Changes between Version 131 and Version 132 of UvmatHelp


Ignore:
Timestamp:
Jan 13, 2015, 7:56:51 PM (6 years ago)
Author:
sommeria
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • UvmatHelp

    v131 v132  
    231231[[Image(help_scalar_titres.jpg)]]
    232232
    233 The greyscale images are described by a matrix A(npy,npx) of positive integers. The luminosity range depends on the camera dynamics (0 to 255 for 8 bit images, 0 to 65535 for 16 bit images). Luminosity represented with grey levels, according to the colorbar displayed on the right. The luminosity and contrast can be adjusted using the edit boxes '''[num_MinA]''' and '''[num_MaxA]''' : the luminosity level set by '''[num_MinA]''' (and levels below) is represented as black, and the luminosity level set by '''[num_MaxA]''' (or levels above) as white. When the check box '''[!CheckFixScalar]''' is not selected, these bounds are set automatically to the image minimum and maximum respectively. Then the image may appear dark if a single point is very bright, in that case a lower value must be set by '''[num_MaxA]'''. Greyscale images can be displayed with false colors, from blue to red, by unselecting the check box '''[!CheckBW]'''.
     233The greyscale images are described by a matrix A(npy,npx) of positive integers. The luminosity range depends on the camera dynamics (0 to 255 for 8 bit images, 0 to 65535 for 16 bit images). Luminosity represented with grey levels, according to the colorbar displayed on the right. The luminosity and contrast can be adjusted using the edit boxes '''[num_MinA]''' and '''[num_MaxA]''' : the luminosity level set by '''[num_MinA]''' (and levels below) is represented as black, and the luminosity level set by '''[num_MaxA]''' (or levels above) as white. When the check box '''[!CheckFixScalar]''' is not selected, these bounds are set automatically to the image minimum and maximum respectively. Then the image may appear dark if a single point is very bright, in that case a lower value must be set by '''[num_MaxA]'''. Greyscale images can be displayed with false colors, from blue to red, by unselecting the check box '''[CheckBW]'''.
    234234
    235235Note that greyscale images with low resolution are linearly interpolated on a finer mesh for nicer display. This interpolation can be also done as image processing by defining a grid on a projection object 'plane', see [#ProjObject section 6].
     
    237237Two images can be visually compared by switching back and forth between them as a short movie. This is quite useful to get a visual feeling of the image correlation for PIV. This effect is obtained by introducing two image indices in the edit boxes j1 and j2 (or i1 and i2), and selecting the button  '''[movie_pair] ''' (''''[<-->]'''') to switch between these two indices. The speed of the movie can be adjusted by the slider '''[speed]'''. Press '''[movie_pair] ''' again, or '''[STOP]''', to stop the motion.
    238238
    239 Scalar fields are  represented like greyscale images, by default with a false color map ranging from blue (minimum values) to red (maximum), or as gray scale images by selecting the check box '''[!CheckBW]'''. Other color maps can be used by extracting the figure with the menu bar button '''[Export/extract figure]''', then using the standard  Matlab button '''[!Edit/Colormap]''' in the figure menu bar.
     239Scalar fields are  represented like greyscale images, by default with a false color map ranging from blue (minimum values) to red (maximum), or as gray scale images by selecting the check box '''[CheckBW]'''. Other color maps can be used by extracting the figure with the menu bar button '''[Export/extract figure]''', then using the standard  Matlab button '''[!Edit/Colormap]''' in the figure menu bar.
    240240
    241241Scalar are represented by matrices with real ('double') values, unlike images which are integers. They can be alternatively defined with unstructured grid (see [#a5.1Gridingofdata section 5.1]): they are then linearly interpolated on a regular grid before visualisation (a fairly slow process).
     
