Stitcher

Rating:
Updated: 1 Jul 2008 at 20:49 GMT, by James Rigg [Panoguide]

This review refers to Stitcher Express 2 / Stitcher Unlimited 5.7

Since Autodesk acquired RealViz in early May 2008, the Stitcher product line has been simplified to just Stitcher Express and Stitcher Unlimited (Stitcher Pro and Stitcher Unlimited DS have been dropped). The RealViz website includes a convenient Stitcher comparison table

The two versions of Stitcher aim to cater for everyone from the amateur to professional virtual tour creator and also providing solutions for both low and high budgets. The underlying stitching engine and core features are the same in both versions, which is why I am reviewing them together here. In this review I will highlight differences between the versions where appropriate.

What's new?

There are a few small changes in 5.7, the most noticeable of which is the simplification of the product range (mentioned above) and updated low prices. The two-fisheye-shot stitching in Unlimited DS is now in Unlimited. The user interface is improved with GPU acceleration, 2D as well as 3D preview and selectable rendering.

Stitcher Unlimited 5.6 introduced Mac Universal compatibility and support for High Dynamic Range (HDR) imaging - see below for more details.

Overview

Stitcher was probably the first really user-friendly spherical stitching software, and I was really impressed with it when I first reviewed it on panoguide. At the time (2001) the alternatives were Helmut Dersch's PanoTools (using the optimizer, so having to write a script in pseudo-code), Enroute's Powerstitch (since discontinued), and iMove's Spherical Photo Solution. Of these Stitcher was, in my opinion, by far the easiest to use.

Work the way you want to

Some stitching software provides fully automatic alignment and stitching, without manual control if the software gets it wrong. A few products provide manual control, without much automatic functionality. Of course what you really want is the best of both worlds and that is precisely what REALVIZ Stitcher gives you.

Stitcher provides fully automatic alignment and you don't even have to put your images in any kind of order. You can align them one by one by dragging them into alignment and Stitcher will fine tune the position for you (or you can force a stitch regardless). And for more manual precision, you can set control points (matching points between any pair of images) which Stitcher will then use for alignment. You can also use any combination of these ways of aligning images.

If your pictures contain plenty of detail, Stitcher should be able to automatically work out the alignment of the images for you. But if you shoot an outdoor scene with lots of featureless blue sky, automatic stitching might not be able to work out how to accurately position sky shots. Now you can let Stitcher automatically align everything, and then adjust the sky shots yourself afterwards - really simple.

Fisheye lenses and linear distortion

Stitcher will automatically recognise your lens from the EXIF data in your images, or you can specify the lens yourself. The best bit is that Stitcher can also calculate linear distortion in your images and compensate for it. Just stitch three images and then select High Distortion to calibrate your lens. Providing the three images you are using contain plenty of detail, Stitcher will accurately calculate your lens's linear distortion characteristics and compensate for them.

Stitcher Unlimited includes fisheye lens support for stitching 2 or more fisheye images, and this includes 2-shot circular fisheye lens stitching (just like iPIX used to do). This also includes support for barrel fisheye images. "Barrel" means that you used a super-wide 8mm equivalent fisheye lens which is supposed to create circular 180+ degree field-of-view images, but you did not use a full-frame digital SLR. The effect is that the sides of the image get cropped, so your images have curved top and bottom and straight sides (barrel shaped).

Stencils and blending

Moving people, vehicles and other objects can cause real problems when you shoot panoramas - you can easily end up with ghosts, vehicles cut in half and so on. If you use any software other than Stitcher, you probably have to retouch your images afterwards. Or maybe you output layered PhotoShop PSD files and you adjust the blending.

In Stitcher resolving these problems is really easy. If someone moves between shots, open the stencil tool and draw a polygon around the person and select Preserve Inside. In another picture, a bus is half way out of shot and you want to make sure you don't end up with half a bus in the stitch - draw a polygon around it, and this time select Remove Inside. It's really quick and easy and a lot faster and easier than retouching a layered PhotoShop file. If nothing else about Stitcher impresses you, the Stencil functionality should.

Many output options

Both versions of Stitcher can create flat, cylindrical and spherical panoramic images in JPEG and TIFF formats. QuickTime (cylindrical and cubic) as well as HTML publishing is also supported by all of them. QuickTime VR is particularly well supported in Stitcher and I think every possible option and QuickTime feature is made available and easy to use.

Stitcher Unlimited adds support for 16 bit images and allow you finer control of the rendering process. You can control the blending method and that includes using Enblend if you want to. You can also control the sharpening, interpolation method and save all your render settings for easy reuse. Stitcher Pro and Unlimited also provide a few more input and output formats including PhotoShop PSD files with or without layers and masks. Note that includes layered PSD as source files for stitching.

Stitcher Unlimited also supports cubic image output (i.e. output the 6 sides of a cube as separate images), Shockwave 3D, VRML, ImmerVision PurePlayer and it allows you to create hotspots in your QuickTime movies. Stitcher Unlimited can also convert between panoramic image projections, and convert previously saved images into QuickTime VR movies, etc. For example, you can output your spherical panorama and edit it in, say, Adobe PhotoShop, and then convert the edited image to a QuickTime cubic movie easily afterwards. (You can of course do this with any stitched image, cylindrical, cubic etc, and you can convert the edited image to any of the other formats supported by Stitcher.)

QuickTime support

The QuickTime support includes just about everything you could want - you can control codecs, preview options, streaming, set the playback window size and set the default, minimum and maximum zoom, pan, tilt etc. This means that when exporting an image that is less than a full spherical image you can create a cubic movie and then limit the user's ability to 'move' in the panorama so as to avoid displaying the black 'blank' area. (It also means that if you export a cylindrical panorama of less than 360 degrees you can limit the left/right pan.)

