QR level of fault tolerance

1. Concept: The fault tolerance level is QR refers QR code is blocked or broken and still allow identification of the more higher level of fault tolerance ability of anti-broken or blocked, the dot density will increase the level of fault tolerance is increased, the recognition rate will reduce.
2. To google the zxing library, for example, fault tolerance zxing in QR code is divided into four levels:

L（低）：容错率为7%
M（中）：容错率为15%
Q（较高）：容错率为25%
H（高）：容错率为30%

3. Explanation: If L was set his fault tolerance in the generation of two-dimensional code, the two-dimensional code generating means up to 7% broken or blocked after still identifiable, but more than 7% can not be identified. I.e., the greater the chance at the higher fault tolerance situation, after the two-dimensional code is broken out successfully identified.