y = (256x -369)/625
625Y = 256X - 369
X = (625Y + 369)/256 = 2Y + 1 + (113Y + 113)/256 = 2Y + 1 + 113(Y + 1)/256
显然Y最小 = 255,X最小 = 624
y = (256x -369)/625
625Y = 256X - 369
X = (625Y + 369)/256 = 2Y + 1 + (113Y + 113)/256 = 2Y + 1 + 113(Y + 1)/256
显然Y最小 = 255,X最小 = 624