Zoom zoom zoom - PhotoZoom Pro v2

by Thomas Theuerkorn, ©2007

Apparently there are still many paths leading to Rome, and while Genuine Fractals utilizes the most complex math, BenVista's PhotoZoom 2 takes a slightly different route. While not less complex under the hood, the goal is to keep the user from becoming a mathematician in order to use software that utilizes enhanced methods to go beyond the nearest neighbor limitations and even the popular bicubic interpolation.

From the BenVista website: "PhotoZoom Pro 2 is based on S-Spline XL: a renewed and improved version of our patented, self-adjusting, many times awarded S-Spline interpolation technology. As we did with S-Spline, our S-Spline XL technology again introduces a revolutionary breakthrough in digital image enlargement. It is able to render sharp and crisp clear image magnifications, perfectly focused, yet without the jagged edges, loss of detail or lack of photorealism that normally come with enlarging images."

[Interface] - The Interface shows the properties of the original picture with a navigator to allow quick access to specific detail, which is especially helpful in large pictures (output) where the essential 100% preview is restricted to a very small area of the picture and it’s easy to get lost. The new size of the output file can be defined through pixel size or print size or simply as a percentage of the original. A variation of print size is to keep the dimensions constant and adjust resolution to the respective output device. While these options are all fairly standard, the sliders to quickly select a size with the mouse are a convenient departure from convention.

However, it turns out to be rather difficult to move the sliders to a specific number. Oddly, even the pixel size seems to insist on two decimal places and setting to a meaningful value (like 300 dpi without decimal places) is virtually impossible without the help of the keyboard. The pictures shows an attempt to use the percentage slider to quickly set the output size to 670%. Not only does it require some dexterity but the 0.11 is certainly frustrating as there is no 0.00, the same applies to all the other settings where dpi even doesn't make sense other than a conversion artifact (from possibly internal metric units).

Beyond resizing a picture can be cropped directly as part of the process in PhotoZoom. This is advantageous to reduce the processed pixels to the ones you would actually need (which can be a true time saver depending on your file size and hardware). However, dragging the selection via mouse and observing corresponding size values in the status bar on the bottom left corner isn’t the most convenient way to achieve quick results and I personally would prefer to enter desired crop size via keyboard. The selection doesn’t become a crop until the respective button is pushed. Relatively unusual is the ability to flip the image vertically or horizontally or rotate in 90 degree increments, though the times this is needed may be relatively rare.

The stand-alone interface allows reducing used system resources since no host application like Photoshop needs to be loaded, and it’s the only path to batch processing in order to automatically process a bunch of pictures. The window’s appearance is largely the same between the plug-in and the stand-alone with only the eight icons on top and the menu missing for the plug-in. (The contextual batch list is of course not available in the plug-in version either.)

[Functions] - Despite it's single minded focus on the task of upsizing, PhotoZoom provides many ways to get there. While S-Spline and S-Spline XL are by far the most advanced methods there are still 9 other modes to increase or reduce a picture. For most users, these modes are of no significance as their output is similar to standard results achievable with most universal picture editors.

The output of S-Spline XL is somewhat unique and not directly comparable to competitive methods. The S-Spline and S-Spline XL algorithms are the main reasons to consider PhotoZoom Pro 2. While all methods allow some sort of fine tuning, S-Spline XL sports unsharp mask parameters and four parameters called Sharpness, Artificial Detail, Edge Boost, and Detail Boost. Most are self-explaining, but the Artificial Detail is a bit misleading since it really adds simulated film grain in order to reduce the smooth (painted) appearance that’s inherent to the S-Spline method. Adding grain in moderation can help reducing the artificial appearance of this algorithm. The Detail Boost on the other hand attempts to improve soft edges which otherwise might end up too blurred. Presets for every method allow to quickly obtaining results without studying the effect of each parameter. Factory installed are presets for typical applications including noise reduction and text improvements, but the user can also define and save custom settings.

PhotoZoom supports both Exif and IPTC data. Both are ways to embed data into a picture holding valuable information regarding author, copyright, date, technical information (like exposure, lens data, etc.). Most information is preserved though it isn't used anywhere in the process and cannot be edited either.

For a direct comparison to alternative scaling methods, please [follow this link].

