Revision 3:c57674c348bd, committed 2016-03-30

Comitter:

vsutardja

Date:

Wed Mar 30 01:21:39 2016 +0000

Parent:

2:a8adff46eaca

Child:

4:947c3634b649

Commit message:

Contrast based exposure AGC

Changed in this revision

--- a/main.cpp	Tue Mar 29 23:31:32 2016 +0000
+++ b/main.cpp	Wed Mar 30 01:21:39 2016 +0000
@@ -76,6 +76,8 @@
 // Image processing
 // ================
 int max = -1;
+float lum_bg = 0;
+float contrast = 0;
 int argmax = 0;
 int argmin = 0;
 int temp[128];
@@ -160,7 +162,7 @@
     track();
     
     // Set next frame exposure time
-    camera_read.attach_us(&read_camera, t_int);
+    // camera_read.attach_us(&read_camera, t_int);
 }
 
 // Find line center from image
@@ -169,6 +171,7 @@
 // Calculate and return midpoint of argmax and argmin
 void track() {
     max = -1;
+    lum_bg = 0;
     argmax = 0;
     argmin = 0;
     for (int i = 0; i < 107; i++) {
@@ -197,11 +200,30 @@
         }
     }
     
+    for (int i = 0; i < 30; i++) {
+        lum_bg = lum_bg + img[64 - 10 - i] / 60.0 + img[64 + 10 + i] / 60.0;
+    }
+    
+    contrast = (max - lum_bg) / lum_bg;
+    
+    if (contrast < 1.5) {
+        // Underexposed
+        if (max < 55000) {
+            t_int = t_int + (55000 - max);
+        }
+        // Overexposed
+        if (lum_bg > 25000) {
+            t_int = t_int - (lum_bg - 25000);
+        }
+    }
+    
     if (max > 43253) {
         center = (argmax + argmin + 2 + 11) / 2;
         a = 88 + (64 - center) * 0.625;
         servo = a / 180;
     }
+    
+    camera_read.attach_us(&read_camera, t_int);
 }
 
 // ====
@@ -219,7 +241,7 @@
     
     // Initialize & start camera
     clk = 0;
-//    read_camera();
+    read_camera();
     
     // Initialize motor controller
     motor_ctrl.setInputLimits(0.0, 10.0);
@@ -251,6 +273,6 @@
         d = motor_ctrl.compute();
         motor = 1.0 - d;
         wait(interval);
-        pc.printf("Velocity: %f\r\n", velocity);
+        pc.printf("BG Luminosity: %f, Feature Luminosity: %d, Contrast: %f, Exposure: %d\r\n", lum_bg, max, contrast, t_int);
     }
 }
\ No newline at end of file