virtual tour example

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Step A -- Stitch the first row

All photos used in this tutorial are 2006 Stephen Wateridge, used with permission

In this step, you stitch the first row of images into a horizontal panorama.  This first row is used as the starting point for the full panorama.  It establishes the focal length and the horizontal axis of the panorama.  I recommend you start with the row that is closest to having tilt angle zero because it is the reference for all other rows.

Thanks to Stephen Wateridge for giving permission to use his photos in this tutorial.  His hand held panoramic photo of the central dome of the Reichstag lends itself well to this technique.  The hand held method with vertical lines cannot be used because there are few truly vertical lines in this scene. (The "vertical" lines between the panes of glass are curved inward.).  However, there is a horizontal line that is approximately at eye level that can be used as a substitute for the horizon line.  Therefore this stitching procedure is the one that should be used for photos like these.

  1. Start a new project and immediately Cancel the Wizard.

  2. Use the Import images... command (File menu) to import the images for all rows into the project file and make sure they are arranged left to right in each row, one row after the other.  Here are the images we'll be using in this example:

  3. Select the thumbnails in the first row (I recommend you start with the row closest to tilt angle zero) and choose the Stitch with the Wizard command (New image menu).

  4. Choose Manual photo stitching on Wizard 2/9.

  5. Select Automatically detect focal length and Correct barrel distortion on Wizard 3/9.

  6. I recommend not selecting any checkboxes on Wizard 4/9.

    • You should disable automatic fine tuning of the image alignment because stitching is a lengthy process and may require some back-and-forth in the program. Fine tuning in the Wizard will slow things down. You can apply the Fine tune command (Image menu) after stitching is finished, so its often best to postpone this step until everything else is just right.

    • If you have used your camera in manual exposure mode, exposure matching and exposure correction should be unnecessary.  If you decide later you want to try these options after you're done stitching, you can use the Blending properties dialog box (Tools menu) to change the settings.

    • Sharpening is best applied to the final image, not to each stitched row individually. so we disable it for the individual rows.

  7. Select Partial panorama and Spherical projection on Wizard 5/9.

  8. Place stitching points on Wizard 6/9 to stitch the first row of the panorama.  I recommend this procedure for placing stitching points:

    • Place stitching points on one image pair. I recommend using distant points and/or points all in the same plane.

    • After placing 5 points, you should get a dot in the Images list.

    • Once you have the image dot, go back to each stitching point in turn and examine them at large zoom scale (400% or 500%).  Adjust the stitching points so that they match well on the two images.

    • Repeat this procedure for all image pairs.  It's important to get a dot in the images list for each pair of images.

  9. Advance to Wizard 7/9.  In this step, you'll use the warping grid to correct the manual stitch to be level and square.  For more information about the warping grid, refer to the section "Wizard step 7/9 Preview at low resolution" in Chapter 1 of the online help.

    When you first enter this Wizard step, it will show you the results of the manual stitch before applying the warping grid.  In our example, the image is rotated slightly counter-clockwise from level.

  10. Choose a horizontal line that is visible in both rows and is approximately at eye level.  This will give the warped image the most natural perspective.  For landscapes, the horizon line is a convenient choice.  You'll use this horizontal line as a reference for warping the two rows to be level and consistent with each other.

    In our example, we select one of the horizontal lines between sections of window glass.  Use the "horizon method" as described in the section "Wizard step 7/9 Preview at low resolution" in Chapter 1 of the online help to place three handles (red dots) on the horizontal line.

    I recommend choosing three easily recognized points that are visible in both rows of your image.  Using the same three points for both rows will guarantee that the two rows are warped consistently.  Refer to Detailed view of handle placement to see exactly where the handles are placed in this example.

    After placing the three handles, click Apply warp.

  11. Examine the preview image.  After applying the warp, the horizontal line you chose should be perfectly straight and level.   If not, adjust the warping grid until you are satisfied. There is no loss of image quality if you apply the warping grid multiple times because the image is recomputed from the original image data each time you rewarp.

  12. Advance to Wizard 8/9 and select Prepare for internet display and Maximum size.

  13. Advance to Wizard 9/9 to complete the stitch and click Done to exit the Wizard.

  14. At this point, you should see a stitched and cropped thumbnail in the upper pane and the cropped image in the lower pane.

  15. Choose the Properties command (Image menu).  Write down the W value from Image size (pixels) in the Image properties dialog box.  We'll need this value in a later step.  We'll refer to it as StepA_W.  In our example, this value is 2359.  Click Cancel to close the Image properties dialog box.

  16. Choose the Panoramic properties command (Image menu).  Write down the HFOV value from Horizontal field of view (degrees) in the Panoramic image properties dialog box.  We'll need this value in a later step.  In our example, this value is 103.298.  We'll refer to it as StepA_HFOV.

  17. FOR THE BOTTOM ROW ONLY:  If you are starting with the bottom row, also write down the Below value from Vertical field of view (degrees) in the Panoramic image properties dialog box.  We'll need this value in a later step.  In our example, this value is 16.2123.  We'll refer to it as StepAB_Below.

  18. Click Cancel to close the Panoramic image properties dialog box.

Advance to Step B -- Stitch the remaining rows

Up to The list of the major steps

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Revised: January 13, 2007

Text  2007 Smoky City Design, LLC and John Strait
Photos 2006 Stephen Wateridge, used with permission