| 607 | 608 | -'''Section planes:''' deducing the physical coordinates from image coordinates requires information on the section plane. The default assumption is that the objects in the image are in the plane used for calibration, but uvmat can handle volume scanning by a laser plane. A set of section planes can be defined by their origin positions and rotation angle vectors. Theses planes are labelled by a ''z index'', assumed to be the frame index j (case of volume scan), or the index i modulo the number of slices !NbSlice (case of 'multilevel' scan). These settings are stored in the xml file <!ImaDoc> as part of the section <!GeometryCalib> and can be edited from '''uvmat.fig''' with the menu bar command '''[Tools/set slice]'''. A dialog box '''set_slices''' appears for entering the first and last section plane positions ''z'', as well as the number of slices and the option 'volume_scan' ('multilevel' otherwise). In the absence of 3D scan put twice the same value for first and last z. Refraction effect can be accounted for if calibration was done in air by introducing the water height (assumed at ''z''=cte). If calibration was already done in water the water height must be '''set with a value below z'''. Finally a tilt angle of the laser sheet, around the ''x'' and ''y'' axis, can be introduced. After introduction of the plane position information, the z-index is displayed in the frame '''[FileIndices]''' of '''uvmat.fig'''. The local ''z'' position of the mouse pointer, assumed to lay on the current section plane, is then displayed in '''[text_display]'''. |
