Panoramas, Three Ways: Part 3

Last panorama assignment! Promise!

Now, you are going to take a panorama and bend it into a circle, creating a “small world” (cue Disney sing-a-long!). But really, this is a wicked way to transform our panos into something totally creative.

(This tutorial is borrowed from the amazing Photojojo site.)


Starting Simple: Planet San Francisco

It’s simplest to work with a 360 degree panorama, so let’s start with this panorama shot of San Francisco taken from the Coit Tower:


Step 1: Resize and Rotate

screenshot1_thumb.jpgThe first thing we need to do is prepare the image for the Polar filter. We do this by stretching the height of the image so that the image is a perfect square.

Select Image>Image Size from the menus. Uncheck ‘Constrain Proporties’ and set the “height” to the same value as your “width”. Next, rotate the image 180 degrees. (Image>Rotate Canvas>180)

You should end up with something like the image to the right.

Step 2: Apply the Polar Filter

Next, we’ll apply the Polar Filter to wrap our image into a sphere.

Choose Filter > Distort > Polar Coordinates from the menus and in the resulting dialog box, select the “Rectangular to Polar” setting.

(If you’re using The Gimp the command is Filters > Distorts > Polar Coords.)

As you can see we’re 90% of the way there!:

Planet San Francisco, almost complete!

Easy cheesy, right? Now for some finishing touches…

Step 3: Rotate and clean up

The rest is just a little digital darkroom work: Rotate the planet to your liking, adjust the contrast and colors, clean up the sky and the edges where the left and right border of the image came together. (The clone stamp and healing brush may be handy here.) That’s it, we’re done!

More Advanced: Planet Venice

Planets work best when created using panoramas, but for this second example we’ll use the following landscape photo of San Girgio Maggiore Island in Venice. Islands are especially well-suited for planetization because the left and right edges of the images are easy to match up–you only have to make sure the horizon is level.


Crop and Straighten

Because we’re not starting with a 360 degree panorama, we’ll need to do some extra work before we can follow the steps above.

First we’ve gotta crop and straighten the image to make the horizon absolutely horizontal. Using the cropping tool of PhotoShop we can do both in one step:

First, we must ensure that our crop selection is parallel to the horizon. Choose the crop tool and select a flat rectangular area of the photo. Move the cursor just outside of an edge of the selected area so that the cursor changes to two arrows pointing left and up. Click the mouse button and you can rotate the cropped area.

By moving the top border of your selection to the horizon of the photo you can inspect the rotation closely. Move and rotate the crop selection until the top border and your horizon are parallel, but don’t crop your photo yet.


Now we want to make sure the left and the right borders of the image fit together. Look for areas on the right and the left where the buildings have the same height:


Move the right and left borders of your selection so that the edges will match up. Finally, adjust the top and bottom of your selection so your waterline is roughly in the middle of the cropped photo:


Double-click your image to commit the crop and you’re ready for the transformation! Just follow steps 1-3 as in the example above.

Here’s the final result:

San Girgio final resultAssignment due May 18, 2012.