vcGetROIData

 Retrieve data within the region of interest (ROI)

   roiData = vcGetROIData(obj,roiLocs,dataType)

 Region of interest data (roiData) are retrieved from the window of any of
 the ISET objects, (SCENE,OPTICALIMAGE,ISA or VCIMAGE).  The ROI
 locations, roiLocs, can be selected using the routine vcROISelect.  These
 are an Nx2 matrix of rows and columns.

 A variety of data types and windows can be chosen. These are:

   scene:         photons (default) or energy
   opticalimage:  photons (default) or energy
   sensor:        electrons or volts (default)
   vcimage:       results (default) or input

 The data are returned in a matrix, roiData.  The rows represent each of
 the positions and the data across the columns represent the values.  The
 number of columns depends on whether the data are wavelength, rgb, or
 electrons. 

 Related:  vcROISelect, sensorGET(isa,'roielectrons');

 Examples:

  vci = vcGetObject('vci');
  roiLocs = vcROISelect(vci);
  result = vcGetROIData(vci,roiLocs,'result');          % Nx3

  For sensor, data are Nx3 and missing values are NaNs

  sensor = vcGetObject('isa');
  roiLocs = vcROISelect(sensor);
  electrons = vcGetROIData(sensor,roiLocs,'electrons'); % Nx3

  scene = vcGetObject('scene');
  roiLocs = vcROISelect(scene);
  photons = vcGetROIData(scene,roiLocs,'photons');      % Nx31

 Copyright ImagEval Consultants, LLC, 2005.