Tutorial 3: Pacific Sunset

Note:  This is a challenging advanced  project which will give you experience in selecting and placing precise marker pairs.

Objectives 

1) use Marker Mode to stitch a partial panorama from photos with few distinctive shared features,

2) transform the panorama using the "Level panorama" feature to straighten and make the ocean horizon horizontal,

3) save a high-resolution master panorama for screen saver or printing and derive a lower-resolution version for web publishing. 

4) 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 exposure to Auto mode. 

2) Tilt the camera to position the horizon roughly in the middle of the frame.  Take overlapping photos handheld while turning around.  Try to stay on one spot as you turn. The overlap is about 40%.  In photo sets with few distinctive features it is important to have adequate overlap.

3) For the photos to this tutorial a consistent panning was not maintained.  The sun photo was taken first, then the two images to the right.  The two images to the left were captured last.  It is generally recommended to pan in one consistent direction, however.

Transfer photos from camera to computer

Load the photos from the camera's memory to the computer in the directory named "sunset".

Open PanoStitcher

 Using PanoGuide, each step of the stitching process is described in the following:

Fig 1. Image Browser in Thumbnail Mode

Load

1) Click on the Stitch Toolbar Load button.  The "Image Browser" window pops up. 

2) Go through the folder hierarchy in the left pane to open the folder "campus".  The middle pane shows all the .JPG files in "campus".

3)  Click on a file name to view its thumbnail image on the right.

4) Click on the "Thumbnail" checkbox to switch Image Browser from Filename Mode to Thumbnail Mode.

5) While pressing [Shift] key, click on 006.JPG and then on 009.JPG.  All files between the two are selected. Click "Load Selections" to load the five selected images to PhotoBench. 

6) Double-click on 005.JPG  in the middle pane to load the image to PhotoBench.  It will appear at the end of the PhotoBench row.

7) Click on 010.JPG in the middle pane and the thumbnail indicates it is also a "sunset" image.  Drag the preview thumbnail to the beginning of the PhotoBench row. 

8) Inspect the thumbnails on PhotoBench.  The order is  010.JPG, 006.JPG, 007.JPG, 008.JPG, 009.JPG, 005.JPG. 

9) Remove 005.JPG by dragging its thumbnail out of PhotoBench, since 005.JPG is not part of "sunset".

10) Sort the remaining five thumbnails by dragging 009.JPG to the spot between 010.JPG and 006.JPG.  Now the order is 010.JPG, 009.JPG, 006.JPG, 007.JPG, 008.JPG.

Fig 2. PhotoBench containing the sorted photo thumbnails

Settings...

1) Click on the Stitch Toolbar "Settings..." button to bring up the "Stitch settings" dialog box.

2) Set Focal length to "Known" and set the value to 28mm (the focal length used for taking this photo set).

3) Select Stitching Mode to "Manual", since "Auto" Mode would have difficulties because the photos are dominated by the moving ocean waves and the static areas (cloud and dark coastline) have few distinctive features.

4) Make sure "Auto-balance intensity" is checked (the photos have different brightness since the camera auto exposure was used)..

5) Click OK.

Stitch

1) Click Stitch.  The window "Adjust Image Pair Overlap" will pop-up for aligning the two images using Overlay method. For this tutorial we will use Marker method (see Tutorial 3 for using Overlay method).  Right-click in the Overlay window and select "Switch to Marker method" to bring up the window "Image Pair for Markers" containing the first two images appears.  A dialog box pops up reminding "Please add minimum 2 marker pairs (press F1 for help)".  Click OK to start adding marker pairs.

2) Inspect the images and choose features that are stable and identifiable in both images.  Refer to the figures below for examples of good marker placement  (You can experiment later to find other appropriate marker placement.)  By clicking try placing  marker 1on the left image as indicated in Fig. 3a.  Be as precise as possible in placing the marker. After adding the marker, use the four arrow keys (<up>, <down>, <right> and <left>) to refine the  marker's location.  Now place a marker on the corresponding spot in the other image.  Repeat the process placing marker 2 in both images.  Now two pairs of markers have been added.

