AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

1996.12.07 01:14 "TIFFGetField() colormap entries", by John Lussmyer
1996.12.09 07:28 "Re: TIFFGetField() colormap entries", by Karsten Spang
1996.12.09 13:34 "Re: TIFFGetField() colormap entries", by Iñigo López
1996.12.09 15:46 "nice TIFF viewer", by Sabine Koch
1996.12.09 17:06 "nice TIFF viewer", by Iñigo López

1996.12.09 17:06 "nice TIFF viewer", by Iñigo López

Is there any TIFF viewer out there that really reads and uses the Resolution information of an image? I mean, the viewer whould read the resolution field of a TIFF file, and find out that the image was scanned at 300 dpi, for example. Then, it knows that the monitor has a resolution of 72 dpi (or 96 dpi, or whatever) and rescales the image so that it appears at the correct size. But, if we want to print the image, it will send a full resolution copy to the printer.

This is a nice idea but would you really trust the resolution in the resolution tag? As this resolution can be changed, e.g. for printing purposes you can never be sure that it is really the original scanning resolution saved in this field.

The idea is that every image at the server stores its resolution information. This can be done in many image formats: TIFF, JPEG, PNG, don't know about GIF (probably not), but we will see PNG replacing GIF in a near future anyway.

The client would receive the image and rescale it to the appropiate resolution, but would not modify the original image at the server. What we need here is viewers that care about the resolution field. I am implementing a digital document library for access through a web server which stores the documents as monochrome multipage TIFF images at high resolution (400 dpi and greater). As I haven't found a single TIFF viewer which implements this, the server has to rescale the image to the client's resolution before sending it.

Iñigo