## Old Family Pictures

For Christmas I received a box of slides that had belonged to my grandfather. The slides were 35 mm taken between 1955 and 1961, in a mixture of black and white and color. I do not own a slide projector, and some of the film was starting to deteriorate, by yellowing or showing blotches where the emulsion had retreated. It was apparent that these slides would be much more enjoyable converted to digital, and so I scanned them. This entry is the story of that scanning, for the technical voyeur and for my own notes.

The first step was to determine the resolution at which to scan the slides, and possibly a lower resolution for the final scan. Usually when I scan photographs I try to scan at about the resolution of the original image–usually about the scale of the “graininess” in the image. If the graininess is smaller than the blurriness in the picture I would scan to fully sample the blurriness, but no finer.

There are some resolution choices to consider that do not require experimentation. Velvia 50, which has a reputation as an excellent film, indicates resolution typically coarser than 150 lines/mm (3,810 lines/inch). 150 lines/mm corresponds to an equivalent of about a 20 megapixel camera. A recent era camera like the Nikon D300 has a 12.3 megapixel sensor, which corresponds to a resolution of 119 lines/mm (3,030 lines/inch), after adjusting to make it 35 mm equivalent.

The following picture shows a portion of a color slide scanned at my scanner’s maximum resolution,12,800 samples per inch, followed by a resampled version of the same image at 2,133 dpi (1/6), followed by too coarse a scan at 1,067 dpi (1/12). Notice that the correct resolution is not far from a 6 megapixel camera, about the same as my Nikon D40.

The following picture follows the pattern of the color slide, but is of a black and white slide. The resolutions are the same as with the color slide.  For the small parts I have radically stretched the contrast.

#### Bit Depth

I scanned at 16 bit/channel (48 bit color) for most slides. The reason to do this is that the slides require some significant color processing. Most of the slides are severely overexposed, and typically badly yellowed. In truth, if I were to simply fix the exposure issues and deal with the yellowing it might be OK to scan with 8 bit/channel. However, it is not clear that this processing is the last these slides will see. While the final output of the process stream will be a JPEG (which is limited to 8 bit/channel) I would like that JPEG to be fully utilized so that future editing does not lead to posterization or banding.

It may be helpful to understand posterization, also called banding. The following picture shows an image with 8 bits per channel, or 16 million colors, then 256 colors, and then 16 colors. Obviously the 16 color version is totally unacceptable. The 256 color version is visibly worse than the 16 million color version, look especially at the reddish object in the lower right.

The following diagram shows the image and histograms at two stages of processing, one starting with a 16 bit/channel image, and one starting with the same image at 8 bit/channel. Notice how the histogram in the final section of the 8 bit/channel image has deep valleys between the peaks—effectively that histogram is showing banding. Because the banding is nearly invisible in the 8 bit/channel image I think I could reasonably scan at 8 bit/channel; however, it would not take much more processing to produce visible posterization in the image scanned at 8 bit/channel.  The only two operations performed on this scene are contrast enhancement using a “curves” tool and color correction using the “color balance tool”.

#### Corrections

The slides include a variety of flaws. Most of them are underexposed. Most of them have also yellowed with age. There are places on some slides where the emulsion has what appear to be crystals growing, and others where the emulsion has retreated from small sections.  The following picture shows dark spots in some areas which are the caused by this crystalline looking deposit.

The following slide has clear parts, where the emulsions appear to have retreated.  On most slides this is only near the edge and the best solution is cropping.  However, on some slides it affects a subject’s face and must be hand painted.

Color correction and contrast enhancement was performed with the “levels” or “curves” controls and the “color balance” tools. The results of those operations are shown on the following image.  The left-most frame is the original scan, which looks like a badly overexposed black and white picture.  The middle image has somewhat better exposure, but looks like a sepia toned image.  The rightmost picture is color corrected, and reveals that photograph was not actually black and white, but a color photo.  Note that this picture isn’t really worth saving due to the motion blur and subject matter, but it is revealing of the impact of basic editing.

In addition, the process of digitizing the image introduces dust motes and fibers, some of these dust particles are clearly visible in the frames above.  To control the motes and fibers I brushed each slide on both sides, brushed the light source, and cleaned the scanner bed between each scan.

Most mote correction was accomplished with the clone brush. This worked for any region where the pattern was consistent and broad, such as the sky, or on gravel. However, across people’s faces the clone brush did not produce very good results.

