Manual beam width measurement

Created by: HanBrady

Added manual method to estimate beam diameter along x and y axis. Uses fwhm method. This can then be compared with beam width measurement using laserbeamsize. Currently still measured in pixels. Works very well with simulated data but can struggle if signal is too low/ high on real data (true for both manual and lbs methods).

Scripts/manual_comp.py

@@ -9,10 +9,6 @@ import imageio.v3 as iio
 import laserbeamsize as lbs
 from PIL import Image
 
-## Read in image as numpy array
-
-#im_in = Image.open('laser_sim.png') # read in laser data
-#im = np.asarray(im_in) # Could do this in one line with cv2?
 
 ##  Locate peak x and y
 def beam_width_manual(image, axis_in):
@@ -27,31 +23,50 @@ def beam_width_manual(image, axis_in):
     """
     im_in = Image.open(image) # read in laser data
     im = np.asarray(im_in)
-    print(im)
     if axis_in == 'x':
         axis = 0
+        max_point = np.argmax(im, axis) # find coord at peak
+        peak = np.max(max_point)
+        print('peak:', peak)
+        plot = im[peak, :, 0]
+
+        #Plot line of pixels with max
+        plt.plot(plot)
+
+        #determine fwhm
+        max_val = plot[peak]
+        hm = int(max_val/2)
+        hmx = plt.axhline(hm, color = 'black')
+        plt.show()
+
+        index1 = np.where(plot >= hm)
+        index = index1[0]
+        width = index[-1] - index[0]
+        print(f'Beam width (manual) is {width} pixels')
+
     elif axis_in == 'y':
         axis = 1
+        max_point = np.argmax(im, axis) # find coord at peak
+        peak = np.max(max_point)
+        print('peak:', peak)
+        plot = im[:, peak, 0]
+
+        #Plot line of pixels with max
+        plt.plot(plot)
+
+        #determine fwhm
+        max_val = plot[peak]
+        hm = int(max_val/2)
+        hmx = plt.axhline(hm, color = 'black')
+        plt.show()
+
+        index1 = np.where(plot >= hm)
+        index = index1[0]
+        width = index[-1] - index[0]
+        print(f'Beam width (manual) is {width} pixels')
     else:
         raise ValueError('Please input either x or y for axis_in')
 
-    max_point = np.argmax(im, axis) # find coord at peak
-    peak = np.max(max_point)
-
-    #Plot line of pixels with max
-    plot = im[peak, :, 0]
-    plt.plot(plot)
-
-    #determine fwhm
-    max_val = plot[peak]
-    hm = int(max_val/2)
-    hmx = plt.axhline(hm, color = 'black')
-    plt.show()
-    index1 = np.where(plot >= hm)
-    index = index1[0]
-    width = index[-1] - index[0]
-    print(width)
-
     return width
 
 def dithered(image_in):
@@ -81,10 +96,10 @@ def beam_width(image):
     print("The ellipse diameter (closest to vertical) is %.0f pixels" % dy)
     print("The ellipse is rotated %.0f degrees ccw from the horizontal" % (phi * 180/3.1416))
 
-beam_width_manual('laser_beam.jpg', 'x')
-#beam_width_manual('22.07_laserpic3.png', 'y')
+beam_width_manual('laser_sim.png', 'x')
+beam_width_manual('laser_sim.png', 'y')
 
 ## Compare with lbs
 
-image = dithered('laser_beam.jpg')
+image = dithered('laser_sim.png')
 beam_width(image)
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