Is Photoshop 15+1 format still necessary?

BJ
Posted By
Bill_Janes
Oct 16, 2007
Views
288
Replies
2
Status
Closed
For technical reasons that escape me, Photoshop uses a 15+1 bit format for 16 bit files. A discussion on the Luminous Landscape < http://luminous-landscape.com/forum/index.php?showtopic=1841 3&view=findpost&p=130315> forum has demonstrated that when one brings a 16 bit file into Photoshop, half the values are set to zero. We now have 14 bits in the new Canon and Nikon cameras and 16 bits in many medium format backs. A bit depth of 15 should be ample for any real photographic needs, but limits the use of Photoshop for analysis of true 16 bit images. I would be interested in comments from Chris Cox or other knowledgeable engineering types.

How to Master Sharpening in Photoshop

Give your photos a professional finish with sharpening in Photoshop. Learn to enhance details, create contrast, and prepare your images for print, web, and social media.

RK
Rob_Keijzer
Oct 16, 2007
What I learned from the discussions is that for mathematical reasons there needs to be a central (pivoting) bit.

With true 16 bit that wouldn’t be the case.

That’s where my knowledge about binary stops. I tweak sliders until my image looks good.

Rob

PS, There are 10 kinds of people: the ones that recognise binary notation, and the ones that don’t.
J
Jim
Oct 16, 2007
wrote in message
What I learned from the discussions is that for mathematical reasons there needs to be a central (pivoting) bit.

With true 16 bit that wouldn’t be the case.

That’s where my knowledge about binary stops. I tweak sliders until my image looks good.

Rob

PS, There are 10 kinds of people: the ones that recognise binary notation, and the ones that don’t.
A signed integer a bit which determines the sign of the quantity. An unsigned interger has no such bit.
This is the case for any size integer.

Evidently, PS uses signed integer arithmetic.

Jim

How to Improve Photoshop Performance

Learn how to optimize Photoshop for maximum speed, troubleshoot common issues, and keep your projects organized so that you can work faster than ever before!

Related Discussion Topics

Nice and short text about related topics in discussion sections