The fibers often crossed faces or fingers, or other hard-to-clone regions. The brush seemed powerless to remove the fibers too, though it was efficient at moving them. The dirtiest slides were scanned twice, with brushing in between. Then the slides were overlaid, masked, and the top slide’s dirty parts erased to reveal the clean slide underneath.

While the method is effective, it is also a pain. In addition to doubling the scanner time, it increased the processing substantially. The slides had to be registered very accurately for the method to work. This required careful positioning, and rotation. Both operations were agonizing due to my computer speed. For color slides it was nearly intolerable, as my software crashed when I tried to use more than one color 16 bit/channel layer.

For reference, to register two images you take the two scans and make them layers in a single image, then set the “blend mode” to “difference”.  Perfect registration will reveal a black screen.  The figure below shows the full image on the right, and the difference image on the left.  The white outlines tell that I don’t have the image exactly registered, perhaps the rotation is a little wrong.

The layers that comprise a finished product include the two “rasters” and the “mask”, as shown in the layers dialog below.

Except for some scripting to automate the resizing, that is all the processing I did.  May my example be of service.

## Focus Stacking and a Moth

We found this really neat moth on our porch several days ago. It had already departed. It was in immaculate condition, and seemed the perfect opportunity for some focus stacking effort. As usual I used CombineZM for the processing, and my Nikon D40 with el cheapo Phoenix 100mm f/3.4 macro lens. Combination of about 20 photos, if I remember accurately. Anyway, for those of you who use CombineZM, the produced the following was the weighted average method.

I will award 5 points to anyone who can identify the stacking artifacts in this picture.

## Canon MX850 with Canon Paper

I revisited printing with the Canon MX850 this weekend. I printed a 4-image collage on a sheet of 8.5×11 inch Canon Glossy Photo paper. I had the printer settings for optimization and enhancement disabled, since this gave the most accurate printing in previous trials. The results are shown below. Note that my scanner pooped out about 1/3 of the way through the picture—I presume not permanently—so the images aren’t exactly the same scale and crop.

There is, maybe, a slight reddish shift in the left frame, but it is quite good overall. This print will go on display at the office. For album use, the resolution of the professional print services is better, but for most uses the printer is quite good. For anything hanging on a wall, this is great.

## Vibrance

Photoshop’s Camera Raw tool, for importing RAW camera images, provides a really delightful little slider called “vibrance”. Paint Shop Pro does not. I read one post suggesting that vibrance was effectively increasing saturation on low-saturated areas. I decided this would be worth trying to emulate in Paint Shop Pro with some layer magic. The results are shown in the comparison image below. My previous posts show how lifeless this image is right out of the camera. In the comparison, the only difference between before and after is the application of pseudo-vibrance. Skin tones are pretty good, given how much increase in saturation is visible in the toy.

To do this in PSP, open your RAW (or other file). Then split channels to hue, saturation, and lightness, or HSL. Note that PSP can only do an HSL split on images with 8 bits/channel, so it will prompt you to reduce the color depth. Let it, but as soon as it has generated the H, S, L images go back to your original and “undo”—this will restore the original color depth.

After splitting to channels your screen should look a little like the following. The original is in the subwindow DSC_0006 and the channels are in Hue3, Lightness3, and Saturation3. You can close the Hue and Lightness window—we will only be using the Saturation window.

Return focus to the original image. Add a new adjustment layer, with type Hue/Saturation/Lightness. Crank up the saturation to 50 or so—well past the crazy level that you would never, ever, use in a real photo. The effect will be attenuated by adding a mask.

The layers palette will now show the background, and on top of that a Hue/Saturation/Lightness layer.

Change window back to the Saturation subwindow, select all, and copy. Jump back to the original window. Select the adjustment layer by clicking on it in the layers palette. Then “Paste Into Selection”, which will embed a mask into the adjustment layer.

You can now see a small black and white image of the saturation channel in the layer thumbnail.

That’s it. Adjust the saturation until it looks good.

# Benefits and Drawbacks

Compared to Photoshop, this process is definitely a hassle. I haven’t determined if it can be scripted, but I’m certain there are keyboard shortcuts to speed the process along. There are benefits, though. In Photoshop Elements, once you set the vibrance in the import utility you’re done. If you decide later that you want to tweak the vibrance you have to go back to square one. In PSP you retain the adjustability, at the full 16 bits/channel, and you can layer in other adjustments, like levels. Furthermore, you can change how the effect is applied by adjusting the mask. For example, you can apply curves to the mask layer to change which portions of the picture are affected. I think that kind of adjustment would be fiddly, though.

