cvview: add c char as calibration

cvview.py

@@ -1,6 +1,7 @@
 import os
 import cv2
 import argparse
+import numpy as np
 
 # Set up the argument parser
 parser = argparse.ArgumentParser(description="Visualize image files and display pixel values on hover.")
@@ -11,6 +12,27 @@ args = parser.parse_args()
 img_path = args.path
 
 
+def calibrate(x):
+    x = x.astype(float)
+    x /= 256.0
+    #print('{}..{}'.format(x.max(), x.min()))
+    ret = ((-1.665884e-08) * x**4.
+        + (1.347094e-05) * x**3.
+        + (-4.396264e-03) * x**2.
+        + (9.506939e-01) * x
+        + (-6.353247e+01))
+    #print('{}..{}'.format(ret.max(), ret.min()))
+    ret = np.where(ret > 0, ret, 0)
+    #print('{}..{}'.format(ret.max(), ret.min()))
+    ret = ret.astype('b')
+    #print('{}..{}'.format(ret.max(), ret.min()))
+    return ret
+
+
+class state:
+    calibrate = False
+
+
 # Function to display the image and pixel values along with the frame index
 def show_pixel_values(image_path):
     def mouse_event(event, x, y, flags, param):
@@ -28,6 +50,8 @@ def show_pixel_values(image_path):
     if img is None:
         print(f"Failed to load image at {image_path}. Check the file path and integrity.")
         return False
+    if state.calibrate:
+        img = calibrate(img)
     cv2.namedWindow('Image')
     cv2.setMouseCallback('Image', mouse_event)
     cv2.imshow('Image', img)
@@ -74,6 +98,8 @@ while True:
         img_path = modify_filename(img_path, increment=False)
     elif key == 93:  # ']' key
         img_path = modify_filename(img_path, increment=True)
+    elif key == ord('c'):
+        state.calibrate = not state.calibrate
 
     # Show the new image
     if not show_pixel_values(img_path):