PanoTransform Photoshop Plug-in v1.0

PanoTransform plug-in rotates mirror ball and panoramic photos in 3D space. PanoTransform translates your 2D mirror ball and panoramic photos into 3D space, rotates the 3D values and then converts it back to a 2D image.

Interface

PanoTransform interface is rather straight forward. Upon loading the plug-in it will check to see if the height and width are close to equal. If they are, it will assume you are working with a Mirror Ball image which usually have equal dimensions. Otherwise the default Input Map option will be set to Panoramic.

The next group of options are the rotation angles. A true panoramic image is like a sphere that has been unwrapped and laid out flat, so rotations don't work in the same way they do in 2D cause the sphere is what is rotated not the flat image. Therefore rotating along the y axis moves the image left to right, z rotates the sphere clockwise or counter clockwise and x rotates the sphere up and down. The y axis is easily noticeable on a panoramic image, but the x and z rotations tend to make it less obvious what is happening but these options can be very useful to level uneven horizons. In mirror ball images these motions are much more obvious cause the mirror ball isn't unwrapped like a panoramic image is. To help with understanding, look at the 3D graph shown imagine something rotating around each of the lines.

No you can always make sure the best part your panoramic is dead center.

Capturing HDR Mirror Ball

One method of obtaining a light probe is to take a high-dynamic range image of a mirrored sphere, such a Christmas ornament.. Assuming your camera is pointing directly at the mirror ball, then in theory a single photograph of the mirrored ball can 'see' in all directions. That is, anything visible from the viewpoint of the mirrored ball will be visible to the camera as a reflection in the ball.

Unfortunately, things that are reflected near the edge of the ball will become extremely stretched and distorted, giving a poor image when it is unwrapped. Additionally, in the center of the ball will be a reflection of the photographer, which will obscure some of the background.

To alleviate these problems, we can take two pictures of the mirrored sphere from different angles and blend them together to remove the camera and the regions of poor sampling.

This is where PanoTransform is absolutely necessary, since the 2 photos are of the same mirror ball. The two 'bad' spots in the mirrored ball are directly towards the camera, and directly away from the camera, the two pictures should be taken from positions 90° apart from each other. This way the regions of bad sampling and camera interference will be in different locations in the two images. (Note that taking the images from opposite sides of the ball will not work, as the region of bad sampling in one image will be the location of the camera in the other image, and vice versa.) So the only thing need to be done in PanoTransform in this case would be to rotate one of the photos either +/- 90 along the y axis.

The final step is to merge these images together using a mask. This now produces a perfect image that can be unwrapped to make a panoramic image. If the 2 images are converted to panoramic images before rotating you will ensure that no data is lost during the final conversion between a mirror ball and panoramic, resulting in better quality final result.