Final note: I may actually be turning up the saturation on more saturated sections, rather than on less. The effect seems to work however. I did try using the inverse mask, and that may result in pleasing images, though in this case the image looked flatter, not more colorful.

## Canon MX850 and Home Printing Foibles

I had no interest in printing at home due to early versions of a study that showed home prints would fade, run, and fail to impress in almost no time at all. That study was updated, and the result made it look like home printing might not be a waste of time.

Also, I was loaned a Canon MX850 all-in-one inkjet printer, scanner, and fax machine, along with some paper. My experience is that home printing offers an exciting way to spend the endless hours I had nothing else to do with. Yeah, I’m blogging now—leave the obvious inconsistency alone, please.

I printed my classic color test photo (see The Color of Software) eight times. I really only wanted to fiddle with color management, but I discovered the true thrill of home printing. My best results were quite suitable for a quick mailing to Great Grandpa or to pass around at work. To save you the bother and expense, do what your printer manufacturer asks: buy their paper and their inks, anything else is false economy.

Printer manufacturers work very, very hard to keep it that way.

The following montage shows scans of a selected area of all eight prints. A key follows, along with some detail blow-ups of the coarse and subtle problems I encountered.

All the variations were generated by changing printer settings or paper. AV stands for Avery paper (#include paper type and number). OM stands for OfficeMax paper.

• OM1: OfficeMax Paper, printer set to Photo Paper Pro, Optimize and Vivid enabled
• OM2: OfficeMax Paper, printer set to Photo Paper Plus, Optimize and Vivid enabled
• AV1: Avery Paper, printer set to Glossy Photo, Optimize and Vivid enabled
• AV2: Avery Paper, printer set to Glossy Photo, Optimize and Vivid disabled
• OM3: Glossy Photo, Optimize and Vivid disabled
• OM4: OfficeMax Paper, printer set to Glossy II, Optimize and Vivid enabled
• OM5: OfficeMax Paper, printer set to High Resolution, Optimize and Vivid disabled
• OM6: OfficeMax Paper, printer set to Glossy Photo, Optimize and Vivid disabled, color turned down to -25

In all the OfficeMax (OM) prints there is a glaring flaw, the ink pooled and made little color clumps. It looks dreadful. Many show banding. The Avery (AV) paper worked reasonably well, the color did not pool and the variations are in line with what I expect from turning on “vivid” and “color optimize” modes. To be fair to Office Max, their instructions suggest setting Canon printers to “transparency” mode. This mode is distinctly missing from the MX850 control; every choice available is shown in this next screen shot.

This is probably deliberate on Canon’s part, at least they have a financial incentive to do so. Transparency printing (or printing on high-gloss nearly impermeable paper) uses much less ink. Furthermore, non-Canon papers might work well. Maybe it is not a conspiracy, but quality is clearly not the only metric.

I attempted to approximate the effect of printing transparency by turning down the intensity setting to -25 (see OM6), assuming this would deposit less ink. It deposited less ink, but it also made the photo appear underexposed. Some puddling occurred on her lips even so.

There are different characters of problems as well. The following picture shows some trouble areas in relatively high resolution. The background is the best shot, AV2, which has fairly accurate color representation where generally the color looks almost as good as the print I got from MPIX (currently my favorite lab). The print of MPIX is overall much nicer, but that is due to the higher resolution and the quality of the paper. More on the paper later.

The OM1 inset shows the terrible ink pooling. The AV1 inset shows the deleterious effects of enabling “optimize” and “vivid”, at least on this picture. OM5 shows pooling and banding, though with as bad as the pooling is this might not matter. Finally, OM4 shows fingerprints, which I must have gotten on the paper before it printed. Since I was working with clean hands I can only assume that printing is quite sensitive fingerprint oils.

The papers are quite variable, and the quality of the AV prints was limited by the poor feel of the paper, which was waxy and easily scratched off in my hands. Under glass I doubt this would be an issue, but I’d certainly approach mounting this on paper with caution—frequent bending might cause flaking.

The OM paper was quite nice. Only it is incompatible with the printer, and as such is useless. Clearly home printing is an opportunity to burn lots of time trying to get good results from something that can be quite fiddly. I expect quality and utility would be fine when using the manufacturer’s paper. For the albums, I’ll keep ordering prints. However, I can see a role for a printer when you want something in a hurry.