3) Click Stitch.  Or, right-click in the "Image Pair for Markers" window to pop-up its floating menu and choose "Stitch this pair".  The Panorama preview window shows up displaying the stitched images.  Click Stitch again to show the window "Image Pair for Markers" containing the next pair of  images.  Repeat 3) until all image pairs are stitched.

Fig 3a. Image pair 1 & 2: #1 a groove and #2 a bump along the coastline.

Fig 3b. Image pair 2 & 3: in the cloud: #1center of a small piece; #2 gap; #3 junction. 

Fig 3c. Image pair 3 & 4: #1on a gap; #2 junction of several small cloud pieces.

Fig 3d. Image pair 3 & 4: grooves on the outlines of two rocks.

Fig. 4a  Raw panorama preview

Fig. 4b  Panorama preview with ocean horizon straightened and leveled.

4) PanoStitcher already automatically adjusted the photos in the panorama.  However, you might want the ocean horizon to be perfectly straight and level.  Right-click in the panorama preview window to pop-up the floating menu.  Choose "Unbend panorama".  Drag vertically on the panorama to straighten the horizon. Then pop-up the floating menu again to choose "Rotate panorama". Drag vertically on the panorama to level the horizon. 

Blend

1) Choose Resolution Ratio .75 which corresponds to a panorama size of 2789 x 687 pixels. 

2) Click Blend to make the panorama (automatically cropped).

Now the panorama is made!

Edit

1) Make the panorama window just fit inside PanoStitcher's main window (by clicking the Zoom-in or Zoom-out button in the tab bar while pressing the  [Ctrl key). 

2) Click on Main Toolbar Brightness/Contrast button to pop-up the "Brightness/Contrast" menu.  Adjust the Contrast slide bar to enhance the panorama.

3) Right-click in the panorama windown and choose "Select crop region".  Fine-tune the auto-cropped region to your liking by dragging on its sides.  Right-click and select "Crop" to crop the panorama.

Save

1) Click on File | Save Project to save the stitching project to the project file sunset.psp in the "sunset" folder.  Later you can continue working by loading this .psp file to PanoStitcher and clicking Stitch.

2) Click on Main Toolbar "Save image" button to pop-up the "Save Panorama Image" window.  Save the panorama to the name "pano_sunset.tif" which is uncompressed.  This is the master panorama for future use.

3) Right-click on panorama and select "View in PixtraViewer..." to pan and zoom the saved panorama.  You can also view the panorama in Perspective view which will straighten the inherent warping.

4) Click on Main Toolbar ["Print" button to bring up the visual printing utility.  Set page "Orientation" to "Landscape" in Setup | Page Setup dialog box.  Right-click in the panorama window to pop-up the print floating menu and choose "Fit 1x3 Pages".  Click Print to print the panorama to three 8"x11"pages. 

* The three printed pages will need to be taped or glued, and will have visible seams. A better way is to tape or glue three blank papers together before printing, or to buy panorama photo paper (8"x22").  Then in Print setting, choose the proper "paper size" in "Page Setup" and "Fit One Page".  The panorama will be printed to a single long paper.

Post

Click on the "Post" page tab to show PanoGuide Post menu.

1) Right-click on panorama and select "Set as Screen Saver" to pop-up "Display Property".  Select the "Screen Saver" tab.  If Pixtra PanoScreen is the current screen saver, the "pano_sunset.tif" thumbnail preview should already be spinning.  Otherwise you need to select PanoScreen from the screen saver dropdown list.  Click "Settings..." to pop-up "Pixtra PanoScreen Configuration" window.  Change the spin-speed or add the panorama to a PanoAlbum.  Click OK to finish.  In "Screen Saver" menu click OK to set "pano_sunset.tif" as the screen saver of choice.

2) To publish the panorama to your website you need to scale down the master panorama.  Load "pano_sunset.tif" to PanoStitcher. Click on main menu View | "Zoom..." | "Select image size".  Change Width from 2678 to 570 to reduce the panorama to exactly the right size for this web page you are reading. Right-click in the panorama window to pop-up the panorama floating menu.  Select "Save at screen  resolution" to save the reduced panorama as seen on the screen (below is the resultant image).  You can also click on [Web] to automatically generate a dynamic web page using the PanoViewer plug-in.  

Fig. 5  Panorama that is precisely sized for web publishing.