update the threshold values (#170)

* update the threshold values

* Refactor: applied named constants (MSE, SSIM, FLOW thresholds) in constructor init

Author: r83575

src/deepstream/probes/frame_comparison/gpu/frame_change_detector.cpp

@@ -5,9 +5,13 @@
 #include <cmath>
 #include <vector>
 
+const double MSE_THRESH = 20.0;
+const double SSIM_THRESH = 0.998;
+const double FLOW_THRESH = 0.5;
+const double OPTICAL_FLOW_ACTIVE_THRESH = 0.5;
 
 GPUFrameChangeDetector::GPUFrameChangeDetector()
-    : mse_thresh(500.0), ssim_thresh(0.99), flow_thresh(2.0), initialized(true) {}
+    : mse_thresh(MSE_THRESH), ssim_thresh(SSIM_THRESH), flow_thresh(FLOW_THRESH), initialized(true) {}
 
 static cv::Scalar mean_gpu(const cv::cuda::GpuMat& mat) {
     cv::Scalar sum_val = cv::cuda::sum(mat);
@@ -80,7 +84,7 @@ double GPUFrameChangeDetector::optical_flow_gpu(const cv::cuda::GpuMat& imgA, co
     cv::cuda::cartToPolar(flow_xy[0], flow_xy[1], mag, angle, true);
 
     cv::cuda::GpuMat active_mask;
-    cv::cuda::threshold(mag, active_mask, 0.5, 1.0, cv::THRESH_BINARY);
+    cv::cuda::threshold(mag, active_mask, OPTICAL_FLOW_ACTIVE_THRESH, 1.0, cv::THRESH_BINARY);
 
     cv::cuda::GpuMat active_pixels;
     mag.copyTo(active_pixels, active_mask);
@@ -108,7 +112,7 @@ GPUFrameChangeDetector::should_process_gpu_direct(const cv::cuda::GpuMat& gpu_fr
     double ssim_val = simple_ssim_gpu(prev_frame_gpu, processed_curr);
     double flow_val = optical_flow_gpu(prev_frame_gpu, processed_curr);
 
-    bool is_static = (mse_val < 10.0 && ssim_val > 0.995 && flow_val < 0.05);
+    bool is_static = (mse_val < mse_thresh && ssim_val > ssim_thresh && flow_val < flow_thresh);
 
     bool should_proc = !is_static;
     if (should_proc) {