## More Focus Stacking

This little fellow is a hatchling turtle carved from Phytelephas “nut”, which looks a great deal like ivory. Detail I want to capture includes the small spots on the inside of the egg shell (behind the turtle). He’s a trick to photograph because all three of his dimensions are about equal in extent. That means he takes a big depth of field to shoot if you are going to fill the frame. I put my macro lens on, and the best I can do is the next shot, which was taken just to show the scale of the turtle.

The shot with the coin was taken at f/22, in crummy light; the exposure was about 2.5 seconds at ISO 200. The depth of field is still not as large as I want, and in the original there is substantial blur—which is probably diffraction. The focus stacking result is much, much more pleasing. I used the brilliant combineZM software (free as in GPL) to assemble about 20 shots into the main picture. A sample of those shots is shown below. You can see the position change, which was due to my unstable platform. combineZM is doing an amazing job of aligning the images.

As you can see from the focus range on frame 9, I provided too frames for the first half of this set. I probably should have shot close to 40 images. I also think it would be worthwhile to be very careful in moving the inter-frame focal point. Finally, the defocus on the near components of frame 20 looks bad—it looks extremely non-Gaussian, and I suspect that is responsible for some of the artifacts I had to work hard to suppress. I hope to get my hands on a Nikkor AF-S 105 mm f/2.8 micro relatively soon, perhaps that will help…

With respect to reducing artifacts, the leader shot is actually a composite of two products from combineZM. Overall, the best shot came from the “Do Stack” macro; however, the edge of the shell directly above the turtle was blurry (circled below). The “Soft Stack” macro produced a crisp shell above the turtle; however there were odd looking artifacts (inset) all over the image. The final result I got by masking in just the sharp parts of the shell from the “Soft Stack” macro while leaving almost all of the image as the result of the “Do Stack” macro.

## Color (White) Balance

A friend of mine suggested my first two posts were pretty difficult to follow. To address that, this is the first in a series of posts which will ramble on about other interesting digital photography topics in a more accessible way. Feedback is appreciated.

There are lots and lots of tutorials on the net, so consider this a teaser—if you want details our good friends at Google will help.

In my order of importance, the technical aspects of taking a good photograph are

1. Focus-if your subject is out of focus you’re stuck. There is no way to post-process to fix bad focus.
2. Framing-cutting someone’s face off is also uncorrectable. Almost as bad is getting too much of everything else and not enough of your subject.
3. Exposure-though as long as you don’t underexpose or overexpose too much you can do some recovery in the computer. Flash can make this very challenging.
4. White balance-people should not look greener, yellower, or redder than they naturally are. Often this is correctable in the computer, but it is really fiddly—getting it right in-camera can save a lot of time.

The other stuff is compositional—are your subjects’ smiling, is motion blur minimal, are flash shadows tolerable, and is the view interesting. Good compositional skills are what separate a really good photographer from, well, me. This article is about white balance. Just because it is number four on the list doesn’t mean it isn’t important. To get a feeling for just how important it is, look at the collage below—which shows the same picture rendered with a variety of white balance settings.

These pictures were shot inside my light box (a bucket) under natural light. In the custom setting I manually evaluated the white balance. I shot this picture in raw, and then applied the color corrections in Paint Shop Pro. This might mean the color casts are the opposite of what would be seen if I shot the picture in the claimed light with the wrong setting on the camera.

Color can be subtle, because although it is absolute in objects it is not absolute in perception—the proportion of colors an object reflects doesn’t change, but the apparent color certainly does. Our eyes and brains do an amazing job of figuring out what the true colors of objects are, even though the light can vary from, for example, the yellow of a sodium vapor lamp to the cool white tones of a fluorescent tube. Our brains can do this by processing cues from the environment around the things we’re looking at.

Cameras, however, capture a scene. The environment surrounding the scene is not recorded by the camera. Because of that we draw the color cues from the area we are in when we are viewing the picture, not the area the scene was in. In order for the colors in a picture to look good to us the camera (or post-processing) must render the neutral colors in the scene as neutral colors in the image. In other words, the camera has to remove the effects of weird lighting.

Generally your camera does an amazing job of compensating for the color cast of the scene lighting. With white balance set to “auto” most cameras, including my Nikon D40, Canon S2IS, Canon G3, and Canon SD100IS all do a fantastic job—usually. They don’t always, though.

