set_paint — Define the gray value output mode.
set_paint defines the output mode for gray value display
(single- or multichannel) in the window. The mode is used by
Different image types and their possible implication on the
Gray images can also be interpreted as 3D data, depending on the gray value. To view these 3D plots, select the modes '3d_plot'.
Three-channel images are interpreted as RGB images.
Vector field images can be viewed as 'vector_field'.
In most cases the setting
is the most suitable.
Depending on the selected mode, the
Mode may accept a tuple as value.
In these cases the entries can be passed the following ways:
Only the name of the mode is passed: The defaults or the most recently used values are used, respectively.
All values are passed: All output characteristics can be set.
Only the first n values are passed: Only the passed values are changed.
Some of the values are replaced by an asterisk ('*'): The value of the replaced parameters is not changed.
If the current mode is 'default', HALCON chooses a suitable
algorithm for the output of 2- and 3-channel images. No
set_paint call is necessary in this case.
set_paint there are other operators that affect
the output of gray values. The most important of them are
Some output modes display gray values using
region output (e.g., '3d_plot').
In these modes, parameters set with
set_insert influence gray value output.
In case of unexpected results, check the values of the display parameters.
All available painting modes can be queried with
Possible values for
Optimal display on given hardware (default value). Its behavior depends on the number of channels of the input image:
One-channel image: Output the single channel.
Two-channel images: Output the first channel.
Three-channel images: Output as RGB image.
Gray values are interpreted as a 3D height field and displayed using OpenGL. Thereby the different parameters are:
'Mode': Specifies the way in which the height field is displayed. The following modes are supported:
'texture': The height field is displayed as a closed surface and colored using texture mapping. The texture is passed as the second channel (for a gray-valued texture) or as the second to fourth channel (for a colored texture) of the image to display.
'shaded': The height field is displayed as a closed surface and colored using the current LUT.
'hidden_lines': The height field is displayed as a hidden line plot and colored using the current LUT.
'contour_lines': Height lines are extracted and displayed at their actual height. Again the lines are colored using the current LUT.
'Step': Step width, i.e., at what intervals samples in row and column direction are taken from the image. The smaller this parameter is chosen, the finer the resulting height field. However, computation time increases while this parameter decreases. In the case of 'contour_lines' this parameter corresponds to the number of intervals the height range is divided into.
'qa','qb','qc','qd': The four values of a
unit quaternion, describing the orientation of the height field
axis_angle_to_quat for more information on quaternions).
'ZoomFac': Zooming factor, whereby smaller values implicate higher zooming.
'CenterRow', 'CenterCol', 'CenterHeight': Position of the actual center of view defined by row, column, and height. These values must be scaled to the interval [-0.5, 0.5].
Automatic parameter determination:
You can set 'qa' (fourth value in the tuple) or
'ZoomFac' (eighth value in the tuple) to 'auto'.
Then, the zooming factor and the center of view are
determined automatically such that the plot of the height field fills the
window as good as possible.
By setting 'qa' to 'auto', the previous
orientation (or the default one) is kept.
By setting 'ZoomFac' to 'auto',
the provided orientation is used.
It is important that the part of the window is
set correctly (using
set_paint is called.
It is not possible to set any parameters after 'auto' in the tuple.
Furthermore 'auto' will only work correctly if
'scale_plot' is set
to 'true' using
This mode allows interactive display of the 3D data.
For an interactive rate, your graphics card needs to
be powerful enough and support OpenGL. See the operator
update_window_pose for an intuitive way of modifying the
parameters of the 3D plot (e.g., with the mouse).
The colors of the axis are influenced by the colors set using
set_colored. The first
three colors set this way are used as colors for row, column, and height
axis (in this order).
Additional parameters concerning the 3D plot can be set using the operator
If you intend to use '3d_plot' on a Unix-like system, make sure you have sufficient permissions on your graphics device.
Restrictions: Only for one-channel images.
Default: ['3d_plot','shaded',8,0.939,-0.052,0.296, -0.165,0.401,0.072, -0.047,-0.073]
Output a vector field. Thus, for
a circle is drawn for each vector at the position of the pixel.
Furthermore, a line segment is drawn with the current vector.
Thereby the different parameters are:
'Mode': Tells whether the visualized vector fields contain absolute or relative coordinates. Possible values:
'auto' (default): The visualization depends on the semantic type of the vector field.
'absolute': Display vector fields containing absolute coordinates.
'relative': Display vector fields containing relative coordinates.
'Step': Step size for drawing the vectors, i.e., the distance between the drawn vectors.
'MinLength': Minimum length a vector needs in order to be displayed.
'ScaleLength': Scales the vector length.
'CircleSize': Diameter of the drawn circles.
It should be noted that by setting 'vector_field' only the internal parameters 'Mode', 'Step', 'MinLength', 'ScaleLength', and 'CircleSize' are changed. The current display mode is not changed.
Vector field images are always displayed as vector fields, no matter which
Mode is selected with
This results in an output of every 16th vector, that is longer than 2 pixels. Each vector is multiplied by 3 for output..
Restrictions: Only for vector field images.
→(string / integer / real)
Output mode. Additional parameters possible.
Default value: 'default'
List of values: '3d_plot', 'default', 'vector_field'
set_paint returns TRUE if the parameter is correct and the
window is valid. Otherwise an exception is raised.