что значит TLC в этом тексте: we developed TLC as a general representation to facilitate line processing?

в целом текст такой
Lines are often important entities for analyzing images. For some images, the information is inherently found as lines, as in text, handwriting, diagrams, and finger¬prints. For gray-scale images, lines are often a derived feature of interest as a result of such image-processing operations as edge detection or contour tracking. Because of the prevalence of lines across different applications, we developed TLC as a general representation to facilitate line processing and pattern recognition.