I speculate that a camera’s white balance compensation works by having the camera select the most neutral portion of the image and assuming it is completely neutral, to first approximation. That is, the camera assumes any color cast in the most neutral parts of the image is due to color cast in the lighting, and it compensates it out. Experience has told me that camera processing is somewhat more complex; however, I find this model works well at predicting when I will need to be careful with colors.

When I’m shooting a scene with nothing neutral in it, I’m sometimes better off with a manual white balance setting. This happens a lot when I put my baby on a dark blanket—which I do sometimes to get a good contrast.

# Shooting for Good White Balance

The best choice about nine of ten times is to leave your camera in auto. If you fiddle with white balance settings it is just a matter of time before you leave it in some weird manual mode just when Baby is doing something cute. And then Baby is forever remembered doing something cute while being green.

Sometimes, though, you want perfection. Then the best bet is to set your white balance to “custom”. Custom settings work by having the photographer place a neutral object at the site of the subject, and then taking a picture (in the custom evaluation mode). You can buy special neutral cards to carry, but I’ve had excellent success with just a plain sheet of paper—which I carry folded up in my camera bag.

Be creative in a pinch. I once saw a TV cameraman pull one leg up and bend the camera down to his ankle to set the white balance on his sock.

# Two Lights

It happens pretty often that I have two sources of light. Most commonly there is an ambient light, fluorescent in the kitchen, natural near the windows, tungsten/incandescent in the dining room, and the flash. These sources sometimes come from different directions and light different parts of the scene. On the left of the picture below you can see the color comes from the room light, and on the right it comes from the refrigerator light. This picture doesn’t suffer for it, since we would see it as entirely normal. If the color came instead from the flash, however, this effect would be very awkward looking.

I don’t have a way to fix this kind of error, except to avoid it in the first place. If you have time to set up you can put compensating gels over the flash (which works really, really well). Alternatively, you can try to find an orientation that minimized the effect. If you’re me, and you’re photographing people, you just live with the bad color balance. Except for portraits, and then I use gels, manually set the white balance, and maybe shoot raw just in case. Raw is, generally, more correctable.

## Focus Stacking, First Stumbling Steps

Edit: 2009/01/30, evening.  After much searching I relocated an incredible site I had encountered before.  Charles Krebs’ work is really, really, incredible.  I was motivated to explore focus stacking after seeing image 29 in gallery 8, which I believe was produced with stacking.  Dig around his page, it is really awesome.

— Original —

I ran into the technique of focus stacking not long ago, and have been itching to try it since. I haven’t found good subjects, but I took a first stab this morning. The results of some of workers with this technique are absolutely mind-blowing. For some of my favorite work on the net, see http://www.janrik.net/insects/ExtendedDOF/. My example is of a small natural turquoise from a local mine. I used very poor stabilization, and I believe that has resulted in the artifacts at the far edge of the stacked frame. Nevertheless, this is very promising. Now if I can just find some interesting subjects.

My shooting setup for this, by the way, is crapulent to high orders. I use a bucket on a trashcan in the sun as a sort of lightbox, and a precarious tripod to shoot. The tripod was the source of my instability issues, but the trashcan certainly didn’t help. The bucket is not quite as good as the Lambertian integrating sphere I’d like, but it is rather more affordable.

## Color Management – Reprise

I noticed that what I included in my post Introducing… does not look the same on my monitor as it does on my friends’ monitors. While I expected some of that, I observed that the effects of interest were not at all visible, particularly the posterization. To solve that, here’s a quick comparison, done by taking a photograph of my monitor. In the left photo I have color management on, but the mode is set to “display”. The right photo is set to “proof” mode, with the output device emulating the Costco glossy prints. See Dry Creek Photo for a variety of lab profiles.

# Philosophy of Use

The basic tasks I’ve needed to perform on digital photos since my first digital camera (a Canon G3, may it rest in peace) are:

• orientation flipping
• cropping
• white balance correction or adjustment
• straightening
• communication to friends, family, work peers (by email or Web host)
• printing, for albums, sharing, my lab notebook, or display

For several years I resisted photo annotation tools, which let you add text tags or captions to pictures, because the annotations were stored in proprietary non-portable databases. Image metadata formats, particularly IPTC, can carry captions, tags, and useful context details. Now that IPTC is widely supported, the picture files can carry this metadata without external databases. It is a compelling feature.

