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Step B -- Stitch the remaining rows

In this step, you stitch the remaining rows of images into horizontal panoramas that are parallel to the first row.  If all goes well, these rows will match the spherical coordinate system of the first row.  Repeat these steps for all of the rows.

  1. Choose the Show imported images command (View menu) to display the imported thumbnails in the lower pane.

  2. Select the thumbnails for the row and choose the Stitch with the Wizard command (New image menu).

  3. This time, remove the checkmark from Automatically detect focal length and then choose I am certain of the focal length on Wizard 3/9. This guarantees all rows are stitched with the same focal length setting (the first stitch sets the Wizard value to the detected focal length).

  4. Advance to Wizard 6/9 and place stitching points on one image pair as you did for the first row.  As before, 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.

    Notice that the images have become cockeyed as a result of the manual stitching.  This is caused by variations in camera tilt (pitch axis) and rotate (roll axis) from one image to the next.  This is normal.  We will correct it with the warping grid in the next step.

    Also, notice that the warped images will be wider on the top or the bottom, depending upon whether the row is above or below the center, making a keystone shape for smaller tilt angles or a mushroom shape for larger tilt angles.  This is normal.  The degree of keystoning or mushrooming will depend upon the tilt angle you used for the upper row.

  5. Advance to Wizard 7/9. As in the first row, 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 counter-clockwise from level.

  6. Place a pair of handles (red dots) on vertical lines at the left and right ends of the church.  You do not need to use the same vertical lines that you used for row 1.  Any vertical lines will do.

    As in the first row, we have increased the preview resolution to 50% to help place the handles more precisely.

    After placing the three handles, click Apply warp.

  7. Examine the preview image.  After applying the warp, all vertical lines should be perfectly straight and plumb.   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.

  8. Advance to Wizard 9/9 to complete the stitch and click Done to exit the Wizard.  At this point, you should have a stitched thumbnail and a cropped thumbnail for each row in the upper pane.  The most recent cropped image should appear in the lower pane.

  9. FOR THE BOTTOM ROW ONLY:  When you stitch the bottom row (if it was not the first row you stitched), choose the Panoramic properties command (Image menu).  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.  We'll refer to it as StepAB_Below.

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

Advance to Step C -- Rotate the cropped images 90 degrees clockwise

Back to Step A -- Stitch the first row

Up to The list of the major steps

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Revised: January 11, 2007

 2007 Smoky City Design, LLC and John Strait