Changes between Version 85 and Version 86 of UvmatHelp

Timestamp:

Jul 5, 2013, 11:12:39 AM (11 years ago)

Author:

sommeria

Comment:

--

UvmatHelp

@@ -581 +581 @@
 -''' Editing the coordinate table: ''' After mouse selection, the physical coordinates  must be introduced by editing the table. To make this task easier it is possible to export the table content on the Matlab command window by pressing '''[COPY PTS]''', and copy-paste a column on the table '''[!ListCoord]''' (the column below the introduction cell is filled). A single point can be removed by the 'backward' or 'suppr' keyboard command after selecting its line on the table. The whole set of points can be removed by pressing '''[CLEAR PT]'''. They can be also removed by pressing '''[STORE PT]''', then stored in a xml file (whose path and name is listed in '''[!ListCoordFiles]'''). Stored points can be retrieved by the menu bar command '''[Import/calibration points]'''.
 
--''' Creating a physical grid: ''' This tool '''[!Tools/Create grid]''' in the  menu bar command provides the whole set of physical coordinates of a cartesian grid, after all their image coordinates have been picked out by the mouse. In the  GUI '''Create_grid.fig''' which appears, set the first and last x and y values and the meshes for the physical grid corresponding to the points already selected by the mouse. The physical coordinates of all the grid points then appears on '''[!ListCoord]'''.
+-''' Creating a physical grid: ''' This tool '''[!Tools/Create grid]''' in the  menu bar command provides the set of physical coordinates of a cartesian grid, ranked line by line from the bottom. First pick the set of image coordinates with the mouse. Then launch  '''[!Tools/Create grid]''' and fill the first and last x and y values, as well as the meshes, in physical coordinates. These coordanates then fill '''[!ListCoord]'''.
 
 -''' Detecting a physical grid: ''' This tool '''[!Tools/Detect grid]''' provides the same result as '''[!Tools/Create grid]''', but it automatically recognises the grid points on the image, provided the four corners of the grid have been previously selected by the mouse. The calibration points are detected either as image maxima (option 'white markers'), or as black crosses (option 'black markers'). Their position can be adjusted by selection with the mouse.
@@ -593 +593 @@
 Alternatively the command '''[REPLICATE]''' can be used to calibrate a whole set of experiments, using an overview of the data set provided by the GUI '''data_browser.fig'''.
 
--'''3D calibration''': take a set of (typically 5-10) calibrations images using a grid with different tilting angles (for precision the grid must cover a large area of the view field). On each image, get calibration points with the tool '''[!Tools/Detect grid]''', introducing the appropriate grid mesh, then apply calibration with the option 3D_linear or 3D_quadr (if non-linear distortion is significant). Store the points each time, which fills the list [ListCoordFiles] of file names. 
+-'''3D calibration''': take a set of (typically 5-10) calibrations images using a plane grid with different tilting angles (for precision the grid must cover a large area of the view field). On each image, get calibration points with the tool '''[!Tools/Detect grid]''', introducing the appropriate grid mesh. Do not fill info on ''z'' coordinates. Store the points each time (without applying calibration at this stage), which fills the list [ListCoordFiles] of file names. Then introduce a last grid image which will be considered as defining the orientation of the ''z'' axis, perpendicular to the grid. Detect points on this last image, but instead of storing them, apply the calibration with the option 3D_linear or 3D_quadr (if non-linear distortion is significant). The ''z'' position chosen for this reference calibration plane can be indicated at this stage.
+
+-'''Intrinsic parameters''': the previous procedure first determines the extrinsic parameters which characterize the camera optics (focal lengths and nonlinear deformation parameter). Then the extrinsic parameters, translation and rotation of the camera with respect to the reference grid, are determined on the last grid image. if the same optics is used in a new experiment, it is possible to skip the multiplane detection, importing the intrinsic parameters from a previous <!ImaDoc> file by the menu bar tool '''[!Import/Intrinsic]''' parameters, then applying the calibration with the option '3D_extrinsic' with the reference grid image only.
 
 === 8.3 Structure of the xml file ===
@@ -600 +602 @@
  * <!CalibrationType>: type of calibration ('rescale', 'linear', '3D...')
 
- * <fx_fy>: focal length along each coordinate of the image sensor, expressed in pixel interval.
-
- * <Cx_Cy>: position coordinates of the optical axis on the
-
- * <kc>: coefficient of quadratic deformation (=1 for the options calib_lin and calib_rescale)
+ * <fx_fy>: focal length along each coordinate of the image sensor, expressed in pixels/cm.
+
+ * <Cx_Cy>: position coordinates of the optical axis on the image sensor.
+
+ * <kc>: coefficient of quadratic deformation (=0 for the options calib_lin and calib_rescale)
 
  * <!CoordUnit>: coordinate unit in physical space.
@@ -610 +612 @@
  * {{{<Tx_Ty_Tz>}}}: translation, (Tz=1 for the options calib_lin and calib_rescale)
 
- * {{{<R>}}}: rotation matrix (in 3 lines). For the option <[https://servforge.legi.grenoble-inp.fr/projects/soft-uvmat/search?q=wiki%3ACalibrationType CalibrationType]>= 'rescale', [[BR]] R (i=1)= [pxcmx 0 0] R (i=2)= [0 pxcmy 0] R (i=3)= [0 0 1], [[BR]]where pxcmx and pxcmy are the scaling factors along x and y.
+ * {{{<R>}}}: rotation matrix (in 3 lines). For the option <[https://servforge.legi.grenoble-inp.fr/projects/soft-uvmat/search?q=wiki%3ACalibrationType CalibrationType]>= 'rescale', [[BR]] R (i=1)= [pxcmx 0 0] R (i=2)= [0 pxcmy 0] R (i=3)= [0 0 1], [[BR]]where pxcmx and pxcmy are the scaling factors along ''x'' and ''y''.
 
  * <omc> 3 components of the rotation vector (this is for diagnostic use, it is redondant with the matrix R used for actual coordinate transforms).  The physical coordinate axis are transformed to the image coordinate axis by a composition of the translation T and the rotation)
 
- * <ErrorRms>: rms difference (in X and Y direction) between the image coordinates measured for the calibration points and the coordinates transformed from their physical coordinates (using the function ''px_XYZ.m in uvmat'')
+ * <!ErrorRms>: rms difference (in X and Y direction) between the image coordinates measured for the calibration points and the coordinates transformed from their physical coordinates (using the function ''px_XYZ.m in uvmat'')
 
  * <!ErrorMax> : maximum difference (in X and Y direction) between the image coordinates measured for the calibration points and the coordinates transformed from their physical coordinates. (using the function ''px_XYZ.m'' in uvmat)
@@ -620 +622 @@
  * <!SourceCalib> set of the point coordinates used for calibration
 
- * <!PointCoord> [x y z X Y] , where x,y,z are the physical coordinates of each point, X Y its image coordinates
+   * <!PointCoord> [x y z X Y] , where x,y,z are the physical coordinates of each point, X Y its image coordinates
 
  * <!NbSlice_i> nbre of slices for the first field  index i (multilevel case), =1 by default.