Week 7 : String and photo processing

Today’s Tasks  Practice list and string  Convert Decimal to any radix base number  Between Binary and Hexadecimal  Practice more photo processing  Skewing  Caution: Delete your script files (*.py) before shutting down your PC!

Number Conversion (1/3)  How to convert?  Use quotient & remainder  Divide the quotient by the radix base number until the quotient is 0  Write remainders in reverse order  As a result, octal equivalent of decimal number 140 is 214

Number Conversion (2/3)  Define a conversion function  User Inputs  Number - positive integer  Radix - between 2 and 16  Output  Just digits, no gap or another character  123 (O) ‘1’ ‘2’ ‘3’ (x)  “Wrong input!!!” if inputs are not in range  You must use the formatting operator % (TAs will check!!!)  You should implement 2 programs  1. Use a list variable (e.g. converted_number=[])  Print a list to a string  use join()  2. Use a string variable (e.g. converted_number =“”) def deci_to_any(n, radix) :

Number Conversion (3/3) >>> [evaluate dec_to_any.py] Enter a number: 10 Enter a radix: 2 10 in base 10 is 1010 in base 2 >>> [evaluate dec_to_any.py] Enter a number: 61 Enter a radix: in base 10 is 3D in base 16 >>> [evaluate dec_to_any.py] Enter a number: 5 Enter a radix: 17 Wrong Input!!! >>> [evaluate dec_to_any.py] Enter a number: -5 Wrong Input!!!

Skewing (1/2)  Create the image skewed on an angle from the vertical or horizontal Input img Direction Angle Output Vertical -30 Horizontal -30 Horizontal 30 Vertical 30

Skewing (2/2)  Define a skewing function  User Inputs  Direction – vertical or horizontal  Angle – between -89 and 89  Output  Create a new skewed image  “Wrong input!!!” if inputs are not in range  You can use math functions or built-in functions  pi, sin, cos, tan, radians, …  abs  Type conversion def skew(img, …) : 30° ?

Any Questions?