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Inside Photoshop, 16 bit values (as explained in your manual) are 0..32768.
In TIFF, 16 bit values are 0..65535.

And your first RGB readout in Photoshop was set to 8 bit, which is 
converting the 16 bit value to an 8 bit value.

0x145e = 5214 [0..65535] = 2607 [0..32768] = 20 [0..255]

3726 [0..32768] = 7452 [0..65535]

29 [0..255] = 7453 [0..65535]

So, not only are you looking at the numbers in different scales, but 
you also made a mistake in measuring the pixel value inside Photoshop.

Chris


AWARE [SYSTEMS]		Imaging expertise for the Delphi developer
		TIFF and LibTiff Mailing List Archive
	LibTiff Mailing List TIFF and LibTiff Mailing List Archive September 2005 Previous Thread Next Thread Previous by Thread Next by Thread Previous by Date Next by Date Contact The TIFF Mailing List Homepage This list is run by Frank Warmerdam Archive maintained by AWare Systems	Thread 2005.09.12 17:12 "extracting 16-bit grayscale from photoshop", by Hoan Chau 2005.09.12 19:12 "Re: extracting 16-bit grayscale from photoshop", by Chris Cox 2005.09.12 19:38 "Re: extracting 16-bit grayscale from photoshop", by Joris Van Damme 2005.09.12 19:12 "Re: extracting 16-bit grayscale from photoshop", by Chris Cox Inside Photoshop, 16 bit values (as explained in your manual) are 0..32768. In TIFF, 16 bit values are 0..65535. And your first RGB readout in Photoshop was set to 8 bit, which is converting the 16 bit value to an 8 bit value. 0x145e = 5214 [0..65535] = 2607 [0..32768] = 20 [0..255] 3726 [0..32768] = 7452 [0..65535] 29 [0..255] = 7453 [0..65535] So, not only are you looking at the numbers in different scales, but you also made a mistake in measuring the pixel value inside Photoshop. Chris

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