Figure 2
From: 3D surface morphology imaging of opaque microstructures via light-field microscopy
Utilize USAF target to calibrate practical distance of LF microscopy, (a) when USAF target is placed on the focusing, (b) −10 μm related toon focus, (c) −20 μm related toon focus. Each curve is analysed with Tenengrad function, and select different ROI to process, which are group 6 element 1 vertical (G6-E1-V) (blue curve), group 6 element 1 horizontal (G6-E1-H) (red curve), group 7 element 1 horizontal (G7-E1-H) (yellow curve), and group 7 element 1 horizontal (G7-E1-H) (purple curve) as shown in the red dot block area. (d) Plot of alpha-variation versus depth displacement. According to the results from parts (a–c), the best image quality of each ROI is chosen to plot the alpha-variation versus displacement. Linear curve fitting is used to fit the averaged alpha-variation data at different displacements related to the focus position.
