Figure 2.
Illustration of processing on translucent eggshell spots for 4 kinds of color and 3 ends of eggshell by Grayscale Recognition Method. a: brown shelled; b: pink shelled; c: white shelled; d: blue shelled; a1: eggshell profiles of blunt, sharp and middle ends by candling; a2: translucent spots were painted black manually by Photoshop CC 2018 software to enhance the contrast between translucent spots and opaque areas; a3: all spots on eggshell were extracted by Image-Pro Plus 6.0 software automatically; a4: profiles of the whole eggshells of blunt, sharp, and middle ends.