Merge pull request OpenThermal#62 from Bostwickenator/auto_exposure_lock

Auto exposure lock

examples/seek_viewer.cpp

@@ -27,19 +27,52 @@ const std::string WINDOW_NAME = "SeekThermal";
 // Setup sig handling
 static volatile sig_atomic_t sigflag = 0;
 
+
+bool auto_exposure_lock = false;
+
 void handle_sig(int sig) {
     (void)sig;
     sigflag = 1;
 }
 
+
+// Normalize the image so that it uses the full color space available for display. 
+void normalize(Mat &inframe) {
+    static double min =-1, max = -1;
+    static float multiplier = -1;
+
+    if (auto_exposure_lock) {
+        if (min == -1) {
+            cv::minMaxLoc(inframe, &min, &max);
+            multiplier = 65535 / (max - min);
+        }
+        for (int y = 0; y < inframe.rows; y++) {
+            for (int x = 0; x < inframe.cols; x++) {
+                uint16_t val = inframe.at<uint16_t>(y, x);
+                if (val > max) {
+                    val = 65535;
+                } else if (val < min) {
+                    val = 0;
+                } else {
+                    val = (val - min) * multiplier;
+                }
+                inframe.at<uint16_t>(y, x) = val;
+            }
+        }
+    } else {
+        normalize(inframe, inframe, 0, 65535, NORM_MINMAX);
+        min = -1;
+    }
+}
+
 // Function to process a raw (corrected) seek frame
 void process_frame(Mat &inframe, Mat &outframe, float scale, int colormap, int rotate) {
-    Mat frame_g8, frame_g16; // Transient Mat containers for processing
+    Mat frame_g8; // Transient Mat containers for processing
 
-    normalize(inframe, frame_g16, 0, 65535, NORM_MINMAX);
+    normalize(inframe);
 
     // Convert seek CV_16UC1 to CV_8UC1
-    frame_g16.convertTo(frame_g8, CV_8UC1, 1.0/256.0 );
+    inframe.convertTo(frame_g8, CV_8UC1, 1.0/256.0 );
 
     // Rotate image
     if (rotate == 90) {
@@ -77,6 +110,14 @@ void key_handler(char scancode) {
             waitKey(0);
             break;
         }
+        case 'a': {
+            auto_exposure_lock = !auto_exposure_lock;
+            std::cout << "AEL:" << auto_exposure_lock << std::endl;
+            break;
+        }
+        case 'q': {
+            sigflag = SIGINT;
+        }
     }
 }