Change single pixel color in float4 array

Accelerated Computing CUDA CUDA Programming and Performance
1

I’m new to CUDA code. I can do this very simply in C++ using OpenCV:

unsigned int imgWidth1  = 1420;
unsigned int imgHeight1 = 799;
Mat image1(cv::Size(imgWidth1, imgHeight1), CV_8UC4);  //this is later converted to CV_32FC4

//plot simple graph using NumPoints vs Pressure[NumPoints]
unsigned int x = NumPoints + 20;
unsigned int y = 360 - (unsigned int) (3 * Pressure[NumPoints]) + 20;

// get pixel  THIS SECTION IS WHAT I WANT TO REPLACE, REPLICATE USING CUDA FLOAT4
Vec4b color = image1.at<Vec4b>(Point(x,y));
color[0] = 255; color[1] = 255; color[2] = 255; color[3] = 255;  //set pixel to white
// set pixel
image1.at<Vec4b>(Point(x,y)) = color;

But I want to get rid of OpenCV and use a CUDA float4 array for image1. I’m having a lot of trouble figuring out how to do that. It seems like it should just be initializing the float4 with the image size and then calling it with make_float4 to change the pixel. Could anyone please offer a little help?

System: Jetson TX1, Ubuntu 16.04