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.