Moblabpy Documentation¶

class PROPS¶

A class that contains all the configurations of the Moblabpy module

FPS: int = 15¶: The frame per second of the generated video.

BPS: int = 16¶: The number of color matrix in each frame. It can be set by set_BPS() .

ROW: int = 4¶: The number of row of color matrix in each frame. ROW must be equal to COL and they are defined by the square root of BPS .

COL: int = 4¶: Same as ROW .

INFO_BIT_SIZE: int = 50¶: The height and width of each color matrix. It is defined by ROW divides 200.

START_BIT: str = "0"¶: The string representation of start bit and end bit of the video.

END_BIT: str = "0"¶: Same as START_BIT .

VID_SOURCE: str = "./16bps.mp4"¶: The video name of the generated video. It will be set by set_BPS() automatically if py:attr:BPS is modified.

SCALE: int = 2¶: The scale of the window size of the video player embedded in the MobLabPy .

set_BPS(bps)¶

Set the BPS of the video. It will also change the value of ROW, COL, INFO_BIT_SIZE and VID_SOURCE automatically.

Parameters: bps (int) – The BPS of the video

class MobLabPy¶

A class that allows users to connect their ip camera with the program to simulate a telecommunication system. It use the python multiprocessing modules to reduce the time delay of decoding images and capturing images. The program uses multiprocessing.Pipe object to send images between the send_frame() and recv_frame() .

__init__(self, ip_address, bit_mess, props=PROPS)¶

Initialize the member variable of the MobLabPy object.

Parameters

ip_address (str) – The ip address of the IP camera
bit_mess (str) – The transmitted bit sequence
props – A PROPS class

start(self)¶: Start getting frames from the ip camera and send it to the decoding function.

get_bit_seq(self)¶

Return the bit sequence of the :py:class`MobLabPy` object.

Returns bit_seq: The received bit sequence
Return type: list(char)

img_to_bit_seq(frame, pt1=(), pt2=(), props=PROPS)¶

Convert black and white color to “0” and “1” respectively.

Parameters

frame (numpy.ndarray) – Image.
pt1 (tuple(int, int)) – Vertex of the area bounded by qr codes, defaults to ()
pt2 (tuple(int, int)) – Vertex of the area bounded by qr codes opposite to pt1, defaults to ()
props (PROPS) – The PROPS object that contains the configurations of the program

Returns bit_seq, pt1, pt2

Decoded bit sequence and vertices of the area bounded by qr codes in opposite direction.

Return type

tuple(str, tuple(int, int), tuple(int, int))

Raises

IndexError – If it fails to calculate the mean of the RGB of the color matrix

check_orientation(frame, pt1, pt2)¶

Check the orientation of the image according to the qr codes in the corner.

Parameters

frame (numpy.ndarray) – Image
pt1 (tuple(int, int)) – Vertex of the area bounded by qr codes.
pt2 (tuple(int, int)) – Vertex of the area bounded by qr codes opposite to pt1.

Return result

Number of rotation needed to be performed

Return type

int

Raises

IndexError – If it fails to locate the qr codes

point_rotation(pt1, pt2, width, rotation)¶

Perform the rotation of vertices of the color matrix area.

Parameters

pt1 (tuple(int, int)) – Vertex of the color matrix
pt2 (tuple(int, int)) – Vertex of the color matrix opposite to pt1
width – Width of the image that contains the color matrix
rotation (int) – Number of rotation that needed to be performed

Type

int

Returns pt1, pt2

Vertices of the color matrix area after rotation

Type

tuple(tuple(int, int), tuple(int, int))

find_corner(frame, pt1=(), pt2=())¶

Find the vertex of the color matrix surrounded by but exclude qr codes.

Parameters

frame (numpy.ndarray) – Image
pt1 (tuple(int, int)) – Vertex of the area include qr codes, defaults to ()

Prarm pt2

Vertex of the area include qr codes opposite to pt1, defaults to ()

Returns size, pt1, pt2

size of the color matrix area and its vertices in opposite direction

Return type

tuple(int, tuple(int, int), tuple(int, int))

find_min_and_max(points, min_pt, max_pt)¶

Find the minimum and maximum xy-points in a list and the provides points.

Parameters

points (list(int)) – A list of points
min_pt (list(int)) – The minimum points provided
max_pt (list(int)) – The maximum points provided

Returns min_pt, max_pt

The minimum and maximum xy-points

Return type

tuple(intuple(int, int)t, tuple(int, int))

all_zeros_or_ones(bit_seq)¶

Check if the bit sequence contains only 0 or 1.

Parameters: bit_seq (str) – The bit sequence needed to be checked
Returns: “True” if the bit sequence only contains 0 or 1, “False” otherwise
Return type: bool
Raises: ValueError – it input contains non numerical values

str_to_ascii_seq(my_str='Apple')¶

Convert each character in a string to its corresponding ascii code.

Parameters: my_str (str) – The string wanted to be converted, defaults to Apple
Return ascii_arr: A list of integer that contains all the ascii code of each character in my_str
Return type: list(int)

ascii_seq_to_bit_seq(ascii_arr)¶

Convert a list of ascii code to its binary representation.

Parameters: ascii_arr (list(int)) – A list that contains ascii code
Return bit_arr: An integer binary list
Return type: list(int)

bit_seq_to_ascii_seq(bit_arr)¶

Perform byte conversion of an array.

Parameters: bit_arr (list(int)) – An integer binary array
Return ascii_arr: A list contains all the corresponding ascii code
Return type: list(int)

ascii_seq_to_str(ascii_arr)¶

Convert a list of ascii code to its corresponding character.

Parameters: ascii_arr (list(int)) – A list that contains ascii code
Return my_str: The character format of the ascii list
Return type: str

append_zeros(bit_seq, props=PROPS, is_str=False)¶

Append zeros until the length of the input equals to the products of desired length.