I used to organize my pictures in date folders, typically the date of transfer from the camera. All the pictures I shot on Christmas vacation ’07-’08 might get uploaded on January 3, 2008. The pictures would be stored in a directory with a name like 20080103, a format I love because it lists chronologically when sorted alphabetically. If I needed to edit pictures I would process them in GIMP, which has supported cropping, flipping, contrast, and straightening reasonably well for many years. Modified versions of the picture would be saved with some indecipherable name, like dc021_m2_sm.jpg, which might stand for “2nd modification, resized smaller (sm) for upload to web”. As a process, this was the pits.

In the last year my needs have grown, due largely to lessons from shooting with a digital SLR.

# Shooting Raw

I’ll forego jokes about naked photographers. I started looking at more advanced editing software because some prints I ordered had dreadful color issues. I had the idea that the color problems might have been caused by some contrast stretching I performed in Picasa, or even that the image exceeded the dynamic range of the camera. Dynamic range issues in a camera can be treated three ways.

• At the shoot, if saturation is the issue, then underexposing a little can improve the shot. If the scene is very high dynamic range, then the dark areas may be clipped on the low-exposure side. Even if they’re not clipped, the signal-to-noise ratio in the darker areas may result in noisy regions of the photo. Noise removal software can sometimes help, but I regularly shoot conditions where there is clear loss.
• Shooting camera raw preserves the full dynamic range of the camera’s sensor, which might be 12 bits per channel instead of the 8 bits per channel available in a JPEG file. Postprocessing the raw file could potentially allow level compression to provide a better JPEG than the camera’s processing.
• Bracketing exposure and then combining in software can effectively enhance the dynamic range substantially. Some packages allow combining bracketed shots to get enhanced dynamic range. Normally I can’t shoot with brackets since my subjects are frenetic, so bracketed-shot combining is more of theoretical interest than practical.

This implies a few requirements for photo-editing software. First, it must be able to work well with raw images. In particular, I must be able to apply “levels” functions or “curves” functions to images containing the full raw dynamic range. In other words, those functions must work on 16 bit per channel images. Secondly, raw import of my camera’s format must be supported. Thirdly, combining bracketed images should be supported—though this is not a strong requirement.

Postprocessing raw files is tricky. You really don’t need an entire lossless file at 16 bits per channel for cropping, rotating, touchups, or most editing. However, for adjusting levels, contrast, or colors a full 16 bits per channel is a good thing—especially if you have a picture with really dark shadows and really bright highlights. Your tools must also be able to read your camera’s raw file format—for my ancient camera this is easy, but people with newer cameras sometimes discover that their files don’t import.

It turns out that my print issues had nothing to do with poor editing or limited dynamic range of the picture, and everything to do with color management. More on that later.

# Tools

Consider that you might solve all your problems with photo management by acquiring software. Here are three approaches that might seem reasonable.

## Free

For advanced editing use GIMP, which is very capable editing software. For downloading from the camera, managing photo collections and albums, uploading to the web or printers, and emailing Picasa is really very good. You might even consider just using GIMP for editing. Newer operating systems provide sorting and searching of EXIF data.

# Cheap

For well under $100 you could get Adobe’s Photoshop Elements or Corel’s Paint Shop Pro. These include picture management systems, sophisticated editing capabilities, and some limited uploading or emailing capabilities. ## Expensive For$250 to $300 you could buy Adobe’s Photoshop Lightroom, which is an extremely sophisticated software package. I suspect it has the same uploading and emailing capabilities as Elements. Of course, Lightroom costs nearly as much as a new Nikon 35 mm lens. ## Really Expensive For something over$650 you can get what would seem to be the acme of photo editing tools, Adobe Photoshop CS4. I didn’t even bother demoing this, so I can’t comment on its photo management or distribution capabilities.

I compared some of the preceding applications for my specific interests. What will work for you depends a great deal on what you want to do. My baseline before getting interested in raw image processing was Picasa and GIMP. The rest of this document looks at some of the capabilities I consider important for some of the packages I just listed. To be fair, I’ve spent enough on camera equipment this year that \$200 software package looks really profligate—so my emphasis is on free or cheap options.

The simple truth is that I love Picasa for almost everything. Here’s why:

## Nuisance

To my stark staring amazement, PSE7 actually pops up little bubbles containing advertisements while you’re trying to work. I don’t know what is required to turn this “feature” off, but to get this in purchased software is intrusive, irritating, and offensive. Be prepared for an astonishing level of rage if you use this software.

