Panoramic Preview Resolution Comparison

The following cubic panoramas were made with different resolutions for the preview. They were all done in gray scale, with the JPEG compressor at 75% quality, with no additional blurring. The source panorama is 2.2 pixels per degree (256x256 faces).

0.13 pixels per degree

0.25 pixels per degree

0.5 pixels per degree

1.0 pixels per degree

2.0 pixels per degree

Note that the cubic QuickTime VR plug-in bilinearly interpolates the preview pixels up to the full resolution. This implies that the apparent resolution of a 0.5 pix/° preview is the same as that of a 1.0 pix/° preview that has been blurred, but uses only one quarter the number of pixels. The bytes thus saved can instead be used to increase the quality of the compression. The standard preview quality is 25%, but these previews have a quality of 25%.

Cylindrical panoramas still block-replicate the preview pixels, so the quality is still better with more blurry pixels. This may be changed in the future.

The cubic panorama used in these comparisons is courtesy of Terry Breheny / Digital Zen.