2006.09.15 15:49 "Re: [Tiff] is there alpha component present in Grayscale or Palettecolor image", by Gerben Vos

I'm trying to handle tiff images with alpha component, so i want to know that any tiff image which is Grayscale or Palette color can have alpha component.

It is possible for greyscale, just use the ExtraSamples tag as defined in section 18 of the TIFF spec. It is not possible for palette images; the ColorMap tag uses a fixed format with exactly three values per entry.

Gerben Vos.