## Email

For email I use Google’s gmail, and Picasa’s email button works flawlessly with gmail. PSE7, PSP, and Picasa all support email through MAPI clients like Microsoft Outlook or Exchange. I have earned a burning hatred of Outlook and Exchange through many years of use. For a web-side gmail user, Picasa is the only choice.

For uploading to print services, Picasa is very simple. I select the photos I want to upload, and use one of the myriad pre-configured services, like CVS, Walgreens, Winkflash, Snapfish, Ritz, Kodak, Shutterfly, or one of about a half dozen others. This is distinctly different from PSE7, which offers only Shutterfly, and PSP which offers only CVS.

## Captioning

Captioning photos in all three applications results in text being stored in the “Description” component of the IPTC block. In Picasa and PSE7 captioning is trivial—just click the “caption” line below the picture and type. Captions in Picasa and PSE7 appear below the picture in the file sorter mode. In PSP captioning requires clicking the image, and then scrolling down in the context pane on the right. You cannot tell which files have been captioned except by clicking each one (or possibly with a search).

In short, PSE7 and Picasa offer similar interfaces to captioning. PSP supports both tagging and captioning, but with substantially less convenience.

## Tagging

Tagging in all three is accessed with a click. In Picasa tagging is accessed with a click on the little tag icon, which opens a dialog where you type the tags in. Auto-completion offers suggestions as you type, based on previously entered tags, which makes this painless. PSE7 tagging is richer, but I think harder to use. Tags are created and associated with a group, for example “people, friends” or “people, family”. This is tedious, and the categorization of the tags is not stored in the file. PSP offers simple text entry of tags, without auto-completion, categories, or even commonly-used tag lists. Tagging many files in PSP would be agony, but the interface is present adding or updating a few tags.

Historically I haven’t used tagging, but the ability to at least identify the subjects in the photo is compelling.

## Raw Import

Import of camera raw files, in my case Nikon NEF from a D40, is supported in all three packages. There is no on-import control in Picasa, but it reads and imports the files without trouble.

Basic edits are well supported in Picasa, including satisfactory white balance, contrast enhancement, straightening, and cropping. Naturally PSE7 and PSP are extremely capable editing tools—far more so than Picasa. In a shootout of the file sorting and sharing capabilities Picasa is, without question, leagues ahead of PSE7 and PSP. Why consider a non-free package like PSE7 or PSP at all, if Picasa is so capable?

Remember that my journey started with color problems in a print. The final, and perhaps most important requirement, is that I be able to soft-proof pictures before I have them printed. Soft proofing is the process of approximating the appearance of the printed product on the computer screen.

# Raw handling

The above picture is a composite of JPEGs produced by all three programs and the camera, all using program defaults on import. None of them are dreadful, but they are all very different. I chose this shot for demonstration, despite its awful composition, because it has a huge dynamic range. The black of the dog (Angus) next to the white of the fence in the sun has proven to be a very, very difficult shot to get well. The white of the fence is “blown out” or totally saturated.

If I spend some time and try to tune each import to get effects I want—such as details of Angus and relatively vibrant colors—I get the following.

The differences are still noticeable, but not huge. I like the PSE7 version slightly more (and it was easier to get), but the intensity of the colors is a little too high. The saturation should probably be somewhere between the PSP and PSE7 versions. Probably the take-away point is that you can get virtually anything you want the PSP, but there will be a few more steps than in PSE7 and a little experience required.

## Picasa

Picasa imports my raw files without trouble. There is no active control over the import process. I assume that Picasa applies corrections for color and white balance, and any sharpening automatically. I also assume that the working bit depth for Picasa is 8 bit per channel, since modifications to a raw file are saved as JPEG images. While this makes Picasa capable of using raw images, it offers essentially no advantages over shooting JPEG.

In general the images Picasa imports are washed and look distinctly desaturated compared to the JPEGs produced by my camera.

## Photoshop Elements 7

PSE7 can import my camera’s raw files. Indeed, I really like the PSE7 raw import tool. The tool, like most, provides adjustments for sharpness, brightness, white balance, and saturation. In addition, it includes an adjustment for the enigmatically named “vibrance”. Vibrance is a really wonderful control; it can give images from my Nikon D40 the kind of rich colors you get from a Nikon D300, without the improbable skin tones that come from simply cranking up the saturation.

However, PSE7 has almost no capability with 16 bit per channel images. I can understand why rotations, touch-ups, and so on are not defined for 16 bit per channel images, but I can see no excuse for leaving out color and light manipulation tools. Levels, curves, hue, saturation, and value adjustments must be defined for 16 bit per channel operations, or I get very little editing capability.

