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SPP vs ACR vs Image Viewer compared


Active Member
A geeky post from the watch guy . .

Since my main hobby isn't photography, I've been trying out various ways to convert my SD10 close-up watch shots to nice, sharp images. I rejected apps that need plug-ins to be installed, apps that have complicated UI's (e.g. command-line interfaces). I favor using just one app to open the X3F, process it and save it as a web JPEG. So I compared SPP 5.1, ACR 5.4/PSE 6 and (recently discovered) FastStone's Image Viewer. I used the same X3F HI res. source file and made three 1/2 size JPEGs, one from each app. The following is a comparison image made by opening those three JPEGs in Photoshop Elements, tiling them together and then taking and cropping a screen capture to make one image:


Please ignore the bluish color casts in SPP and ACR. For this test, I was more interested in image acutance than color balance. From the acutance viewpoint, the three methods are more or less equal. So which might I favor?

All my images are cropped, so that eliminates SPP for one-stop processing.

In terms of flexibility, the combination of ACR and PSE has much to recommend it, even though production is a tad laborious. However, my personality prompted seeking an alternative to "big business" .

For a non-mandatory $15 donation, Image Viewer is surprising good for what I do. The one thing that it's reviewers carp about is the lack of one-click white-balancing. But Image Viewer has the three hue sliders and, in combination with a screen app called ColorPix, balancing can be done. Big pluses in my view are the many choices for re-sampling (including two forms of the well-respected Lanzcos algorithm) and some interesting options for JPEG conversion . . .

The default option is "YCbCr" which meant nothing to me but it is an integral part of converting to JPEG format, apparently. The other option is "RGB" which I naively selected before doing some research. Here's a pic showing the result of both options, RGB at left:


Not much difference - until you go pixel peeping - RGB option (at left) looks like a Bayer image! . .


Not sure what the most correct of the two options is - I thought that conversion to the YCbCr color space was an integral part of the process of encoding a JPEG file, so what does the RGB option do for us, I wonder?

Anybody know for sure?

Best Regards,
Leaning back toward Adobe, sad to say . .

I was liking Image Viewer (IV) until I noticed that it doesn't tag jpeg outputs with a profile. This means that applications like browsers, other editors,etc don't know how to present my finely-crafted pictures. Not only that but Adobe's decoding of X3F files (how it looks in ACR) is as good as SPP's whereas IV's is a bit blotchy in the neutral color areas. Also, Photoshop Element's jpeg output files look a lot better for most of my images. And, finally, IV's jpeg output files show up as 0 bytes in size (even tho' they're not) on my XP machine, more often than I care for.

Had a look at IrfanView, but it seems like it only extracts the JPEG from the X3F file. Am I wrong?

Options - Properties - Plugins and uncheck "Try to load embedded preview image" - should work for SD9/10/14 cameras. (At least I hope so :))

Thanks for that suggestion, Arvo.

I found that selection, unchecked the box and it seems that I may have misunderstood how the program works. Does the check-box refer only to the preview thumbnail images? In other words, is the big image that is opened for editing always created from the RAW data (via a converter like, for example, dcraw), whether that box is checked or not?


Actually I don't know. I've never used Irfanview for editing. You need to experiment and compare resulting files.

Just tried - apparently my verison of Irfanview can't open SD14 files at all, when this checkbox is cleared. Maybe I have something not installed - SD14 decoding is almost identical to SD9/10, dcraw does handle them all.
IrfanView file comparison.

Actually I don't know. I've never used Irfanview for editing. You need to experiment and compare resulting files.
Yes, I did that, which prompted the question. The images (box checked or not) were the same on-screen but I haven't saved and compared in PSE yet. Maybe later, getting a bit tired of it today - you know how that goes!

Use SPP to convert the X3F to Tiff. Then use your favorite software program to do the rest of your post processing. Visit the Sigma Forum at DPReview.com for more information.

Thanks Jumus,

Lot of water under the bridge since I posted that in 2012. For an "important" image, I do follow your advice, I go SPP > TIFF > RawTherapee. For quick stuff, I go ACR > PSE > JPEG. For investigative work, RawDigger now opens X3F files! (mine anyway).


From those 3 images in the first posting, I like the most #2 converted from Adobe. Edge sharpness and colour is better than with the others. The number 6 is more contrasty, better red. The silver looks also better and more 3D...