Fig. 2

Schematic of image analysis. (a) Image of EL autofluorescence captured in the radial-circumferential (r-θ) plane. (b) An analysis line segment was drawn near the marker along the r-axis, toward the center of the image from the marker, to obtain the marker coordinate in the r-axis. (c) A Gaussian function was fitted to the intensity curve along the analysis line in (b). (d) Inverted image of (a). (e) An analysis line segment was drawn on the marker along the θ axis, aligned with the centerline of the EL, to obtain the marker coordinate in the θ axis. (f) A Gaussian function was fitted to the intensity curve along the analysis lines in (e). (g and h) The four makers (i, j, k, l) in (g) real coordinates (r, θ) were converted to (± 1, ± 1) in (h) the imaginary coordinates (ξ, η) before deformation. The same converting function was then applied to the markers after deformation. Strain was first calculated in the imaginary coordinates and then converted to the real coordinates. For details, see Sugita et al.²³.