## Paint Shop Pro

PSP imports raw images without trouble, though there is no special raw import tool like PSE7 provides. However, almost all operations are defined for 16 bit per channel images, including crop, rotate, sharpening and so on. All the effects available in the PSE7 raw import, except Vibrance, are available in PSP, except that they are not located in a single palette convenient palette. On the other hand, PSP can perform the levels, curves, and color correction operations on the full 16 bit per channel image, making it particularly useful for manipulating raw files.

# Color Management

To see why color management can be so important, please see my article Introducing….

The picture shows screen captures I took using PSP with color management off, and with color management on, in “proof mode” below. The bottom picture represents quite accurately all the problems I observed in the prints I received.

Digital images represent colors with numbers, which must undergo transformation into control signals for devices like monitors and printers. Image files most commonly represent colors the sRGB or aRGB (Adobe) color spaces. A printer, or online developer might have a totally different color space defined. The printer or developer uses their devices profile, along with some kind of optimization protocol (called an “intent”) to transform your image into control signals for the device. For excellent detail on color management I recommend Color Management by Bruce Fraser, Chris Murphy, and Fred Bunting, a book I found to be deeply enlightening.

Practical color management starts in the operating system. Mac OS has provided OS-integrated color management since at least version 10.4 (Tiger), and possibly before. I don’t know if Mac OS natively supports on-screen proofing, or if that is application specific, as it is on Windows. Microsoft provides color management in Vista and XP, though at least the Vista version can be flaky, especially before SP1. The operating system level generally provides application of monitor, printer, and sometimes scanner calibration ICC profiles. The profiles are often generic, and therefore of dubious accuracy, but if you have calibration tools to get accurate monitor profiles, you have a chance of at least reasonably approximating the output. However, your application must support proofing mode, or at least this is true on Windows.

Color management is not a panacea—not all devices can represent all colors. Color management helps create pictures that look relatively good, or which have tolerable errors, but it does not mean WYSIWYG.

## Picasa

Picasa offers no color management tools. You can still gain more accurate rendering by using a good monitor profile, but it won’t reveal issues in your print process.

## Photoshop Elements

PSE7 offers no color management, either. Note though, that Adobe in general offers the best color management tools. In Adobe Lightroom and CSx you get tools like “show out-of-gamut pixels” which highlights areas in your image which will be altered during printing. I understand proofing modes are also supported.

## Paint Shop Pro

Surprisingly, perhaps, PSP offers color management for proofing. In addition to “basic color management” which merely accounts for your display, there are proof modes that combine your monitor’s calibration with a printer profile to provide a reasonable representation of what you’ll see on paper.

PSP is not perfect in this respect. As far as I can see there is no way to transform your image to carry the information for the printer—in other words PSP helps you see problems, but offers little that is specially designed to help solve them. There is no “out-of-gamut” tool to provide a quick snapshot of problem areas.

## GIMP

As of version 2.4, GIMP includes color management, with proofing modes and optionally out-of-gamut display. I tried this and it did not produce the same effects I got with PSP—that is, the picture looked fine in proof mode, and the only out-of-gamut areas were the subject’s pupils. In short, it did not work correctly. If it was my error then this may be the only affordable option to provide color management with near-Lightroom capability. Either way, prepare to invest significant time in mastering color management with GIMP.

# Image Combining

Enhancing dynamic range by combining bracketed images is not something I expect to use substantially. However, there are cases where such a feature would be useful. Image combining can require alignment first, so some utility for image registration is probably required too. Picasa, unsurprisingly, does not offer an image combining capability. PSP offers one, including an alignment module. PSE7 does not appear to provide image combining, though I would not be surprised if Lightroom does.

# Conclusion

My experience is that for sharing, basic editing, ordering prints, uploading, captioning, and tagging the free Picasa is unquestionably the best. For sophisticated editing Paint Shop Pro is a huge winner, with support for on-screen proofing, 16 bit per channel editing, bracketing combining, vector layers, and all of Photoshop Element’s editing capabilities except vibrance.

Maintaining monitor calibration is important, as is finding reasonable profiles for your printer or lab. However, the most important parts of color management are probably in getting the shot and in choosing the lab. If I weren’t so cheap I’d probably try Lightroom, which I believe has superior color management and presumably has more 16 bit per channel capability. However, I doubt its sharing utilities have much over Picasa.