Vision Threshold :: QUARC Targets Library

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Vision Threshold

This block is currently a beta version. If you are using this block, we would appreciate any feedback at tech@quanser.com.

Thresholds a color or grayscale image.

Library

QUARC Targets Beta/Image Processing/Open Source Computer Vision

Description

Vision Threshold

The Vision Threshold block applies fixed-level thresholding to an image. In case of gray threshoding, threshold values are specified in grayscale. For a color image, threshold values are specified in BGR (Blue-Green-Red) intensity levels. The output image shows binary blobs having gray or color values within specified threshold limits.

In order to use this block, be sure to follow the instructions described on the Vision Capture Image page, and take careful note of the limitations.

Input Ports

The number of inputs dynamically changes depending on the specified thresholding operation. The block has two input ports, namely, src_image and gray_th, in case of graylevel thresholding and four input ports, namely, src_image, blue_th, green_th, and red_th, in case of color thresholding.

src_image

A handle to a source image that uses OpenCV (Open Source Computer Vision) IplImage structure. The input may be a color or grayscale image.

gray_th

Threshold limits in grayscale.

blue_th

Threshold limits in blue intensity level.

green_th

Threshold limits in green intensity level.

red_th

Threshold limits in red intensity level.

Output Ports

dst_image

Thresholded destination image in 8-bit binary format.

err

An error signal which is negative in case of invalid memory allocation or usage of invalid parameter values.

Parameters and Dialog Box

Vision Threshold

Threshold type

Specifies the type of thresholding, which is either Gray or Color. The options are described as follows:

                Gray:
                dst_image(x,y) = 255, if lower_gray_limit<src_image(x,y)<upper_gray_limit
                                 0, otherwise

                Color:
                dst_image(x,y) = 255, if lower_blue_limit<blue_plane(x,y)<upper_blue_limit and
                                         lower_green_limit<green_plane(x,y)<upper_green_limit and
                                         lower_red_limit<red_plant(x,y)<upper_red_limit
                                 0, otherwise

Sample time

The sample time of the block. A sample time of 0 indicates that the block will be treated as a continuous time block. A positive sample time indicates that the block is a discrete time block with the given sample time. A sample time of -1 indicates that the block inherits its sample time.

Targets

Target Name	Compatible*	Model Referencing	Comments
QUARC Win32 Target	No	No	Not supported.
QUARC Win64 Target	No	No	Not supported.
QUARC Linux Nvidia Target	Yes	Yes
QUARC Linux QBot Platform Target	Yes	Yes
QUARC Linux QCar 2 Target	Yes	Yes
QUARC Linux QDrone 2 Target	Yes	Yes
QUARC Linux Raspberry Pi 3 Target	Yes	Yes
QUARC Linux Raspberry Pi 4 Target	Yes	Yes
QUARC Linux RT ARMv7 Target	Yes	Yes
QUARC Linux x64 Target	Yes	Yes
QUARC Linux DuoVero Target	Yes	Yes
QUARC Linux DuoVero 2016 Target	Yes	Yes
QUARC Linux Verdex Target	Yes	Yes
QUARC QNX x86 Target	No	No	Not supported.
Rapid Simulation (RSIM) Target	No	No	Not supported.
S-Function Target	No	N/A	Old technology. Use model referencing instead.
Normal simulation	Yes	Yes

* Compatible means that the block can be compiled for the target.