GstCUDA - Example - opencvwarp: Difference between revisions

Revision as of 15:50, 4 September 2020

Introduction

The opencvwarp element will modify an image given a 3x3 transformation matrix. If the demo property of the element is enabled, it will apply a transformation that involves a rotation of the image in a 3D space and then a projection back to the image plane like this:

Figure 1. Opencvwarp demo transformation

Element properties

demo

Put the element in demo mode to showcase it's capabilities. In this mode the incoming image will be rotated in the 3D space and projected back to the image plane. Will override the transformation matrix.
Type: Boolean
Flags: readable, writable
Default: false

m00-m22

The 9 coefficients of the 3x3 perspective transformation matrix.
Type: Double
Range: -1,797693e+308 - 1,797693e+308 Flags: readable, writable
Default: 1

Examples

The following two examples will provide an introduction to the element and its capabilities. Both examples were tested on Nvidia Jetson TX1 and TX2 connected to a display via HDMI and using a webcam as input video source.

Demo example

This example is meant to show the element capabilities. The image will be rotated in three-dimensional space and projected back to the image plane.

By running the following pipeline:

gst-launch-1.0 v4l2src ! nvvidconv ! opencvwarp demo=true ! queue ! nvvidconv ! autovideosink

you should obtain the result shown in Figure 1.

Custom example

Previous: Example: opencv

Index

Next: Example - opencvfilter

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 == Element properties ==
-* '''name'''<br/>
+* '''demo'''<br/>
-Name of the object.<br/>
+Put the element in demo mode to showcase it's capabilities. In this mode the incoming image will be rotated in the 3D space and projected back to the image plane. Will override the transformation matrix.<br/>
-Type: String<br/>
-Flags: readable, writable<br/>
-Default: "opencvwarp0"
-* '''parent'''<br/>
-The parent of the object.<br/>
-Type: GstObject<br/>
-Flags: readable, writable<br/>
-* '''qos'''<br/>
-Handle Quality-of-Service events.<br/>
 Type: Boolean<br/>
 Flags: readable, writable<br/>
 Default: false
-* '''m00'''<br/>
+* '''m00-m22'''<br/>
-Coefficient 0,0 (row, column) of the transform matrix.<br/>
+The 9 coefficients of the 3x3 perspective transformation matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 1
-* '''m01'''<br/>
-Coefficient 0,1 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 0
-* '''m02'''<br/>
-Coefficient 0,2 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 0
-* '''m10'''<br/>
-Coefficient 1,0 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 0
-* '''m11'''<br/>
-Coefficient 1,1 (row, column) of the transform matrix.<br/>
 Type: Double<br/>
 Range: -1,797693e+308 -   1,797693e+308
 Flags: readable, writable<br/>
 Default: 1
-* '''m12'''<br/>
-Coefficient 1,2 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 0
-* '''m20'''<br/>
-Coefficient 2,0 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 0
-* '''m21'''<br/>
-Coefficient 2,1 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 0
-* '''m22'''<br/>
-Coefficient 2,2 (row, column) of the transform matrix.<br/>
-Type: Double<br/>
-Range: -1,797693e+308 -   1,797693e+308
-Flags: readable, writable<br/>
-Default: 1
-* '''demo'''<br/>
-Put the element in demo mode to showcase it's capabilities. In this mode the incoming image will be rotated in the 3D space and projected back to the image plane. Will override the transformation matrix.<br/>
-Type: Boolean<br/>
-Flags: readable, writable<br/>
-Default: false
 == Examples ==