Parameters

bit_seq (list(int)) – Integer binary array
props (PROPS) – PROPS object that contains the configurations of the program.

Return bit_arr

An integer binary array which length is the product of the second parameter

Return type

list(int)

generate_img(dir_name, my_str='Hello World', if_bin=False, props=PROPS)¶

Generate images that contain color matrix of my_str parameter, with black represents 0 and white represents 1, and paste them with the qr codes (finder patterns) together. The generated images will be saved at the dir_name directory.

Parameters

dir_name (str) – The directory name used to save the image generated
my_str (str, list(int)) – The integer binary array or string which will be convert to color code formats, defaults to “Hello World”
if_bin (bool) – True if my_str is an integer binary array, False otherwise, defaults to False
props (PROPS) – the PROPS object that contains the properties of the program

generate_res()¶: Generate the res folder which contains all the head and end messages, start and end signals and finder patterns.

generate_video(video_name='16bps.mp4', mystr='Hello World', if_bin=False, props=PROPS)¶

Generate a video which contains start and end messages, start and end signals, finder patterns and color matrix of the mystr parameter, with desired fps.

Parameters

video_name (str) – The name of the generated video in mp4 format
mystr (str, list(int)) – The message that will be converted to color code, defaults to “Hello World”
if_bin (bool) – True if mystr is an integer binary array, False otherwise, defaults to False
props (PROPS) – the PROPS object that contains the properties of the program

recv_frame(fps, is_pilot_bit_found, recver, bit_seq, flag, bit_mess, props=PROPS)¶

Funtion that received frames from the sender function. It does all the manipulation of the captured iamge here, such as detecting start and end signals, checking rotations and decoding color codes back to 0 and 1.

Parameters

fps (multiprocessing.Value) – A multiprocessing.Value object which represents the fps of the camera
is_pilot_bit_found (multiprocessing.Value) – A multiprocessing.Value object which is True if the start signal is detected, False otherwise
recver (multiprocessing.Pipe) – A multiprocessing.Pipe object that received images sent from the sender function
bit_seq (multiprocessing.Value) – A multiprocessing.Value object whcih is the decoded bit sequence of received images
flag (multiprocessing.Value) – A multiprocessing.Value object which is the state of the play video button
bit_mess (str) – The transmitted bit sequence
props (PROPS) – The PROPS object that contains the properties of the program

vid_player(vid_source, flag, props=PROPS)¶

A video player will be appeared if the play video button is clicked

Parameters

vid_source (str) – The name of the video to pe played
flag (multiprocessing.Value) – A multiprocessing.Value object which is the state of the play video button
props (PROPS) – The PROPS object that contains the properties of the program

send_frame(fps, is_pilot_bit_found, sender, ip_address, props=PROPS)¶

A sender function which gets images from the connected camera and send it to the receiver function.

Parameters

fps (multiprocessing.Value) – A multiprocessing.Value object which represents the fps of the camera
is_pilot_bit_found (multiprocessing.Value) – A multiprocessing.Value object which is True if the start signal is detected, False otherwise
sender (multiprocessing.Pipe) – A multiprocessing.Pipe object that send images captured by the connected camera
ip_address (str) – IP address of the camera that is going to be connected
props (PROPS) – The :py:class:PROPS object that contains the properties of the program

encode(D, G)¶

Perform matrix multiplication on parameter D and G, which is D x G.

Parameters

D (list(int)) – A 1 x k matrix
G (numpy.ndarray) – A generator matrix

Return C

A 1 x n matrix

Return type

numpy.ndarray

Raises

ValueError – If the number of columns in the first matrix not equals to the number of rows in the second matrix
UFuncTypeError – If both parameters are not integer numpy.ndarray

syndrome(R, H)¶

Calculate the syndrome of the received bit sequence.

Parameters

R (list(int)) – A 1 x n matrix
H (numpy.ndarray) – A parity check matrix

class monitor¶

__init__(self, master, bit_mess)¶

Defines the monitor window.

Parameters

master (Tk) – Root window
bit_mess (str) – The bit sequence to be sent

update_recv(self, bit_seq)¶

Update the received and error bits textbox upon call.

Parameters: bit_seq – The bits that are collected from the receiver

button_toggle(self)¶: Switch the status of the button to True, which indicates it has been pressed.

get_button_status(self)¶

Return the status of the button.

Returns: The status of the button, whether it has been pressed
Return type: bool

close_windows(self)¶: Destroy the root window.

class VidCap¶

__init__(self, scale, vidsource=0)¶

Defines the video to be played and its porperty.

Parameters

scale (int) – The scale of which the video is being played. The higher the number, the bigger the video
vidsource (str) – The file path of the video

get_fps(self)¶

Return the fps of the video.

Returns: The fps of the video
Return type: int

get_height(self)¶

Return the height of the video.

Returns: The height of the video
Return type: int

get_width(self)¶

Return the width of the video.

Returns: The width of the video
Return type: int

get_frame(self)¶

Get one frame from the video.

Returns ret, frame: whether a frame is successfully grabbed; the image from the video, None otherwise.
Return type: tuple(bool, numpy.ndarray)

reset(self, vidsource=0)¶: Reset the video source and start from the beginning.

__del__(self)¶: Release the video when the window is closed.

class player¶

__init__(self, master, scale, vidsource=0)¶

Defines the video player window.

Parameters

master (Tk) – Root window
scale (int) – The scale of which the video is being played. The higher the number, the bigger the video
vidsource (str) – The file path of the video

update(self)¶: Update the video canvas to display the next frame.

restart_vid(self)¶: Replay the video.

close_windows(self)¶: Destroy the root window.