*2.2. Apple Image Acquisition and Data Augmentation* 2.2.1. Image Acquisition

The apples used in this dataset are "Fengxian apples" from Xuzhou City, Jiangsu Province, and "Yantai apples" from Yantai City, Shandong Province, which are among the representative brands of red Fuji. The sources of apples include purchases from apple markets and picking from orchards. The image acquisition equipment used in the experiments is a CCD industrial camera, MER2-G. The camera was mounted on a bracket above a lampshade with a 90◦ angle of view directly above the flip mechanism and a fixed height of 70 cm. The lampshade was illuminated with a LED strip as a fill light source to capture images of apples under diffuse lighting. A final dataset of 2000 apple images was obtained, including grade-1, grade-2, and grade-3 apples. The grade-1 and grade-2 apples were mainly purchased from the market (differentiated by price), while grade-3 apples were marketed in smaller quantities, mainly from orchard picking. The CCD industrial camera uses a GigE interface for data transmission and acquisition with an industrial computer. The image resolution is 1280 × 1024, the pixel size is 4.5 × 4.5 μm, and the operating temperature range is 0◦ to 45◦. The camera is installed according to the position of the flipping mechanism, the shooting angle is 90◦ directly above the flipping mechanism, the shooting height is a fixed value of 70 cm, and the image acquisition of the apple is carried out on the flipping mechanism, the image acquisition method and the image acquisition effect are shown in Figure 6.

**Figure 6.** Data set production. (**a**) Image acquisition devices; (**b**) Image acquisition.