    244244Scalars (or image intensity) can be also represented with contour plots, by switching the popup menu '''[Contours] ''' from the setting 'image' to the setting 'contours'. Contours for positive scalar values are in sold line while contours for negative values are dashed. The interval between contours can be set by the edit box '''[num_IncrA]'''. The interval is automatically determined if the box content is blank.
    245245
    246 By default, the  contours are further marked by jumps of color levels. This can be set to grey levels by selecting the check box '''[!CheckBW]. '''To suppress these images, set '''[Opacity]''' to 0. '''''''''''
     246By default, the  contours are further marked by jumps of color levels. This can be set to grey levels by selecting the check box '''[CheckBW]. '''To suppress these images, set '''[Opacity]''' to 0. 
    247247
    248248=== 4.3 Vectors ===
    249 The vector fields are represented by arrows. The length of the arrows is automatically set by default, or can be adjusted by the edit box '''[num_VecScale]''' when the check box'''[!CheckFixVectors]''' is selected.  For clarity of visualisation, the number of displayed vectors can be divided by 2 or 4 in each direction by selecting the check box '''[!CheckDecimate4]''', or '''[!CheckDecimate16]''' respectively.
     249The vector fields are represented by arrows. The length of the arrows is automatically set by default, or can be adjusted by the edit box '''[num_VecScale]''' when the check box''' [!CheckFixVectors]''' is selected.  For clarity of visualisation, the number of displayed vectors can be divided by 4 or 16  by selecting the check box '''[!CheckDecimate4]''', or '''[!CheckDecimate16]''' respectively.
    250250
    251251Each vector has a color, ranging from blue to red, which can represent an associated  scalar value. In addition, black and magenta colors represent warning and error flags respectively. This color system is primarily designed for PIV data but can be used in other contexts as well.
     
    434434== 6 - Projection objects == #ProjObject
    435435=== 6.1 Definition and editing with the UVMAT interface ===
    436 These are geometrical objects used to define cuts along lines or planes, to interpolate fields on a regular grid, to restrict the analysis or visualisation to field subregions. The projection of fields on objects is performed by the function ''proj_field.m'', which can be used as well in data processing outside the GUI '''UVMAT''', using for instance [#a10-Processingfieldseries series.fig]).
    437 
    438 When a 2D or 3D field is opened by '''uvmat;fig''', a default projection object called 'plane' is created, so that all field plots (in 2D and 3D) are considered as the result of a projection. New objects are created by the menu bar command  '''[Projection object]''' in '''uvmat.fig'''.  The creation of a new object ('''points''', '''line'''....) can be initiated by selecting the corresponding item in the menu. Alternatively, an existing XML object file can be opened by selecting the menu option '''[browse...]'''. In each case an auxiliary GUI '''set_object.fig''' describing the object properties appears, see next [#a6.2Objectproperties sub-section] for their definitions. This GUI can be directly edited and object coordinates can be set by mouse drawing on the plot, see [#a6.4Objectrepresentation section 6.4]. To validate edition on the GUI '''set_object.fig''', refresh the plots by pressing '''[REFRESH]'''. Objects can be saved as XML files with the (upper right) button '''[SAVE]''' of '''set_object.fig'''.
     436These are geometrical objects used to define cuts along lines or planes, to interpolate fields on a regular grid, to restrict the analysis or visualisation to field subregions. The projection of fields on objects is performed by the function ''proj_field.m'', which can be used as well in data processing outside the GUI '''UVMAT''', using for instance [#a10-Processingfieldseries series.fig].
     437
     438When a 2D or 3D field is opened by '''uvmat;fig''', a default projection object called 'plane' is created, so that all field plots (in 2D and 3D) are considered as the result of a projection. New objects are created by the menu bar command  '''[Projection object]''' in '''uvmat.fig'''.  The creation of a new object ('''points''', '''line'''....) can be initiated by selecting the corresponding item in the menu. Alternatively, an existing XML object file can be opened by selecting the menu option '''[browse...]'''. In each case an auxiliary GUI '''set_object.fig''' describing the object properties appears, see next [#a6.2Objectproperties sub-section] for their definitions. This GUI can be directly edited and object coordinates can be set by mouse drawing on the plot, see [#a6.4Objectrepresentation section 6.4]. To validate edition on the GUI '''set_object.fig''', refresh the plots by pressing '''[REFRESH]'''. Objects can be saved as xml files with the (upper right) button '''[SAVE]''' of '''set_object.fig'''.
    439439
    440440The names of the created objects are listed in the menu '''[!ListObject]'''. The properties of the object selected in this menu can be viewed by activating the check box '''[!CheckViewObject]'''. Check '''[!CheckEditObject]''' to allow object editing with '''set_object.fig'''.  The selected object is plotted in magenta, while the inactive ones are in blue. The field plot resulting from projection can be viewed in the GUI view_field.fig by activating '''[!CheckViewField]'''. This option is automatically selected when a new object is created. Then the projection object used for the main plotting window in UVMAT can be selected by the menu '''[!ListObject_1]''' which reproduces the list of available objects. The active objects are plotted in magenta, while the inactive ones are in blue.The object can be deleted by pressing '''[DeleteObject]'''.