1. What are spots?

Spots are small, flat dark areas on the skin. They usually range in color from light brown to black and are mainly located in areas most exposed to the sun, particularly the face and neck. Spots generally start to appear from the age of 40 and become common in adults in their fifties, but younger people can also get spots if they spend time under the sun. Although spots are harmless, most people prefers to have them lightened or removed due to the unsightliness. Frequent causes of spots include:

• Sun exposure (leading cause)
• Inflammation, such as acne, eczema, allergic reactions
• Melasma, happening mainly during pregnancy
• Medication side effects

Table. 1 Representative images of spots detection and classification

Captured Image	Analyzed Image

2. ChoiceTech spots grade

The following ChoiceTech spots grade has been co-developed by ChoiceTech and dermatology experts. For each image, we detect spots to provide a quantified score. An expert approved questionnaire is also included, as an option, in order to understand a customer's lifestyle and habits and obtain a fuller profile of the customer's skin. Taking into account the questionnaire results, the final score for skin spots is computed as the weighted average of the image score and questionnaire score. In case that questionnaire is skipped, only image score will be used. Based on the scale shown in Table 1, we grade skin spots into excellent, good, moderate, poor and very poor.

Table 2. Skin spots grade

Grade	Scale	Description
Clear	0 ~ 5	Clear skin with little to no spots
Almost Clear	6 ~ 15	Skin with mild pigmentation problem, sparse spots
Moderate	16 ~ 48	Moderate amount of spots covering portion of the skin
Poor	49 ~ 80	Severe skin pigmentation with large area of skin covered with spots
Severe	81 ~ 99	Very severe skin pigmentation with wide spread spots covering most part of skin

Table 3. Representative images of skin spots grade

Clear
Almost Clear
Moderate
Poor
Severe