1. Chuyn sang nh xm+ c file nh lu vo bin kiu Bitmap+ c d liu t Bitmap vo BitmapData s dng hm LockBits ca Bitmap.+ BitmapData c hai thuc tnh quan trng:

- Stride: kiu int: di tnh theo byte ca mt hng trong ma trn nh.- Scan0: con tr kiu int: Tr ti im nh u tin.- T Stride tnh ra offset ca mt hng: offset = Stride - Bitmap.Width * 3

+ Chuyn sang nh xm theo t l: R: G: B = 0.299 : 0.587 : 0.114+ B kha d liu: S dng hm UnlockBits ca Bitmap

6/4/2015o Th HngBi Th Thu HinNguyn Th HngNguyn Trng ThVi Vn Phong