Portable electronic device and wound-size measuring method using the same

A portable electronic device, comprising:

• an inertial-measurement unit, configured to detect a pitch angle of the portable electronic device;
• a camera device, configured to obtain an input image;
• a storage device, configured to store an operating system, a wound-measuring program, a CNN (convolutional neural network) model, and an RPN (regional proposal network) model;
• and
• a processor, configured to execute the wound-size measuring program to perform the following steps:
• using the CNN model to recognize the input image, and to select a part of the input image with the highest probability of containing a wound as an output wound image;
• and
• calculating an actual height and an actual width of the output wound image according to a lens-focal-length parameter reported by the operating system, a plurality of reference calibration parameters corresponding to the pitch angle, and a pixel-height ratio and a pixel-width ratio of the output wound image.