pycharmers.opencv.windows module

Define functions and classes to make OpenCV window easier to use.

This KEY table is created by the following programs.

>>> from pycharmers.utils import tabulate
>>> from pycharmers.opencv import *
>>> lst = []
>>> for DEFAULT_KEY_NAME in list(filter(lambda x:x.startswith("DEFAULT_") and x.endswith("_KEYS"), globals().keys())):
>>>     for group,(fmt,keys) in eval(DEFAULT_KEY_NAME).items():
>>>         for name, key in keys.items():
>>>             lst.append([DEFAULT_KEY_NAME, group, fmt.format(name=name), f"'{key}'"])
>>>             DEFAULT_KEY_NAME, group = ("", "")
>>> tabulate(lst, headers=["VARNAME", "group", "description ('name')", "key"], tablefmt="grid")

VARNAME	group	description (‘name’)	key
DEFAULT_CV_KEYS	BASE	To send the window the command ‘info’	‘i’
		To send the window the command ‘quit’	‘q’
		To send the window the command ‘delete’	‘<delete>’
		To send the window the command ‘enter’	‘<enter>’
	MOVING	To move the window to the ‘left’	‘h’
		To move the window to the ‘right’	‘l’
		To move the window to the ‘down’	‘j’
		To move the window to the ‘up’	‘k’
	RATIO	To ‘expansion’ the window	‘+’
		To ‘reduction’ the window	‘-‘
	POSITION	To set/know the window ‘fullscreen’	‘f’
		To set/know the window ‘topleft’	‘o’
		To set/know the window ‘rectangle’	‘r’
DEFAULT_FRAME_KEYS	FRAME	To ‘advance’ frame	‘w’
		To ‘back’ frame	‘b’
		To ‘jump’ frame	‘@’
	RANGE	To select range ‘start’	‘s’
		To select range ‘end’	‘e’
	TAKE	To take ‘picture’	‘p’
		To take ‘video’	‘v’
DEFAULT_REALTIME_KEYS	TAKE	To take ‘picture’	‘p’
		To take ‘video’	‘v’
DEFAULT_TRACKING_KEYS	TRACKING	To track ‘start’	‘t’
		To track ‘stop’	‘c’
		To track ‘init’	‘n’

pycharmers.opencv.windows.cv2key2chr(key)

Convert a key event into a Unicode string or an easy-to-understand string.

Parameters

key (int) – The key event. (return of cv2.waitKey )

Returns

a Unicode string of one character or an easy-to-understand string.

Return type

(str)

Examples

>>> from pycharmers.opencv import cv2key2chr
>>> import cv2
>>> import numpy as np
>>> from pycharmers.opencv import cv2key2chr
...
>>> winname = "cv2key2chr"
>>> image = np.random.randint(low=0, high=255, size=(200,200,3), dtype=np.uint8)
>>> while True:
...     key = cv2.waitKey(1)
...     cv2.imshow(winname=winname, mat=image)
...     if key!=-1: print(key, cv2key2chr(key))
...     if key==27: break
>>> cv2.destroyWindow(winname=winname)

class pycharmers.opencv.windows.cvKeys(**cv_keys)

Bases: object

Keys for using openCV

Parameters

cv_keys (dict) – Key information. See set_keys . {group: [fmt, {name1:key1, name2:key2,...}]}

info_table

List-style Information. This strings are used in method describe

Type

list

groups

Group list.

Type

list

GROUP_NAME_KEY

Key for a command.

Type

str

GROUP_NAME_KEY_ORD

Ord of the Key ( GROUP_NAME_KEY )

Type

int

GROUP_KEYS

Keys for a group commands.

Type

list

GROUP_KEYS_ORD

Ords of the all Keys in a group ( GROUP_KEYS )

Type

list

ALL_KEYS

All Keys for commands.

Type

list

ALL_KEYS_ORD

All ords of the all Keys (ALL_KEYS)

Type

list

Examples

>>> from pycharmers.opencv import cvKeys, DEFAULT_CV_KEYS
>>> cvKey = cvKeys(**DEFAULT_CV_KEYS)
>>> cvKey.MOVING_LEFT_KEY
'h'
>>> cvKey.MOVING_LEFT_KEY_ORD
104
>>> cvKey.MOVING_KEYS
['h', 'l', 'j', 'k']
>>> cvKey.MOVING_KEYS_ORD
[104, 108, 106, 107]
>>> cvKey.ALL_KEYS
['i', 'q', '<delete>', '<enter>', 'h', 'l', 'j', 'k', '+', '-', 'f', 'o']
>>> cvKey.ALL_KEYS_ORD
[105, 113, 8, 13, 104, 108, 106, 107, 43, 45, 102, 111]

update(other)

Update using other instance.

Parameters

other (cvKeys) – Instance of cvKeys

set_keys(group, fmt, **keys)

Set keys.

