View Full Version : Very quick mini-survey of batch file converters for MacOS X

04-12-2005, 22:08
All of us who own an R-D 1 and a MacOS computer are painfully aware that Epson gave us a bit of a shaft in the bundled-software department. For shooting and processing raw files, Windows users get both a Photoshop plug-in and a separate batch-processing application; Mac users get the plug-in only.

This made it difficult for me to shoot in raw format, because I tend to shoot a lot. Opening an entire session's worth of files one at a time, using the Epson plug-in (excellent though it is), often is just not practical. What I need is a way to do a quick conversion of a batch of raw files into a format that I can catalog and browse, THEN select the shots that are worth investing the time in opening and converting.

Until this afternoon I had thought that there weren't any MacOS X-compatible raw file conversion programs that could handle Epson's ERF format. But thanks to another post on this forum I learned about one, and that led me to a couple of other options. I thought I'd summarize my few hours' worth of learning to date for anyone else who might need a quick answer. Here's what I've found so far:

RAW Developer - sophisticated $70 solution

This full-fledged application from Iridient Digital (http://www.iridientdigital.com/products/rawdeveloper_download.html) is a powerful, serious solution. It handles ERF files three ways: singly; in small batches via a filmstrip-type browser; or in an automated batch process via a drag-and-drop window.

It offers a huge range of options for converting raw files, including white balance, tone, sharpening, noise reduction, and an option for auto-detecting 'hot' and 'dead' pixels that seemed to work well in my very cursory tests. You can try out a set of options on one image, then save the option set and apply it to a group of images in batch-processing mode.

Output formats include Photoshop, TIFF, JPEG and several other flavors. Two minor omissions that struck me as curious in this otherwise very thorough application: You can't save 16-bit Photoshop files (your only 16-bit options are TIFF or PNG) and there's no option for downsampling images, which would be convenient when you just need a quick way to make medium-quality files for a "contact sheet."

RAW Developer downloads as a demo version, which puts a watermark across converted images but isn't "crippled" in any other way, so you can give it a good tryout before deciding whether you want to invest your $70 to get a serial number that removes the watermark. I'm still undecided, but so far RAW Developer is looking good to me.

dcRAW-X - Limited but inexpensive tool

This simple but effective application is basically a graphical front end for dcraw, a command-line tool originally created by a programmer named Dave Coffin for decoding raw files on Linux computers. dcraw is so effective that its underlying code is used in many other converter programs (including RAW Developer, Bibble, BreezeBrowser, and even Adobe Photoshop's Camera Raw plug-in). But being a command-line program, it's not exactly convenient to use.

Enter dcRAW-X, available for download here. (http://www.frostyplace.com/dcraw/) This $15 shareware program provides an easy-to-use graphic interface for dcraw. The trial version is fully functional except that its batch processing is limited to three files at a time.

In my limited testing, dcRAW-X did its job well, but it has one deliberate quirk: The files it generates are linear, meaning that their tone curve hasn't been compensated for viewing on a computer monitor; the result is that if used as-is, the images usually look too dark. Although that's not a problem if you plan to open the images in Photoshop and fix them, it's a big limitation if you're just looking for a way to pre-screen and catalog your images.

Raw-format purists point out that linear files retain more of the original raw data and allow for higher-quality post-processing. That's true -- but if you have to open the files in Photoshop anyway to make use of them, why not just use the Epson converter?

DCRAW - the zero-cost solution

As noted above, the powerplant under the hoods of both of these converters is Dave Coffin's dcraw command-line program. Coffin distributes the source code for dcraw free, under the open-source General Public License, but using it requires a C-language compiler and the know-how to use it.

Fortunately, another helpful soul named Francisco Montilla offers pre-compiled binary versions of dcraw at his website. (http://www.insflug.org/raw/) The MacOS X download consists of two pieces: the dcraw program itself, and the 'instruction manual' pages for it.

Both of these pieces have to be installed in special places normally invisible to the MacOS X user -- but these places are easily accessible using the Finder's "Go to Folder..." command, and actually installing the files is simply a matter of dragging them into place. (If you want to try this and it isn't obvious to you, let me know and I'll expand this section with more specific instructions.)

Once it's installed, you have to run dcraw using the Terminal program -- which might sound intimidating if you've never poked at MacOS X's UNIX innards, but isn't really difficult. After opening a Terminal window, the first thing you should do is read dcraw's "instruction manual" by typing man dcraw. Text will appear showing how to control the program's simple but useful conversion options by typing switches -- letters after the basic command that take the form -x, where x is some letter that controls a switch.

For example, to tell dcraw to convert a file named myfile.ERF into 16-bit Photoshop format, you'd type:

dcraw -3 myfile.ERF (-3 is the switch that tells it to use Photoshop format.)

You can batch-convert a number of files by adding their names after the first one, and the Terminal has a little trick that makes this easier: just type the beginning of the command, then switch to the Finder, select all the files, and drag them into the Terminal window. The Terminal will add all their names in the UNIX path style the command needs to operate. Press the Return key and dcraw goes to work. It's even fairly fast.

