overpaint_region🔗
Short description🔗
overpaint_region — Overpaint regions in an image.
Signature🔗
overpaint_region( image Image, region Region, number Grayval, string Type )
Description🔗
overpaint_region paints the regions given in
Region with a constant gray value into the image given in
Image. These gray values can either
be specified for each channel once, valid for all regions, or for each
region separately. To define the latter, group the channel gray values
g of each region and concatenate them to a tuple according to
the regions’ order, e.g., for a three channel image:
[g(channel1,region1), g(channel2,region1), g(channel3,region1), g(channel1,region2), ... ].
If the input image is of type direction, gray values that are not
in the value range that is valid for direction images are set to
the value 255 to mark them as invalid.
The parameter Type determines whether
the region should be painted filled ('fill') or whether
only its boundary should be painted ('margin').
If you do not want to modify Image itself, you can use the operator
paint_region, which returns the result in a newly created image.
Attention🔗
overpaint_region modifies the content of an already existing image
(Image). Besides, even other image objects may be affected: For
example, if you created Image via copy_obj from another
image object (or vice versa), overpaint_region will also modify the
image matrix of this other image object. Therefore, overpaint_region
should only be used to overpaint newly created image objects. Typical
operators for this task are, e.g., gen_image_const (creates a new
image with a specified size), gen_image_proto (creates an image with
the size of a specified prototype image) or copy_image (creates an
image as the copy of a specified image).
Execution information🔗
Execution information
-
Multithreading type: reentrant (runs in parallel with non-exclusive operators).
-
Multithreading scope: global (may be called from any thread).
-
Processed without parallelization.
This operator modifies the state of the following input parameter:
During execution of this operator, access to the value of this parameter must be synchronized if it is used across multiple threads.
Parameters🔗
Image (input_object, state is modified) (multichannel-)image → object (byte / direction / cyclic / int1 / int2 / uint2 / int4 / int8 / real / complex)
Image in which the regions are to be painted.
Region (input_object) region(-array) → object
Regions to be painted into the input image.
Grayval (input_control) number(-array) → (real / integer)
Desired gray values of the regions.
Default: 255.0
Suggested values: 0.0, 1.0, 2.0, 5.0, 10.0, 16.0, 32.0, 64.0, 128.0, 253.0, 254.0, 255.0
Type (input_control) string → (string)
Paint regions filled or as boundaries.
Default: 'fill'
List of values: 'fill', 'margin'
Example🔗
(HDevelop)
* Paint a rectangle into a new image (New1)
gen_rectangle1(Rectangle,100.0,100.0,300.0,300.0)
* generate a black image
gen_image_const(New1,'byte', 768, 576)
* paint a white rectangle
overpaint_region(New1,Rectangle,255.0,'fill')
/* Paint a rectangle into a new image (New1) */
gen_rectangle1(&Rectangle,100.0,100.0,300.0,300.0)\;
/* generate a black image */
gen_image_const(&New1,"byte", 768, 576)
/* paint a white rectangle */
overpaint_region(New1,Rectangle,255.0,"fill")\;
Result🔗
overpaint_region returns 2 (H_MSG_TRUE) if all parameters are
correct. If the input is empty the behavior can be set via
set_system(::'no_object_result',<Result>:).
If necessary, an exception is raised.
Combinations with other operators🔗
Combinations
Possible predecessors
read_image, gen_image_const, gen_image_proto, reduce_domain
Alternatives
set_grayval, paint_region, paint_xld
See also
reduce_domain, set_draw, paint_gray, overpaint_gray, gen_image_const
Module🔗
Foundation