This update to the RealViz panorama tool brings new workflow and image-editing enhancements to what was already a slick, efficient application.
Stitcher works by assembling rows of multiple overlapping images together to create panoramas, 360-degree movies or walkthrough VR scenes complete with ‘hotspot’ links to Web sites and other forms of media. The images are assembled from the Image Strip storage area onto the inside of a virtual sphere, as if papering the walls.
The size and angle of the sphere in the main Stitching Window are dependant on the camera’s focal length, which Stitcher calibrates along with distortion parameters from the original images. No information is required about the camera or the scale of the scene, but for the shots in this review, we enabled Stitcher’s Read Focal from EXIF data function to initialize the focal-length value for each new project. This was based directly on EXIF information imprinted by a Canon Digital Ixus 430 and PowerShot S45.
Dragging images over each other results in a ghosting effect that helps when aligning the elements of the image together. The images’ opacity can be adjusted in the reorganized Preferences – a welcome workflow enhancement. You need at least three rows of shots covering the full 180 degrees for a 360-degree VR panorama.
Taking the original photos is thus a key part of the Stitcher process, and they should be shot with stitching in mind; the manual has helpful hints about positioning and shooting angles. There are, of course, special tripod heads for shooting panoramas, but you can get by with a steady hand and a bit of patience for most jobs.
Positioning the second and third tiers can be tricky: to align objects, you need to nudge and rotate them into place. You can use a keyboard shortcut for this, which displays a yellow pivot point on the selected frame. It’s still easy to get wrong, however – especially if the image display resolution isn’t all it could be. Stitcher can adjust this, though, using more new Preferences tabs. The maximum texture size, which sets the image-definition display quality, is 1,024, with the default value pegged at 512. A G4 with a decent amount of RAM and fast graphics card will have no trouble with this side of things.
The problem with taking multiple images, especially outdoors, is that the light changes over the duration of the shoot. To counter this, Stitcher has an equalize function.
Another problem is that artefacts can creep in to the scene, especially where images overlap and something has changed from one moment to the next. This version addresses this in a number of ways. There’s an enhanced Stencil tool, which is great for fixing human movement. The Stencil tool can also crop images to delete undesirable areas and can reduce the optical vignette effect or darkened edges, on an image taken with a wide-angle lens
Another enhancement is the ability to edit an image in an application such as Adobe Photoshop before rendering. You can set this in Preferences, then Control-click on an image in the Stitching Window or the Image Strip to open, edit and save the image.
Rendering options have also been improved, offering a wide choice of interpolation algorithms. You can choose from Nearest, Bilinear, Bicubic, Mitchell, Lanczos3, Lanczos4 and Lanczos5. As a guide, Nearest gives the fastest render time but the poorest-quality image, and Lanczos5 gives the slowest render time but the highest-quality image.
You can also choose to maximize the render resolution without degrading the result by selecting the Best Rendering Size function for a 1:1 render. The size of the render is calculated according to the image size and the size of the Stitching Window. Another new feature lets you render a panorama using the render parameters from a previously saved project, thus dramatically speeding up any batch processing.
Panoramas can be rendered as a cube, plane, cylinder, sphere projection, as VRML and as a cubical projection for use in Director as a Shockwave asset or a cast member. Stitcher can export also in QuickTime VR form (Cylindrical QTVR and Cubic QTVR). A preview option is new in the QuickTime Movie Settings tab of the Render options window. This lets you set default parameters for the QTVR render interactively, by dragging in a preview window.
When Stitcher renders a panorama, the alignment is based on drawing horizontal or vertical lines on frames visible in the Stitching Window. A new tool, Auto-Align Panorama, can do this automatically, although this is best used on a single row of three or four images.
Stitcher has also enhanced its Photoshop export tool, which now has the ability to fully edit rendered panoramas in the image editor. The PSD file produced from the planar panorama option comes complete with all frames that make up the projection as layers. You can then go into individual layers and mask off and correct any artefacts that have produced ‘ghosts’ in the panorama by manipulating the opacity of the image masks.
Stitcher 4.0 further refines an already effective application. It’s pricier than its competitors, but if you’re serious about panoramas for Web design, 3D modelling or artistic ends, this is the package to use.