As with dcRAW-X, the conversion is linear, so converted images will look too dark if viewed as-is. But for this price (i.e., free) you expect to put up with a few inconveniences -- so how I handled this was to batch-import my converted Photoshop-format files into iView MediaPro, and then use its batch-adjustment capabilities to reset the levels of all the files at once.

This step took only a few moments and gave me a catalog of files that, while they may not have been optimum quality, were plenty good enough to evaluate which ones were the best candidates for a more careful full-dress conversion.

Spartan as it is, dcraw has a few useful tricks. One is the -h switch, which downsamples every cluster of four pixels into a single pixel. Although not a high-quality approach, this method is very fast and produces a 'draft-quality' image that works fine for cataloging and evaluation.

Another capability that's especially relevant to R-D 1 users, given our recent discussions of 'hot pixels' at high ISO settings, is that dcraw offers a crude but effective method of mapping out pixel defects. If you make a text document in a specific format, name it .badpixels, and put it in the same folder as dcraw, the program will read it and patch the bad-pixel locations by interpolating data from the pixels around them.

Producing the document is a bit tedious -- you need to identify each bad pixel in Photoshop by its X and Y coordinates, then type those coordinates into a list -- but it's not really difficult, and in my limited testing it seemed very effective.


RAW Developer seems like a good choice for someone who wants a full-featured solution. It gives you a lot of control and produces files that are immediately usable as-is. Its main downsides are a somewhat cluttered interface and a non-trivial price.

dcRAW-X doesn't fit my needs very well -- I'd just as soon interact with the dcraw program directly -- but for someone who just needs simple linear file conversions and doesn't want to bother fooling with the Terminal, it could be $15 well spent.

Using dcraw directly is a bit inconvenient, but it's free, it does the job, and it offers some useful tricks such as the half-size option and bad-pixel mapping. Currently, I'm planning to use it while deciding whether or not I want to invest $70 on RAW Developer.

Special Free Offer: To make using dcraw a bit more convenient, I wrote an Applescript that lets me select files to convert and choose some of the basic options without having to use the Terminal. I've attached it so you can download it and try it if you want. Remember that you must install dcraw for it to work!

To use the script, download it and put it in your Library>Scripts folder, which will make it accessible under the Scripts menu in your menubar. Or, just double-click it to open it in Script Editor, and click the Run button. This will let you see how the script is put together, so you can change the options (or add other types of raw files) if you want.

If anyone has any other experiences or recommendations with MacOS X-compatible raw-file batch converters, I'd like to know about them, too!

04-13-2005, 05:49
Addendum: I thought of a couple of further points:

dcraw and EXIF data: One drawback to using dcraw is that it makes no attempt to retain your camera's EXIF data (capture date, ISO setting, shutter speed, etc.) Of course, the EXIF data is still in your original raw files -- but if you use it for cataloging or sorting, dcraw may not be the way to go. RAW Developer does transfer your EXIF information; dcRAW-X does not.

Being a cheapskate with RAW Developer: This gambit is a little skanky, but it occured to me that if you're only using your batch conversions for cataloging and selecting which images are worth careful, one-at-a-time conversion with the Epson plug-in, you could just as well keep using the free demo version of RAW Developer forever. It puts small red type in the center of the image saying it was made with an unlicensed copy, but the image is still good enough to evaluate.

Having experimented with the other software I can see how much work went into RAW Developer, and I hate to recommend stiffing the developers of their well-earned license fee -- but if you're sitting on a big pile of raw images and don't have a spare seventy bucks right now, this could be your interim answer.

04-13-2005, 07:07
Jim and all,
If you pay $3000 for a digital body and 2 - 3 thousand dollars for Leica lenses then $70 is a drop in the bucket. I am a software developer and my philosophy is it should be free to try out software but as soon as you are utilizing the software and it solves your problems you should pay for it. If it does not help you out then look elsewhere.

04-13-2005, 08:37
Re Raw Developer: Are there any serious drawbacks to saving in 16-bit TIFF, opening in Photoshop and making adjustments, and then saving as a Photoshop file, rather than being able to simply save it as the outset as a 16-bit PS file?

04-13-2005, 09:58
Jim and all,
If you pay $3000 for a digital body and 2 - 3 thousand dollars for Leica lenses then $70 is a drop in the bucket.

I agree that if software is worth using, it's worth paying for. (Isn't that pretty much what I said?)

On the other hand, if you've just spent all that, you may be broke and $70 is two weeks' lunch money!

(PS -- all my lenses are Voigtlanders and old Canon screwmounts.)

04-13-2005, 10:01
Re Raw Developer: Are there any serious drawbacks to saving in 16-bit TIFF, opening in Photoshop and making adjustments, and then saving as a Photoshop file, rather than being able to simply save it as the outset as a 16-bit PS file?

