16 bits per channel

[GM1968]

Hello,

How to enter a color value on 16bits?

The value for RVB is on 8 bits (0-255)... we should be able to enter a value between (0-65535)... but How ?

[Juan]

Check the small checkox (Extended range) in the color editor.

Range.jpg

Cheers
Juan

[bkh]

Hello,

How to enter a color value on 16bits?

The value for RVB is on 8 bits (0-255)... we should be able to enter a value between (0-65535)... but How ?

You can use fractional numbers (e.g. 5.713) to specify intermediate colours, however the dialogue only shows integer values. You'll get higher precision if you have the values displayed as floats or as a percentage (via the context menu of the text boxes). Unfortunately, there are still a few places in PL where values aren't displayed in the same precision that PL uses internally.

Check the small checkox (Extended range) in the color editor.

"Extended Range" only gives colours below black or above white (this only makes sense if you have 32 bit colour depth which uses floats).

Cheers

Burkhard.

[GM1968]

Thank you !

When you create a color gradient: I feel that the intermediate colors are not used?

[bkh]

When you create a color gradient: I feel that the intermediate colors are not used?

PL definitely uses intermediate colours – the attached sample file has a gradient from RGB(0,0,0) to RGB(1,2,3) created by the gradient tool and a gradient vector layer. The histogram adjustment layer above shows that the transition is smooth.

Cheers

Burkhard.

[ellhel]

Hi,

the "Map" looks a little "funny" . Is this normal.

Regards
Helmut

[GM1968]

When you create a color gradient: I feel that the intermediate colors are not used?

PL definitely uses intermediate colours – the attached sample file has a gradient from RGB(0,0,0) to RGB(1,2,3) created by the gradient tool and a gradient vector layer. The histogram adjustment layer above shows that the transition is smooth.

Cheers

Burkhard.

Great

Yes but, in screen with zoom, you can clearly see limits of each color range. This is a problem that can be found everywhere (also in Photoshop). For correct the "banding" of gradient we need to blur and add noise...

[bkh]

the "Map" looks a little "funny" . Is this normal.

Looks like the map only uses 8 bits of colour depth – switch the background layer to 8 bit colour depth and the main image will look the same (depending on the antialiasing settings of the two layers, you'll see four broad bands or dithering). I'm not sure if this is a bug or an efficiency measure.

Cheers

Burkhard.

[bkh]

Yes but, in screen with zoom, you can clearly see limits of each color range. This is a problem that can be found everywhere (also in Photoshop). For correct the "banding" of gradient we need to blur and add noise...

Sorry, but I can't see any banding – if you look at the colour values, the gradient is as smooth as possible, and shouldn't change if blurred. Of course, the difference between two adjacent pixels can still be visible, especially when the transition is along a straight line, but that doesn't have anything to do with colour depth but with image resolution. Such "lines" tend to be less visible if there is some noise. If you see severe banding, it's probably because of the lookup table in your graphics card – in that case, the location of the bands will change if you choose a different display profile.

Cheers

Burkhard.

[Herbert123]

Don't forget that most flat screens have a quite poor colour gamut (range) and although internally the gradient is absolutely smooth, banding may occur due to the screen's technical limitations.

[ellhel]

the "Map" looks a little "funny" . Is this normal.

Looks like the map only uses 8 bits of colour depth – switch the background layer to 8 bit colour depth and the main image will look the same (depending on the antialiasing settings of the two layers, you'll see four broad bands or dithering). I'm not sure if this is a bug or an efficiency measure.

Cheers

Burkhard.

OK....Thanks

[Hoogo]

Yes but, in screen with zoom, you can clearly see limits of each color range. This is a problem that can be found everywhere (also in Photoshop). For correct the "banding" of gradient we need to blur and add noise...

Sorry, but I can't see any banding – if you look at the colour values, the gradient is as smooth as possible...If you see severe banding, it's probably because of the lookup table in your graphics card – in that case, the location of the bands will change if you choose a different display profile.

For a test I ceated a picture of 16Bit, 1024 pixels, and placed a vector with gradient above it. A screenshot with added histogram correction shows bands with a width of 4 pixels. I'm pretty sure that the output to the screen once has been dithered, and now it isn't anymore. Banding effects are a common topic in every forum, and a while ago I simply blamed Photoshop for it.

[bkh]

For a test I ceated a picture of 16Bit, 1024 pixels, and placed a vector with gradient above it. A screenshot with added histogram correction shows bands with a width of 4 pixels. I'm pretty sure that the output to the screen once has been dithered, and now it isn't anymore. Banding effects are a common topic in every forum, and a while ago I simply blamed Photoshop for it.

I still get dithered screen output here (OS X 10.8.5), regardless of the antialiasing setting of the vector layer, but I'm not sure if the dithering is done by PL or by OS X. Perhaps you can upload your PL file? Anyhow, this is just a display issue.

Cheers

Burkhard.

[Hoogo]

For a test I ceated a picture of 16Bit, 1024 pixels, and placed a vector with gradient above it. A screenshot with added histogram correction shows bands with a width of 4 pixels. I'm pretty sure that the output to the screen once has been dithered, and now it isn't anymore. Banding effects are a common topic in every forum, and a while ago I simply blamed Photoshop for it.

I still get dithered screen output here (OS X 10.8.5), regardless of the antialiasing setting of the vector layer, but I'm not sure if the dithering is done by PL or by OS X. Perhaps you can upload your PL file? Anyhow, this is just a display issue.

Cheers

Burkhard.

The smaller layer was cropped from a screenshot of the picture without the histogram correction.

[GM1968]

Hell...That may be produced by my graphics card or my monitor.
AMD RADEON HD 6700
SAMSUNG SyncMaster F2280

Otherwise you can do like that : http://www.iceflowstudios.com/2013/tips ... dithering/