Photoshop has been able to produce good panoramas for years with the Photomerge plug-in, and it’s a popular tool for some photographers who use Photoshop to build sweeping vistas from multiple shots. Other users find Photomerge very handy for combining images for use in QuickTime VR (QTVR) projects such as 360-degree online tours and other immersive interactive media.
I have always used Photoshop and a $49 program called CubicConverter to build QTVR: I combine images in Photoshop and then output the movie file with CubicConverter. However, Autodesk offers an application called Stitcher Unlimited 2009 that handles both functions extremely well. There are some pros and cons to using Stitcher versus Photomerge, but I like the fact that it’s a complete solution for VR professionals.
Create your panorama
In this tutorial we’ll learn how to import images into Stitcher, stitch them together in a panorama, fix any bad stitching or mismatched exposures, and export to QTVR. The five images in this tutorial are of St. Stephen’s Green in Dublin.
1. Import your images into Stitcher.
The easiest way to do this is to drag the image files onto the Stitcher interface, but there are also menu and icon commands that do the same thing. I recommend that you make the exposures consistent outside of Stitcher. During the import process Stitcher will detect the lens type and focal length, which you can accept or revise.
2. Use the Stitch Shots command to automatically begin the stitching.
Stitcher does a good job stitching shots together on the fly, every bit as good as Photoshop’s Photomerge feature. You’ll have greater success if your shots have a healthy amount of overlap: in my example, the first and last shots have very little overlap with the image next to them and Stitcher did not attempt to stitch them together.
Photos that are successfully stitched are marked with green in the Thumbnail View strip below the main window. Stitcher uses green, yellow and red to mark successful and problem images. The stitched images show up in their panoramic glory in the main window, and the three tools to move around are in the View menu—pan, zoom and roll. The menu bar doesn’t show it, but there are vital keyboard shortcuts for the Pan (Alt/Opt-drag) and Zoom (Cmd/Ctrl-drag) tools. These shortcuts make moving a lot easier and the menu commands are comparatively slow.
3. Manually stitch any missed images.
I dragged my two missing images from Thumbnail View to the main window. The left image stitches nicely just by dragging the image so it overlaps the image next to it. Stitcher fades the two images together to make a seamless transition, though in my case a man in the left image ended up losing some opacity due to blending with the second image’s background. Unfortunately, Stitcher does not have any retouching tools like Photoshop does, though you can stencil out part of an image and retouch it in Photoshop or another application.
The right image is a good candidate for Stitcher’s Manual Stitch command—images that overlap and have common landmarks do well with Manual Stitch. Select the right image and the one to be stitched to it and choose the Manual Stitch icon or menu item. An interface appears that allows you to pin common points on both images. In my example, the statue in the background and one of the railing posts were good common points. Once the pins are in place, click Stitch and Stitcher brings them together. Note that manually stitched images are marked with yellow while non-stitched images (like my left image) are marked with red.
4. Equalize images
There are two methods for equalizing images: use the Equalize All Images command or, if you have 32-bit High Dynamic Range (HDR) images, use the HDR exposure controls in the HDR menu. In my example, the fourth and fifth images have some overexposure compared to the three on the left. However, Equalize All Images doesn’t seem to work with unstitched or manually stitched images and it of course can’t fix incorrect colors like the sky in my fourth photo. The sensitivity of Equalize All Images is also buried in Stitcher’s preferences, making it a chore to tweak it for the best results.
Photomerge seems to do a better job of automatically equalizing images, though it doesn’t have the specialized HDR features that Stitcher offers. Photomerge produced a fully equalized panorama with the St. Stephen’s Green photos, and even figured out how to stitch the right image so I didn’t have to do it manually.
5. Render the final QTVR output
The real value of Stitcher is in the various formats it can produce: JPEG, QuickTime movies or QTVR, Pure Player Java or HTML and KML. The KML file is suitable for use with Google Earth. To publish a QTVR, select “Cylindrical QTVR” or “Spherical QTVR” from the Type menu and change the various settings as needed. The Render dialog box has four panels full of options for quality, output and scripting so it’s a complicated process but also very robust, and there’s a panel for saving and recalling settings so the process runs smoothly.
The coolest thing about Stitcher Unlimited 2009 is its range of features: there are several I did not write about, including hotspots, stencils, alignment and working with fisheye images and full spherical panoramas. I was impressed by the wide features that Stitcher offers to creators of panoramas and QTVR, and I think there is potential for more interactive images and multimedia with these tools.