AIM: Gamma DeepSpace filter

Accurate Image Manipulation for Desktop Publishing

DeepSpace Filter
Filter Name | Density
Compatibility | Adobe Photoshop 5.0 and later.
RGB Workspace | This filter does not require any specific RGB working space.

Description

Provides density conversion. This can be useful in creating a density mask.

To obtain a density mask the density image (result of this plug-in) needs to be Gaussian Blur'ed however calculation of blur in FiFo (or in what ever external plug-in of Photoshop) is very slow, so the filter only provides the density inversion, the rest has to be done in Photoshop.

This filter will provide more consistency and/or easiness to the density conversion compared to the manual work using curves.

Installation | Download and copy all files from the zip archive into the /photoshop/plug-ins directory.

Setup

Open a higher bit-depth image (or convert an 8-bit/channel image to the 15-bit mode, then enter to the filter dialog and press Alt+g to open the Define screen settings -dialog.

Enter the system gamma space that is the gamma value from the Adobe Gamma utility (or from other system calibration utility) not the gamma value from the RGB setup.

This one-time-only step is needed in order to have the image in the preview box to appear correctly.

Sliders | f-stop (.01) | Conversion compression, 0 defaults to 8-bit.
| WP ev(.01) | White-point adjustment in ev. 100 means one ev or one f/stop. -100 means -1ev or -1 f/stop. Use carefully, it will clip when when contracting. Use PV mode to display clipping.
Selection Dropdown | Gray | Result will be a grayscale (but in the RGB space of Photoshop).
Color | Result will be in color. This is a special mode, does not result good quality when the effective bit-depth of the image is below 10-bit.

Usage

To create a density mask, duplicate the image you are working on and apply the Density function. Use the f-stop control to change the compression. Scale the result image up using the WP control.

After the plug-in function the image information is grayscale, but the image mode in Photoshop is RGB. So convert the mode in Photoshop to Grayscale.

In order to blur the image it needs to be converted to 8-bit/channel mode so that the default Photoshop Gaussian Blur can be used.

Author | Timo Autiokari.
Homepage | Accurate Image Manipulation for Desktop Publishing
Usage Right | Free.
Distribution Right | Distribution is prohibited.
Filter Engine | FilterFormula v 1.13, by ATS/Graphics (extended version for 16-bit images).