cmr164
Jan-28-2004, 12:21 PM
There is lots of confusion about TIFF and about RAW so I'll start with JPEG. ;)
JPEG == (Joint Photographic Experts Group) A lossy compressed format supporting 1-24bit depth images. Because of the extreme compression possible, one can have large true colour images that still have a reasonbly small file size and that makes jpegs the web's favourite format. Repeated edits and saves will severely degrade the image because of the loss of information in each cycle.
RAW == A variety of file formats whose common characteristic is that the data of each of the imager sensors is saved. In a classic Bayer Mask sensor the data will be GRGB with 8-16 bits each. On DSLRs the norm is 12bits per sensor. This data may be stored in a proprietary format like Canon's or embedded in TIFFs like the Kodak pro cameras do.
and that brings me to TIFF a subject where what is commonly known is just plain wrong.
TIFF == (Tagged Image File Format) Contains encapsulated image data that can be compressed RAW like the Kodak tiffs or encapsulated uncompressed RGB 8 or 16 bit data (which is what common knowledge thinks of as a tiff) or it can encapsulate any format that is registered. There is even a tiff whose embedded image is a jpeg. The reality is that tiff describes the file format but does not describe the image format.
JPEG == (Joint Photographic Experts Group) A lossy compressed format supporting 1-24bit depth images. Because of the extreme compression possible, one can have large true colour images that still have a reasonbly small file size and that makes jpegs the web's favourite format. Repeated edits and saves will severely degrade the image because of the loss of information in each cycle.
RAW == A variety of file formats whose common characteristic is that the data of each of the imager sensors is saved. In a classic Bayer Mask sensor the data will be GRGB with 8-16 bits each. On DSLRs the norm is 12bits per sensor. This data may be stored in a proprietary format like Canon's or embedded in TIFFs like the Kodak pro cameras do.
and that brings me to TIFF a subject where what is commonly known is just plain wrong.
TIFF == (Tagged Image File Format) Contains encapsulated image data that can be compressed RAW like the Kodak tiffs or encapsulated uncompressed RGB 8 or 16 bit data (which is what common knowledge thinks of as a tiff) or it can encapsulate any format that is registered. There is even a tiff whose embedded image is a jpeg. The reality is that tiff describes the file format but does not describe the image format.