Not any technical drawbacks that I can think of, other than that TIFF files tend to be somewhat larger.

It just means that while in the midst of working on an editing project, you'd have three types of files floating around: your original ERFs, the "intermediate" TIFF files, and the final Photoshop files.

Of course, you could avoid that by using TIFF as your final format, if that works for you.

04-13-2005, 10:16
I found two more options for batch raw file conversion on MacOS X:

Silverfast VLT
Commercial application, price $99; limited demo available.
Developer website here. (http://www.silverfast.com/show/silverfast-dcvlt/en.html)

This is a "virtual light table" (image sorter) plus conversion utility. It has lots of automation features and options, but (as with Silverfast's scanning application) I found the interface unnecessarily confusing. It does preserve EXIF data in converted files.

Between the two commercial options, I'd pick RAW Developer over Silverfast VLT -- it gives you more direct control over the conversion process. But if you already use and like Silverfast's scanning application, this might be a good choice.

(Silverfast's high-end digital camera application, DCPro, also indicates that it supports ERF files -- but at $399, I wasn't ready to put that many drops in their bucket!)

Shareware application, price $20; time-limited demo available.
Developer website here. (http://www.hexcat.com/viewit/)

This is a slick little image viewer with export/convert capabilities and a nice MacOS Aqua interface (although I noted some interface nuisance glitches such as parts of the screen not redrawing correctly.)

The viewer has rating, scaling, and slide-show features. Converting lets you save in a variety of formats and allows scaling, but does not preserve EXIF data.

I'd pick it over the other low-cost option, dcRAW-X, because it produces ready-to-view, gamma-corrected files rather than "linear" files that require postprocessing. (Of course, if linear files are what you want, you'd make the opposite choice.)

Both ViewIt and dcRAW-X are well worth a look if you want a simple, inexpensive tool, don't need the power features of the commercial applications, and don't want to mess with a command-line utility.

04-13-2005, 18:31
There’s also a nice Mac shareware program called GraphicConverter by Thorsten Lemke. I’ve been using it for several years, though I’m not sure if the 11 RAW formats it supports include the ones needed here. The shareware fee is $35 ($30 without cd delivery).


Key features of GraphicConverter X/Classic:
• Imports about 175 graphic file formats***
• Exports about 75 graphic file formats
• Browser
• Batch conversion with additional actions
• Slide show
• Easy creation of optimized images for the internet
• Basic images manipulation
• Enhanced images manipulation
• AppleScript support
• Support for the special features of Mac OS 8, 9 and Mac OS X and optimized for G4 and G5
• Support of new technologies like the JPEG2000 format

*** Many digital cameras can create raw files.
The following formats are supported:
• CRW - Canon
• CR2 - Canon
• NEF - Nikon
• DCR - Kodak
• ORF - Olympus
• X3F - Sigma
• RDC - Rollei
• RAF - Fuji
• SRF - Sony
• PEF - Pentax
• MRW - Konica/Minolta

04-13-2005, 18:47
There’s also a nice Mac shareware program called GraphicConverter

Wow, It's still around. When I worked on Macs exclusively this was the goto application.

And, I found it to be very worthwhile. I don't know how it is now but back then It required only a small amount of effort to set up batch conversion scripts or actions.

If the script failed you had some indication of where the failure occured.

At $35 (Which I think is not much more than what was asked for back then) you won't feel like you paid a lot for a little.

04-13-2005, 19:53
There’s also a nice Mac shareware program called GraphicConverter by Thorsten Lemke. I’ve been using it for several years, though I’m not sure if the 11 RAW formats it supports include the ones needed here. The shareware fee is $35 ($30 without cd delivery).


It's true that this is a very useful application (although I personally don't use it because I don't like the interface) -- but I was surveying specifically converters that can handle the Epson ERF raw format, and when I made a quick check of GraphicConverter this morning, it appeared that it does not.

(There were quite a few other raw-capable programs, including some well-known ones, that also don't handle ERF. Since all of these use Dave Coffin's dcraw source code, and the latest version of this does support ERF, it wouldn't surprise me if many of them suddenly acquire this capability in the near future. Maybe ERF support will even make its way into iPhoto, the latest version of which supports several raw formats.)

04-13-2005, 23:48
Well I tried the viewit program and yes it does read the R-D1 files but it is buggy and the colors come out wrong in the viewer but not in the thumb nail viewer. I had it core dump several times on me. I would say to wait for the next rev on this one.

04-15-2005, 09:07
A couple of quick comments.
Weird things with ViewIt. It works on my powerbook (OS X 3.8) , 1.33 GHz, but on not my G4 OS X 2.8, 533; on the latter, I get an imcompatible file warning.

Good initial impression of Raw Developer, which I tried on the slower non-portable. Even though it says the minimum requirement is 1 GHz, it seemed to run just fine. And I like the interface, and was more easily able to get desired colours than with the Epson plug-in. I will play with the demo more this weekend, and then make a decision.