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Tutorial 1
Tutorial 2
Tutorial 3 Tutorial 4
Tutorial 5
Tutorial 4: Skyscraper
Objectives
In this
tutorial we will show how to:
1) load
images to PhotoBench from Windows Explorer as an alternative to the
"Load Images" window,
2)
transform the panorama using the "Unbend
panorama"/"Rotate panorama" features to make the pyramid
building symmetrical in the panorama,
3)
manually adjust brightness/contrast of PhotoBench images to handle
extreme exposure variations,
4) make a
vertical panorama,
5) save a
high-resolution master panorama for screen saver or printing and derive
a lower-resolution version for web publishing,
6) print
the panorama using the visual printing utility.
Take
the photos
1) Zoom
the lens out to the base focal length of 28mm and set the camera to
auto-exposure. Note if the exposure had been fixed, it would have
been impossible to avoid over-exposure and under-exposure for all the
four images due to extreme contrast variation.
2) Take
overlapping photos handheld while tilting the camera upward. Try
to stay on one spot and keep the camera at the same spatial location as
you shoot upwards to minimize the parallax effect. The overlap is
around 30%.
Transfer
photos from camera to computer
Load the
photos from the camera's memory to the directory in the computer named
"skyscraper" (the file names are changed to skyscraper00x.jpg
for demo convenience).
Open PanoStitcher
Following
PanoGuide, each step of the stitching process is described in the
following:
Load
As the
alternative to the standard loading utility of "Image
Browser", drag-and-drop from Windows Explorer is used here.
Hence close "Load Images" window.
1) Start
Windows Explorer from the computer Start | Programs | Windows
Explorer". Open the folder "tutorial 3/skyscraper"
to show the images:
2)
Select all photos by clicking on the first and then the last image file
name while pressing the [Shift] key.
3) Drag
the four selected images onto PhotoBench.
4) Click
on PhotoBench "Rotate right" button. Click on any image while
pressing [Ctrl] or [Shift] key. All images will rotate 90 degrees
clockwise.
5) Arrange
the images by dragging them to their correct locations on PhotoBench.
6)
Optionally, click Adjust Overlap button on the PhotoBench to pop-up
"Set Image Pair Overlap" window. Drag each overlying
image to roughly register its overlap with its left neighbor. Then
click on top-right [x] to hide the window.
Fig 1.
PhotoBench containing the raw photo thumbnails
Settings...
1) Click
on the Stitch Toolbar "Settings..." button to bring up the
"Stitch settings" dialog box.
2) It is
known that at the focal length (28mm) of the camera used in this example
there is substantial distortion towards the periphery of an image, which
needs to be corrected for stitching. Click on the "Enable"
check box to activate the "Select..." button. Click on
the button to pop-up the "Select Camera Info" dialog box.
Select the Camera Info file "Olympus C-3000 (28mm).txt" and
Click OK.
3) The
default stitching "Auto Mode" should already be selected.
4) Check
"Auto-balance intensity".
5) Click
OK.
Stitch
1) Click
on the Stitch Toolbar [Stitch] button. PanoStitcher will stitch
all image pairs to make the panorama preview.
2) Inspect
the panorama preview. All images are properly registered, but the
building seems "crooked". Right-click on the panorama
and choose "Unbend panorama". Drag vertically on the
panorama to make the pyramid more symmetrical. Then pop-up the floating
menu again to choose "Rotate panorama". Drag vertically
on the panorama to level the pyramid.
Fig. 2a
Panorama preview
Fig. 2b
Panorama preview: unbent/rotated
Blend
1) Change
Resolution Ratio from default .75 to .50 to speed up blending process.
This ratio corresponds to a panorama size of 637 x 302 pixels.
2) Click
Blend button to make the auto-intensity balanced panorama
(auto-cropped)..
Inspecting
Fig. 3, the intensity transition is great but the ground level is too
dark. The reason is that the scene has extreme brightness
variations and the auto-balancing's job is to make smooth intensity
transitions. But you might care more about the visibility of all
scene areas. You can exert your preference using the manual
intensity balancing tool.
Fig. 3
Panorama: with auto-intensity balancing
3) Click
"Settings...". Uncheck "Auto-balance intensity".
4)
Right-click on PhotoBench image #2 to pop-up the floating menu. Choose
"Adjust Brightness/Contrast". The Brightness/Contrast
menu shows up. Move the Brightness and Gamma the sliders to the
right and the Contrast slider to the left to promote the overall
brightness while reducing the contrast. Click on image #3 to
connect it to the "Brightness/Contrast" menu and adjust.
Repeat the process with image #4. No adjustment is made for image
#1. The settings of all four images are shown below. The
goal is to provide good visibility of features in each image and in the
meantime to try to balance the intensities in each pair's overlap area.
The effect on the images is shown in Fig. 5b.
Fig. 4
Manual-intensity adjustment settings of the four PhotoBench images.
Fig 5a.
PhotoBench containing the raw photo images
Fig 5b.
PhotoBench after manual brightness/contrast adjustments
4) Click
Blend.
5) Repeat
Step 3), experimenting with settings, and 4) until a satisfactory result
is achieved. Then increase the Resolution Ratio to 75% to make the
master panorama.
Now
the panorama is made!
Fig. 6
Panorama with manual-intensity adjustments
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