Using the Hough Transform in the Automatization of Contact Angle Calculation

The Measurement of Contact Angle, pH, and Conductivity of Artificial Saliva and Mouthwashes on Enamel, Glass-Ionomer, and Composite Dental Materials

“…The only reason for the delay is that fitting the best radius during circular feature extraction takes a long time. [18,19]. This can be changed by changing the end points of the interval that the algorithm traverses while fitting the radius within the algorithm.…”

“…The contact angle was measured in accordance with our previous reports (Figure 1) [18,19]. All static contact angle experiments were performed at room temperature, 25 • C, using a customized setup.…”

“…Following the preceding step, the algorithm was applied to each image. The algorithm's four main components were as follows: (d) defining a threshold; (e) using morphological transformations to thin out the resulting edges (Figure 3) [18,19]. Even though the Canny edge detector is predominantly used in feature definition, in this algorithm, the Sobel filter was applied in conjunction with a threshold.…”

“…The circle extraction was more complex, as it was designed to search for the best radius and the best coordinates using Equations ( 2)-( 5) and the algorithm described in [18]. This was critical in completely eliminating any user interaction with the image.…”

“…The transformation of the edge image using the Hough transform for the purpose of line detection is shown in Figure 3c. For the purpose of avoiding undefined regions in the k-n parameter space, the transform was implemented in the polar coordinate ρ-ϑ system; Equations ( 6)-( 8) were used for calculating k and n as described in [18]. Afterwards, the extracted line was drawn as a visual representation of the border between substrates.…”