The Legacy Edition, the m32 Edition and the Mac Editions use .bmp and .tif files.  The x64 Edition uses .pfi files because .bmp and .tiff cannot represent images larger than 2 GB.

Under the Legacy Editions, the m32 Edition and the Mac Edition, when you choose 45-bit image files, image data are stored in individual files with .tiff extensions (double f). These are TIFF (Tagged Image File Format) files with 48 bits per pixel - 16 bits per color. Only the most significant 15 of the 16 bits are used to store image information. The least-significant bit is used for housekeeping information such as noting which areas of a warped image do not correspond to areas of its original, unwarped image.

Under the Legacy Editions, the m32 Edition and the Mac Edition, when you choose 24-bit image files, image data are stored in individual files with .bmp extensions. These are Windows device independent bitmap files with 32 bits per pixel - 8 bits per color. Only 24 bits of each 32 are used to store image information. The additional 8 bits are used for housekeeping information such as noting which areas of a warped image do not correspond to areas of its original, unwarped image.

Under the x64 Edition, .pfi images are used because .bmp and .tiff cannot represent images larger than 2 GB.  The appropriate .pfi format (24 bits per pixel, 36 bits per pixel, or 45 bits per pixel) is chosen automatically by The Panorama Factory depending upon the characteristics of your image data.

Color data stored in .tiff [TBD] files within the project remain unaffected by color correction values. That is, the color correction values affect only the display of the .tiff files.