| [ PhilosophyThought ] in KIDS 글 쓴 이(By): pinkrose (슈퍼따라지) 날 짜 (Date): 1999년 3월 22일 월요일 오후 12시 49분 51초 제 목(Title): neuron and machine vision. wow chopin's postings are very interesting to read. while reading about how neurons on eye balls react to the slope of lines, i was somewhat suprised. in machine vision, when a machine tried to detect edges, what programmers actually do is they break the lines into a couple of categories. Because in machine vision, the vision is pixellized into rectangular coordinates, the neighborhood realtion are (in 2D ) horizontal, vertical, 45 degree, 180+45 degree. (4 pixels are required for above classification. why? ) These forms a basis for space of edges. If we want to increase the resolution of the machine vision, we must increase the #of pixels for classification. There is very striking similarity between this method and what chopin said. So far I have only seen non-parellel algorithms. Chopin I think you missed the explanation for how actually recognize the lines! Assuming everything is in black and white, human eyes can still recognize the lines. But WHAT ARE LINES? It is just the boundary of 2 2D object. For instance a person recognize the boundaries of a book on the dest because a book is one 2D object and the desk is also the other 2D object. If the book and the desk has almost same texture and alsmot same color, human eyes have difficulty recognizing the boundary of 2 2D objects. (Assuming that there is not much shade or shadow) HENCE, the distinction of colors and the distinction of color difference in 2 2D object must be also included in detecting shapes. I may be wrong since I know nothing about neurons but I think, distinguishing the edges is not at the neuron perception level but it may be the level where multiple neurons involved in parellel process which nobody knows yet. HOW are you going to distinguish if distinguishing edges are at a single neuron level or it involves a collection of such single neurons! If it involves a collection of neurons than it is definitely a second process not the first perception level. This is my critism of chopin's interesting posting. ^^ 스스로 겸허한 마음으로 자 신을 낮춰 낮은 곳에 위치하고 당분간은 자신의 연못에 물을 채우기에 전념하라． 개구리토정비결에 나온말. |