image overlay

Accelerated Computing Intelligent Video Analytics DeepStream SDK
1

Hi team,

How can we add image overlay? example logo?

any code samples?

2

Hi,
For more information, you would like to put a logo in JPG/PNG( such as https://en.wikipedia.org/wiki/File:Nvidia_image_logo.svg ) on top-left( or other position ) of the screen?

3

Hi Dane,

Logo yes, also in our case, we detect a red car, etc, we would like to display on the screen.

4

Hi,
The nvosd plugin should be able to mark detected red car in rectangle. Is it not good in your usecase?

5

we need to crop the image and display it on the live screen.

but if you can provide an example of image overlay, we will figure out rest.

6

Hi,
There is no existing implementation for this. We suggest you use NvBufSurface APIs. The APIs offer complete access to the buffers. Please check

deepstream_sdk_v4.0.1_jetson\sources\includes\nvbufsurface.h
deepstream_sdk_v4.0.1_jetson\sources\includes\nvbufsurftransform.h

There is examples of using the APIs in dsexample. Also 2, 5 in FAQ. 2 is a sample of cropping the objects and saving into JPGs. For instant display, maybe you can try to replace cv::imwrite() with cv2.imgshow().

7

This too

8

Hi,
NvBufSurfTransformComposite() can be called to composite a logo on video frames.

You can call cv::imread() to decode JPG/PNG, and put it into a NvBufSurface buffer.

//create a NvBufSurface buffer
NvBufSurfaceCreate();
// get CPU pointer
NvBufSurfaceMap();
cv::Mat source = cv::imread();
/* copy cv::Mat source to the NvBufSurface */
NvBufSurfaceSyncForDevice();
NvBufSurfaceUnMap();

Configure NvBufSurfTransformCompositeParams and call NvBufSurfTransformComposite().