Set ROI

Draw over specified region of a video frame stored in external memory

Since R2023a

• 

Libraries:
YOLO v2 Vehicle Detector with Live Camera Input on Zynq-Based Hardware example

Description

The Set ROI block overwrites one or more rectangular regions of a video frame stored in external memory. For instance, you can use this block to display score labels on identified objects. Use this block only in a software interface model connected to an FPGA board that is using the RGB with DL Processor reference design. The block uses the processor-FPGA interface and the memory map of this reference design to read and modify the specified pixels in the frame.

You can only use this block once per model. Your design should provide the ROI coordinates and replacement values and set valid to true once video frames are available in memory. The YOLO v2 Vehicle Detector with Live Camera Input on Zynq-Based Hardware example shows how to use this block in the postprocessing model that is targeted to the ARM^® processor.

Examples

YOLO v2 Vehicle Detector with Live Camera Input on Zynq-Based Hardware

Deploy a YOLO v2 vehicle detection algorithm to the FPGA and ARM processor on an SoC device and process live HDMI video input.

Ports

Input

StartPos — Coordinates of top-left corner of ROI

N-by-2-matrix

Specify the coordinates of the ROIs as a N-by-2 matrix of the form [x y], where N is the number of ROIs, and x y are coordinates of the top-left corner of each rectangle.

Data Types: single | double | uint32

ROI — Replacement pixel values for the region of interest

matrix

Specify the replacement pixel values as a matrix of N-by-width-by-height. All the ROIs must be the same size.

Data Types: single | double | uint32

valid — Enable frame annotation

Boolean

When this input is true (1). the block modifies all frames found in memory. Your design should provide the StartPos and ROI values and set valid to true once video frames are available in memory.

Data Types: Boolean

Parameters

Use row-major format — Read and modify frame buffer in row-major order

on (default) | off

This block assumes the frame is stored in memory in row-major order. If your design stores the frame in column-major order, clear this checkbox.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2023a