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Mac OS X Zip Expanding Utility

Firefox (and possibly other applications) may ask you what you want to do with .zip archives that you download from the Internet. If you want to expand them with Mac OS X (rather than StuffIt Expander), you may be unsure of which application actually does the job. You're looking for Archive Utility (in Leopard and later) or BOMArchiveHelper (in Tiger). In either case, the application is stored in Hard Drive/System/Library/Core Services/. Don't move it from there, though, or you'll confuse matters.

 

 

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Camels and Horses: Alternatives to Photoshop

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Adobe Photoshop reminds me of a camel: a horse designed by a committee. It is ungainly and awkward to control. It is remarkably useful - no other photo editor will do so much - but it is not an easy beast to ride.

I personally find Photoshop indispensable, not so much because of what it can do itself as because it is necessary to run some plug-ins by Asiva, particularly Shift+Gain. Unfortunately, Asiva have shut up shop. Their plug-ins work well with today's versions of Photoshop but will not be recompiled for Intel-based Macs. For this reason, I have been keeping my eye out for a horse. I have not yet found one that I want to buy - Shift+Gain is difficult to replace - but I have found a couple that look interesting.

I have also found a cheaper camel, PhotoLine. This is the poor man's Photoshop CS2. It is comparable to Photoshop CS2 in its powers to create and confuse, but it is priced like Adobe Photoshop Elements. It is not quite so fast and stable as CS2, but its speed and stability appear to be respectable. Unfortunately, its documentation is so meagre that for many people, its advanced functions are likely to be inaccessible.


Photo Editor Requirements -- Before I talk any more about specific products, it would be sensible to describe my expectations of a photo editor. Here, in no particular order, is a list of what I want one to do.

CORRECT OPTICAL PROBLEMS

  • Remove colour fringing. Some colour fringing is caused by lenses' magnifying different wavelengths different amounts - chromatic aberration. This kind of fringing can be removed with a chromatic aberration control that enlarges colours differentially. Unfortunately, most of the colour fringing I encounter has other causes and is too irregular to remove this way. I usually need to convert the fringes to grey.
  • Sharpen either the entire picture or selected parts of it. There are many ways to sharpen a picture. The usual method exaggerates the contrast at edges, but it is often preferable to sharpen the image optically. To sharpen edges the computer first determines what is an edge - it usually does this by looking for differences, pixel by pixel, between the original image and a slightly blurred copy, an "unsharp mask" - and then alongside each edge it darkens dark pixels and lightens light ones. To sharpen optically is to reverse blur. Blur is the spread of a point of light into a disc. A computer can partially reverse this by transferring to each pixel some of the response of every pixel surrounding it.
  • Correct the barrel or pincushion distortion that is inevitable with zoom lenses. Sometimes I also use this facility to compensate for my having the wrong lens on the camera, to create a conventional perspective from a fish-eye lens.
  • Squeeze a picture anamorphically - more at the edges - to correct the distorted magnification that a wide-angle lens creates toward the edges of the frame.
  • Correct vignetting.
  • Blur selected areas to create the effect of selective focus.

CORRECT PROBLEMS WITH HOW THE CAMERA WAS HELD

  • Make converging lines parallel.
  • Rotate the photo so that vertical lines are plumb.
  • Remove the blur caused by a moving camera. To do this requires optical sharpening in a single direction.

TONAL ADJUSTMENTS

  • Adjust the overall distribution of tones from dark to light.
  • Enhance or reduce the contrast of adjacent tones, both throughout the picture and in selected areas. I often want to control not just the contrast of brightness but also the contrast of hue and saturation. (See "Reality and Digital Pictures," 12-Dec-05.)
  • Enhance the contrast of fine detail.
  • Remove colour casts differentially according to their location, to compensate for different sources of light in different parts of the picture, and according to their brightness, to compensate for the blue shadows of a sunny day.

CHANGES TO THE SUBJECT

  • Remove blemishes.
  • Replace one colour with another (e.g., change the red reflection in red-eye to white, change a necktie from yellow to dark blue).
  • Remove/add motion blur from/to selected parts of the photo, either to sharpen something that was moving or to create the appearance of movement.
  • Replace parts of a photo (e.g., insert a more attractive sky).
  • Add an image of the sun with naturalistic flare. If you take a picture with the sun in it, the flare and reflections it causes are uncontrollable. When possible I prefer to frame the picture with the sun just out of view or with something in front of it, then add it in the computer.

