Hi Ashokraj
I understand that you wish to detect objects and count them every 3 seconds instead of 30 times in a single second as you are doing now.
Here an assumption has to be made that the frame rate of the video is 30 frames per second. So in 3 seconds there will be 90 frames. To resolve the issue, in the while loop, introduce a frame counter such that the object detection and counting will be done after every 90 frames. Here is how you can modify your code to achieve this:
clc;
%% Setup of video
vidReader = vision.VideoFileReader('hvsstop2.mp4');
vidReader.VideoOutputDataType = 'double';
mywriter = VideoWriter('mymovie.mp4');
open(mywriter);
%% Structural element
diskelem = strel('disk',2);
hblob = vision.BlobAnalysis('MinimumBlobArea',1500,'MaximumBlobArea',4000);
vidPlayer = vision.DeployableVideoPlayer;
frameCount = 0;
frameSkip = 90; % Number of frames to skip (30 FPS * 3 seconds)
while ~isDone(vidReader)
frameCount = frameCount + 1;
% Read frame
vidframe = step(vidReader);
% Process every 90th frame
if mod(frameCount, frameSkip) == 0
% RGB to HSV color space
I = rgb2hsv(vidframe);
% Define thresholds for channels based on histogram settings
channel1Min = 0.615;
channel1Max = 0.962;
channel2Min = 0.000;
channel2Max = 0.058;
channel3Min = 0.723;
channel3Max = 1.000;
% Create mask based on chosen histogram thresholds
sliderBW = (I(:,:,1) >= channel1Min) & (I(:,:,1) <= channel1Max) & ...
(I(:,:,2) >= channel2Min) & (I(:,:,2) <= channel2Max) & ...
(I(:,:,3) >= channel3Min) & (I(:,:,3) <= channel3Max);
BW = sliderBW;
% Using morphological operations
ibwopen = imopen(BW, diskelem);
% Extract the blobs from the frame
[areaOut, centroidOut, bboxOut] = step(hblob, ibwopen);
% Annotate the detected objects
iannotate_vid = insertObjectAnnotation(vidframe, "rectangle", ...
bboxOut, 'versatilis', TextBoxOpacity=0.9, FontSize=30);
% Play in video player
vidPlayer(iannotate_vid);
% Write to video file
writeVideo(mywriter, iannotate_vid);
else
% Play the unprocessed frame to keep video in sync
vidPlayer(vidframe);
writeVideo(mywriter, vidframe);
end
end
%% Release resources
release(vidReader);
release(hblob);
release(vidPlayer);
close(mywriter);
Hope this helps!