[Performance] - Using the most advanced algorithm S-Spline XL as a reference, an 8.2 MPx picture for this test took about 20 minutes to be resized to 800% x 800% or 262 MPx. Content appears to have little impact on this number and the CPU graph shows that the algorithm leaves computing power unused. This is good for simultaneously working on other tasks (provided sufficient RAM is available) but also a common "problem" for a single threaded task like a single picture.

For comparison purposes, another 8.2 MPx was used to scale 500% in both directions (to 205 MPx). The heart beating in the test system is an AMD X2 4200+ with 2 GByte DDR400 (CL2) RAM, WD Raptor SATA hard drive, and dual boot Windows Vista/XP. With exception of Genuine Fractals 4 all tests were conducted under Windows Vista (32 bit). When comparing the numbers, it should be noted that "Genuine Fractals w/ sharpening" was the only instance exceeding the available 2 GByte of RAM and forcing paging. Photozoom Pro 2 used very little RAM in the process, but both advanced modes took significantly longer than any of the tested competition. Other methods in PhotoZoom were much faster, but wouldn't be a good enough reason to spend the money on this software either. It should also be noted that time is only half the equation and results between PhotoZoom and Genuine Fractals are hard to compare. Of course, the Bicubic Smoother in no match in achievable results either.

The CPU graph shows that even in batch mode, PhotoZoom “wastes” resources by utilizing only roughly 50% of the available computing power on a dual core processor. While this isn’t unusual for single picture processing, it’s a mild surprise in the batch mode where PhotoZoom’s use of available resources would easily allow for two pictures to be processed at the same time. This test relies on AMD’s Athlon X2 4200+ dual core with 2 GByte of DDR400 memory. Faster processors should directly translate into reduction of processing time as the process remains completely in the memory and doesn't suffer restrictions imposed by frequently moving data to and from the hard drive. (At least when considering 2 GByte of RAM). On the positive side, running a batch process on a dual core leaves enough resources to continue working or browsing the net.

[Batching] - PhotoZoom Pro 2 appears to be strictly single threaded in a sense that despite available CPU resources, only one picture is being processed at a time. The time saving can still be significant by simply allowing the computer to process multiple pictures unattended. The process is easy enough, simply add pictures to the list that opens when choosing the "New Batch" icon and that can even be the same file multiple times to process for different purposes. Changes are as easy as selecting the picture in the batch and modify any settings as usual in the main window. No macro language or in-depth knowledge of creating scripts is required.

[Overall] - PhotoZoom Pro 2 is a fantastic application for a niche purpose. With the $150 sticker price its not really cheap, but within the market range and certainly a lot cheaper than upgrading equipment. With large scale printing being the main application, electronic publishing is hardly gaining much from PhotoZoom et al since the needed pixels for any monitor display are typically less than 2 MPx or a fraction of any digital camera in today's market. Within its purpose. PhotoZoom Pro provides the ability to maintain edge detail of well defined features with even extreme scaling ratios. Less defined features gain little or no advantage, as information cannot be invented that's not in the original in one way or the other. The standard output of both S-Spline methods can appear a bit plastic and artificial, but most of that can be minimized with the included fine tuning. That's not to say that the standard look doesn't have it's purpose and the slightly painted style can help improving picture styles where fidelity isn't the main focus.

Stand-alone interface and good functionality are main arguments for PhotoZoom Pro 2, and the support for both Photoshop as well as compatible host applications (like Corel's PhotoPaint) makes this program more versatile than competitor Genuine Fractals which requires the pricey Photoshop and ultimately needs more resources as well. Further, PhotoZoom offers more flexibility by providing multiple scaling methods as well es extensive fine-tuning which allows tweaking of the result more than any other scaling program (that I know).

Links

• BenVista PhotoZoom Pro v2 product page
• Genuine Fractals 5 review (with comparison view)
• DxO Optics Pro v4 - Standard review
• Adobe Photoshop Lightroom v1.0 review
• Lightcrafts Lightzone 3 review
• RAW converter comparison

Disclaimer: Thanks to Hugo Eijkelhof of BenVista Inc. for providing PhotoZoom Pro 2 for this review. The author is not affiliated with or compensated by BenVista Inc. or it's associates. Opinions voiced in this review are solely those of the author.

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