MECHANICAL NECESSITIES

  • Remove digital noise.
  • Remove dust.
  • Enlarge the image by interpolating pixels, or shrink it.
  • Crop the image.
  • Edit the IPTC data fields attached to images.
  • Handle 16-bit colour.
  • Display colour using ICC colour profiles.
  • Read and write files in TIFF, PNG, and JPEG formats. (I have given up on JPEG 2000. Although it is preferable to JPEG, it has not become adopted widely enough to be useful.)


Photoshop and Friends -- By various sets of hooks and crooks, Photoshop CS2 can do all of these things. Photoshop Elements 5 cannot squeeze pictures anamorphically but it can do everything else, although it's currently available only for Windows. Photoshop Elements 3 and 4 are also unable to handle optical sharpening and removal of motion blur. In general, Photoshop CS2 offers greater control and complexity than Photoshop Elements, but for some complex jobs it is simpler. However, some of these tasks can be done even better and/or more easily using third-party products. I routinely supplement Photoshop CS2 with Photomatix to control contrast (see "Photomatix: A Virtual Magic Wand," 16-Oct-06), Noise Ninja to reduce noise and enhance fine detail, Asiva Shift+Gain to manipulate colours and remove fringing, and PhotoZoom Pro to make enlargements. (For more details on these last two products, see "Editing Photographs for the Perfectionist," 27-Sep-04.)


PhotoRetouch -- PhotoRetouch Digicam is the hobbled, amateur version of PhotoRetouch Pro. I was unable to try the Pro version, so my comments are inferences and not based on direct experience.

Both applications are designed specifically and exclusively for editing photos. Compared to Photoshop, they offer a limited set of manipulations - they will not do for laying out an ad or brochure - but for editing photos, the manipulations available seem well thought out. To apply a manipulation, you either paint it on with an air-brush tool or apply it to the whole image and then erase it where you do not want it. You never get involved with selecting, layering and masking. This makes PhotoRetouch less flexible than Photoshop but more efficient and straightforward.

On my list of requisites, PhotoRetouch can do everything with reasonable ease and competence except squeeze frames anamorphically, straighten curved lines, enhance the contrast of fine detail, remove or create motion blur, replace parts of an image, add a sun, and handle PNG files. It does not seem to do optical sharpening, but it provides a "smart sharpening" algorithm that is more sophisticated than a simple unsharp mask. The Digicam version is restricted to 8-bit colour.

I suspect that the Digicam version will fill the needs of almost anyone who does not use an SLR - i.e., anyone who uses a camera with an 8-bit image sensor. The Pro version will handle most advanced amateurs' and professionals' needs as well, and do so more handily than Photoshop, but any pro is likely to find Photoshop necessary some of the time, and I myself would supplement PhotoRetouch, as I do Photoshop, with Photomatix, Noise Ninja and PhotoZoom Pro.

Although PhotoRetouch has fewer controls than Photoshop, the controls' labels can be comparably confusing. For example, "color change" is deemed different from "color modify" and "quantifier" removes colour casts. Also, although PhotoRetouch is simpler than Photoshop, it still requires a significant investment of time to learn, and the Digicam version includes no help files or manual, just a pointer to some QuickTime tutorials on the Web. I downloaded the Pro version's manual and ignored the parts that are obviously inapplicable.

The Digicam version generally worked well for me, but I did find a built-in booby trap worth noting. Saving a 16-bit image overwrites it as 8 bits without any warning.

Binuscan sell the Digicam version over the Web with pricing and terms that are neither obvious nor straightforward. The PhotoRetouch Digicam Web page states that the program is free and has a Buy button that opens another page saying it costs 49 euros (~$60-$65), but that it can be purchased only from within the application. If you download the application thinking it to be free, after you try to save a file, a window pops up to inform you that you are using a demo limited to 30 saves. That window displays a Buy button. Clicking the button brings up a Web page stating prominently that the product costs 49 euros today but will cost 149 euros (~$180-$190) once 3,000 copies are sold. The clear implication is "soon." In addition, fine print at the bottom of the page says, "We recommend reading our General Sales Conditions before confirming your order.... Downloaded software cannot be returned." If you click on the link to those conditions, and if you bother to read what appears to be a typical license agreement and to decipher the legalese, then you learn that the agreement is not a normal one. You are purchasing the right to use the product on one computer only - not any one computer but the one you installed it on initially. An activation scheme prevents it from being moved. If your computer is stolen or breaks and needs to be replaced, then if you document this, Binuscan will permit you to activate it on another machine, but only once and only within the first year. Thus, Binuscan expect you to pay 49 euros now plus an additional 149 euros the next time you upgrade your computer.

