5.3.6.4 X Gamut Tool
X Gamut Tool Function:
The Gamut Tool provides an interface to the CME Gamut Mapping
programs and allows the user to preview the results of particular
mappings on a sample subimage. The tool provides several methods
of specifying gamut expansion and contraction parameters and allows
for viewing the results of multiple mapped images. The original
subimage is provided as a comparison with the mapped images.
The methods for specifying map parameters are the following: User
Specified where the user enters the parameters; Neural Net Suggestions
where the Neural Net knowledge base of image features and applied
map parameters determines an appropriate set of map parameter; Search
Parameter Range where a matrix of a range of parameters can be examined;
Visual Comparison Search where the corner parameters of a parameter
area are progressively examined with the user interactively selecting
the next corner of the area to search.
The Gamut Tool can be run as a stand-alone program or can be
initiated through the ColorTool within Xid. When run stand-alone,
the parameters to the program are
XGamutTool preview_image full_image
dltfentry
X Gamut Tool Performance:
The X Gamut Tool requires significant system resources in acheiving
the desired preview capability. When running X Gamut Tool from Xid
it is recommended that Xid be initiated on a server system with
significant memory (48MB+) and swap space (128MB+). Also, when
running standalone on a workstation, ensure that minimal extraneous
processing is being performed. The current version of the X Gamut
Tool is optimized for the Visual Search capability. An RPC server,
gamut_server is started when the image is selected. If User Selected
or Search Parameter Range options are to be run, the gamut_server
process can be terminated by using the Terminate Command
button on the message window after the server ready prompt.
Preview Image Name:
This button and input text field provide a mechanism for specifying
the file name of the LAS image to be previewed. By pressing the
push button, a file browser will be displayed to allow selection of
the image file, or the name of the file can be entered in the text
field directly. If executed from Xid, this field will be entered
from the name of the Full Resolution or Main Window image saved
for previewing. Note that for performance purposes, the preview
image should be no larger than 1024x1024. Also, it is recommended
that the Input Model and Output Model be verified prior to selecting
the Image Name. In this manner, the conversion from the LAS file
to CIE space is only done once.
Gamut Map Parameter Selection Toggles:
This specifies the method for selection the map parameters.
When additional input is required for the option, additional entry
fields are added to the form for the option. Press the Apply
button to initiate the process for the options specified.
Input/Output Model Option Buttons:
These option buttons allow for specification of the input and
output models for the gamut mapping. The Input Model will primarily
be the model for the display where the image was manipulated with
Xid. The output model should specify the printer device model.
The list of models used to set the options is found in
$CMEMODELDIR/Models. The default output model is the first model
in this file.
Gamut Map Mode Toggles:
The Gamut Map Mode can be either spherical or cylindrical and
describes the coordinate system used in applying the gamut map
expansion and contraction parameters.
Apply Button:
The Apply button processes the current option settings and invokes
the appropriate gamut mapping functions on the preview image. The
functions invoked and the messages from those functions are displayed
in the message window. Note that these functions do require
significant processing and as such response from these functions
will vary from 1 minute to longer depending on options selected.
Create PDF Button:
When the "best" set of map parameters have been determined, use the
Create PDF button to create a LAS parameter definition file with
the necessary parameter to map the image to the output device.
The PDF file will be named based on the image name appended by
".pdf".
Dismiss Button:
The dismiss button terminates processing of the X Gamut Tool.
User Specified Gamut Map Parameters:
Sliders and text entry fields are provided for specifying the Gamut
expansion and contraction parameters in the range from .01 to 1.0.
The Measure Distortion toggle specifies an additional step to
calculate the distortion from the original image. Weigting parameters
can be entered to weight luminance, saturation and spatial energy
image feature differently in the distortion calculations. Weighting
parameter default to 1.0 and can range from 0.0 to 10.0.
Search Range Parameters:
Sliders and text entry fields are provided for specifying the range
and steps of map parameters to test. The steps range from 2 to 100
and include the start and end values. This allows are large
number of possible images to be mapped. Distortion is calculated
for each image, and the list of images is displayed in increasing
order of distortion. Weighting parameters can be specified to
change the calculation of the distortion. In order to view a
mapped image from the list, select the entry from the list and
press OK. The image will be converted to RGB space for viewing
and this process may take several minutes.
Neural Net Suggestion:
The Neural Net is invoked to examine the image and provide a
set of map parameters appropriate for the image. The parameters
returned include the map type (spherical or cylindrical), and the
map expansion and contraction values. These can be used as
User Selected parameters to preview the image, or can provide
starting points for a visual comparison search.
Visual Comparison Search:
The map parameter range corner points are used to generate a display
of four images at those map paramaters. The user can visually
determine the best image and click on the image desired. The
parameter will be updated to a new quadrant containing the selected
image and three new points at half the previous parameter corners.
Presssing Apply initiates the next display. When the best image has
been found, use the Create PDF button to generate the LAS script
file for those parameters.
Create PDF:
This button will generate a small LAS script which will perform
a mapping and gamut transformation for the original image using the
mapping parameters chosen in the gamut tool.
Gamut Tool Message Window:
This window provides an interface to display the results of scripts
executed by the gamut tool. The Terminate command button allows
a long executing script to be terminated. Some manual cleanup will be
required after termination.
Dismiss:
The Dismiss button terminates the map tool window.