Stitcher Unlimited provides a really easy-to-use hotspot interface for creating QuickTime VR virtual tours for the web. At the time of writing this review, Stitcher is the only software solution I know of for Windows that offers QuickTime cubic hotspot authoring.

Templates and batch scripting

If you shoot a lot of panoramas you've probably got your prefered equipment and way of shooting your pictures. Stitcher Unlimited allows you to save a project as a template and use it to stitch different sets of images that were shot in the same way. Unlimited also features an additional render button the "Batch Queue". You can select multiple projects to render and then kick them off and go out and do something else while yout computer does the hard work.

Who needs a leveller?

If you are shooting a spherical panorama, you really don't need to make sure your camera/tripod is level any more. Not only can Stitcher guess where the horizon is in your project and level the scene, you can also quickly and easily define the precise horizon by drawing vertices that are horizontal or vertical (for example the side of a building).

The real time preview of the panoramic image makes it easy for you to adjust the viewpoint (important if you want to print or perhaps retouch the panorama afterwards). Stitcher Unlimited allows you to change the real time preview projection (cylindrical, spherical, cubic etc).

Movie output

Stitcher can also output a movie from your panoramic image. Just enter movie editing mode, and you can define a sequence of movements around the panoramic scene and output them as a QuickTime or AVI movie. You can control frame rate and resolution too. I have not tested it, but I suspect that DVD output (just a movie, not interactive of course) should be really easy.

HDR in Stitcher Unlimited

The core engine of Stitcher processes images in 32bits (a JPEG image is 8bit, a TIFF image up to 16), and includes support for High Dynamic Range (HDR) stitching using the OpenEXR (EXR) and Radiance RGBE (HDR) file formats. The main target audience for this functionality will be computer game and film special effects creators who need HDR Images to achieve convincing special effects. However this feature should also interest professional photographers having to deal with difficult (e.g. high contrast) lighting conditions.

To create an HDR panorama using Stitcher Unlimited, you will need to shoot multiple exposures for each frame that makes up the panorama. Next combine the multiple exposures for each frame in an EXR or HDR image file using PhotoShop CS, Photomatix Pro or similar software. You can then load your EXR or HDR images into Stitcher and stitch the panorama just as you would if you were using non HDR JPEG or TIFF files.

5.6 was the first version of Stitcher to support HDR and I anticipate future versions will improve the functionality. The stencil functionality of Stitcher, which is so powerful and useful for non HDR panoramas, is less useful for HDR images, because you cannot apply a stencil selectively to one of the multiple exposures you have shot. Shooting an HDR panorama in public may therefore be more complicated because stencils will not help you quite as much as they do in a non-HDR panorama. I have yet to properly test and explore the HDR functionality myself, so please let me know if you know better!

A product company that listens

Several previous versions of Stitcher have been reviewed on panoguide. Each and every time a new version comes out, criticisms made on panoguide of the previous versions get fixed. And the latest Stitcher products are no exception. As if to prove the point, here are the criticisms of version 4.0 and what has happened since:

1. If you have to manually align images, it is not easy. With control point stitching you can now easily and precisely stitch images manually, in addition to the drag-and-drop interface.

2. Fisheye lenses not supported. Stitcher Unlimited now supports fisheye lenses.

3. Too expensive compared to alternatives. There are now several versions of the Stitcher product now to cater for a wide range of budgets. (See Conclusions below).

So as you can see the RealViz team listen. And so far I have not found anything I dislike about the latest version of Stitcher.

Market position & conclusions

AutoDesk, which incorporates RealViz, specialises in software imaging solutions for imaging professionals from film special effects to 3D CAD models and animations. So, as you might expect, Stitcher is designed specifically to create high resolution spherical/cubic panoramic images from any number of images. Part of the reason for multiple versions of Stitcher is to better compete with the full range of products from competitors, from cheaper image-stitching-only products (PanaVue Image Assembler, PTGui) to full-suite solutions (such as iPIX Interactive Studio).

PTGui provides similar stitching flexibility to Stitcher Unlimited (fully automatic alignment, control points, drag-and-drop, etc) and has very similar rendering precision and functionality. Although PTGui is cheaper than Stitcher, Stitcher provides some very valuable additional features in particular QuickTime VR support and stencils. Easypano Panoweaver is another well-known fisheye lens image stitching solution, and interestingly at a similar price point to Stitcher Unlimited. The differentiators are: QuickTime VR output (including hotspots), the stencil functionality and multi-row stitching in Stitcher Unlimited.

If you want to stitch fisheye lens images and you are on a tight budget, you will still probably want to go for PTGui or another PanoTools-based product. But if you are looking for an all-in-one solution to your image stitching needs, I think it's pretty hard to beat Stitcher Unlimited.

Once you try Stitcher and explore all of its features and capabilities, you won't want to use anything else.

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Rating:
Updated: 20 Sep 2007 at 15:57 GMT, by Psychedelicious

Stitcher is very nice... and in many cases will provide flawless output with a minimum of fuss. I'd love to give it 6 stars, but I cannot because PTGui deserves 6 stars, so Stitcher can only have five. Why is this? Stitcher is too expensive, and is also not quite capable of reaching the level of perfection that PTGui can. PTGui is capable of perfect stitching, so long as one uses a very well calibrated pano head, and a prime lens. Stitcher is still prone to slight errors even when calibration is perfect. Stitcher is great for web tours, the slight errors are too small to see a web resolution... but for prints, PTGui can produce superior results thanks to superior control, more blending and output options, and better interpolation.

The catch is this... PTGui can be more complex to use, especially if you want to push it to the limit. Stitcher and PTGui produce similar results in their default modes, so Stitcher's ease of use may be the deciding factor for those who prize simplicity over precision.

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