Binuscan are even more opaque selling the Pro version. They do not advertise any price for it anywhere on their site. Neither do they reveal the terms of the license they are selling nor mention a guarantee. I queried them about price and licensing, but they did not answer. I then had some friends query them as putative customers. Binuscan quoted $950 plus $30 to $40 shipping. In answer to a specific question, they told one of them that the Pro version can be installed on any number of computers but requires a USB key to work. They did not answer his query about a guarantee, nor did Binuscan supply the copy of the license agreement that the other fellow asked for.

Considering these products on their own, I would recommend them highly, but the business practices of their developer give me pause. Also, I should note that the Digicam version holds a trap for the unwary. Learning to use a photo editor efficiently and effectively takes so much time that few people will willingly switch from one to another. In practice, people do not buy a photo editor, they purchase a license and then they marry the developer and support his future issue. If you own a point-and-shoot or "prosumer" camera, PhotoRetouch Digicam may be perfect for you now, but if you ever buy an SLR, then at least some of the time you will want to be able to work with 16-bit colour. To do this you will need the Pro version. If you have learned PhotoRetouch well, then you will have the choice of losing your investment in time - few of your skills will transfer to Photoshop - or shelling out a thousand dollars to upgrade.


LightZone -- LightZone is a new horse in the race, a yearling with real promise. It is somewhat unusual under the hood and has a unique user interface, an interface that is simultaneously simple and sophisticated. LightZone permits novices to do things that require advanced techniques in Photoshop.

Instead of painting pixels like Photoshop and PhotoRetouch, LightZone manipulates images by piling up layers of calculations - in computer jargon, by stacking vectors. You pull tools down into a windowpane and see their manipulations applied to the image. You can apply a tool to a limited area by drawing a region with a spline tool or bezier tool or polygon tool, and you can feather the edge of the region with the drawing tool. If you dislike the effect of a tool, you can change or reorder the tools.

Of course other photo editors stack vectors too - Aperture and Imaginator, for instance. The differences between LightZone and other products lie in a dearth of confusing gimmickry and a set of unusually versatile tools. For example, LightZone's noise tool doesn't just remove granular noise, it can remove thin colour fringing as well.

Working with LightZone is radically different from working with Photoshop. Instead of deciding which of many tools to apply once, you decide how to apply a few tools several times in different ways. For example, to control contrast Photoshop offers seven dialog boxes accessible directly from menus, plus, for advanced users, contrast masking. In lieu of these LightZone offers only a ZoneMapper and a ToneMapper. The former is a more intuitive equivalent of Photoshop's Curves tool; the latter is unique. Imagine your photo is hammered in relief on a sheet of copper. You want to modify the depths of the relief to make it clearer. To do this you (1) choose the size of your hammer, (2) control the strength of your blows, (3) decide whether to spread your blows over broad areas or aim them at spots where the contours change, and (4) decide whether to adjust all parts of the relief similarly or to adjust them differentially, in proportion to their depth. That's how Lightzone's ToneMapper controls contrast. Sliders control the first three parameters and a pop-up menu controls the fourth. You can hammer the entire picture with it, or any portion of the picture, as many times in as many ways as you like. (The hammer is a combination of two esoteric manipulations applied to luminance: the application of a contrast mask plus the application of a mask defined by an arcane, non-linear mathematical device called a bilateral filter.)

LightZone will do some remarkably complex manipulations with a small number of simple tools but it is also missing a few basic capabilities. Two lacunae are particularly limiting: LightZone will not correct converging lines and it provides no way to deal with colours selectively - to brighten only yellows, for example, or to desaturate red fringing that is too broad for the noise tool to remove. The developers are planning to add those features soon. When they do, you can expect a lengthy review. This is a product worth watching.

Although LightZone looks as though it uses Core Image, it is actually programmed in Java. This means that it runs under Windows and Linux as well as Mac OS X. Version 1 costs $150 and includes a free update to version 2, which purportedly will cost $250. A demo of version 1 is free for the downloading, as are a public beta of version 2 and the complete package for Linux.

    PayBITS: If Charles's recommendations for Photoshop alternatives
    were helpful, he asks that you make a donation to Doctors Without
    Borders: http://www.doctorswithoutborders-usa.org/ donate/
    Read more about PayBITS: http://www.tidbits.com/ paybits/

 

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