collagen shrinkage， collagen fibers shrinking

feature recoginition and recognition

recognition of gray scale Optical Character Recognition

sources recognition or reconstruction

Ⅰ collagen

Ⅰ Collagen cross linked c-telopeptide ICTP

Ⅰ Collagen cross linked c-telopeptide(ICTP)

Ⅰ type collagen

Ⅰcollagen

Ⅰtype collagen

Ⅱtype collagen

Ⅲ collagen

Ⅲ type collagen

Ⅳ collagen

Ⅳ type collagen

Ⅳcollagen

Ⅳ-collagen

absorbable collagen membrane

acellular collagen matrix