then resize it, and then convert to 8 bits. At that point, re-evaluate the image to determine if any additional adjustments are required - it is possible that the resampling will cause a loss of sharpness and/or contrast, so a final adjustment may be needed.

I would also suggest that part of making a workflow is to build in efficiency - and for this, I would suggest an Action for the resizing and conversion to 8 bits. You can even run the action from within the Image Processor, which could make a very efficient workflow.

I hope this helps,

George

[D. Tivin]

Thanks George that helps answer some of my questions on how to proceed. I have also been experimenting with the Equalize command. I've read where the command is used to esxaggerate the contrast between pixels that are close in color. For gray scale images it seems to really make the ridges "pop". What do you think about incorporating this tool into my latent toolbox?

p.s. Are you going to come out with a new edition of your text for CS4?

[George Reis]

I'm glad that helped David.

Regarding Equalize - it's a great tool, and you should use it if you find it helpful, and you understand basically what it does and how it does it. There are other variations of equalize, including neighborhood equalization that can be very effective as well. Unfortunately, they aren't native in Photoshop, but you can find plug-ins like FoveaPro that include them, or separate applications such as ImageJ, ImagePro Plus, etc. that include these features.

As to updating my book. Thanks for asking, but I have no plans for an update in the foreseeable future. CS4 didn't have any significant new features to merit an update to the book (Smart Filters is the most significant feature in CS4 for forensics users). I would have liked to have included more on working directly with movie files with Photoshop in the book, but until there are more changes to make, I don't think there is a need for an update. When the time comes to make an update, I think I'll do more with additional software applications also - perhaps include a section on image management using applications such as Extensis Portfolio; more on Photoshop Plug-ins like Noiseware, FoveaPro, ClearID; and more on separate applications and utilities like ImageJ, Screen Capture Utilities and Video Players/Codecs, Image Registration tools, etc. If anyone has any ideas, please let me know - if I get a large enough list, maybe I'll look at doing this sooner, rather than later.

George