Parameters

• group (str) – A group name. (ex. "MOVING" )

• fmt (str) – How to describe group keys. Need to contain “{name}” (ex. "To move the window to the {name}" )

• keys (dict) – {name1:key1, name2:key2, ...} * name (str) : A name in the group . (ex. "left" ) * key (str) : A key corresponding to the name . (ex. "l")

describe()

Describe Key information.

static ord(c=None)

Return the Unicode code point for a one-character string.

Parameters

c (str) – A character

Returns

Unicode code point

Return type

i (int)

Examples

>>> from pycharmers.opencv import cvKeys
>>> cvKey = cvKeys()
>>> cvKey.ord("l") == ord("l")
True
>>> cvKey.ord("<delete>")
8
>>> ord("<delete>")
TypeError: ord() expected a character, but string of length 8 found

property ALL_KEYS

Return all the keys that have been set.

property BASE_KEYS

property FRAME_KEYS

property MOVING_KEYS

property POSITION_KEYS

property RANGE_KEYS

property RATIO_KEYS

property TAKE_KEYS

property TRACKING_KEYS

pycharmers.opencv.windows.wait_for_input(fmt='Your input : {val}', cvKey=<pycharmers.opencv.windows.cvKeys object>)

Wait until the valid input is entered.

Parameters

• fmt (str) – Format to show your current input value. ( "{val}" must be included.)

• cvKey (cvKeys) – Instance of cvKeys

Returns

Input string.

Return type

curt_val (str)

Examples

>>> import cv2
>>> from pycharmers.opencv import wait_for_input, SAMPLE_LENA_IMG
>>> cv2.imshow("Lena", cv2.imread(SAMPLE_LENA_IMG))
>>> val = wait_for_input()
>>> cv2.destroyAllWindows()

pycharmers.opencv.windows.wait_for_choice(*choices)

Wait until choicing the one of the keys.

Parameters

choices (tuple) – Choices.

Returns

The ith element in choices . ( i means Your input. )

Return type

choice (element)

Examples

>>> import cv2
>>> from pycharmers.opencv import wait_for_choice, SAMPLE_LENA_IMG
>>> cv2.imshow("Lena", cv2.imread(SAMPLE_LENA_IMG))
>>> val = wait_for_choice(*list("ltrb"))
>>> cv2.destroyAllWindows()

class pycharmers.opencv.windows.cvWindow(winname=None, dirname=None, move_distance=10, expansion_rate=1.1, cvKey=<pycharmers.opencv.windows.cvKeys object>)

Bases: object

Window & Image Location

• Ix,Iy,Iw,Ih = getWindowImageRect

• moveWindow make the window left top to (x,y)

Variable Names:

(Wx,Wy) ----------------------- (x+w,y)
    |               ^                |
    |               | Fh             |
    |               v                |
    |     (Ix,Iy) ------ (Ix+w,Iy)   |
    |   Fw   |               |       |
    |<------>|     Image     |       |
    |        |               |       |
    |    (Ix,Iy+h) ---- (Ix+w,Iy+h)  |
    |                                |
(Wx,Wy+h) --------------------- (Wx+w,Wy+h)

Parameters

no (int) – The number of windows.

video_save_dir

Path/to/created_video/directory

Type

str

img_save_dir

Path/to/created_image/directory

Type

str

reduction_rate

1./expansion_rate

Type

float

cvKey

Keys that can be used with OpenCV.

Type

cvKeys

Examples

>>> import cv2
>>> from pycharmers.opencv import cvWindow
>>> window = cvWindow()
>>> while True:
...     key = cv2.waitKey(0)
...     is_break = window.recieveKey(key)
...     if is_break:
...         break
>>> cv2.destroyAllWindows()

no = 0

property reduction_rate

setup(winname=None, dirname=None)

Setting up for the OpenCV windows.

• Decide window name.

• Decide and Create the location of the directory to save image.

Parameters

• winname (str) – Unique winname.

• dirname (str) – dirname for saved image or directory.

property frame_size

Get Frame width (Fw) and Frame height (Fh)

property image_size

Get Image width (Iw) and Image height (Ih)

resizeWindow(width, height)

Resizes window to the specified size

Parameters

• width (int) – The new window width.

• height (int) – The new window height.

moveWindow(x, y)

Moves window to the specified position

Parameters

• x (int) – The new x-coordinate of the window.

• y (int) – The new y-coordinate of the window.

getWindowImageRect()

Provides rectangle of image in the window.

The function getWindowImageRect returns the client screen coordinates, width and height of the image rendering area.

getWindowRect()

Get window bounding boxes as (x,y,w,h)

get_anchors()

Get the (Wx,Wy,Fw,Fh)

Notes

• getWindowImageRect gets the rectangle of image in the window.

• moveWindow make the window left top to (x,y)

show(mat)

Displays an image in the specified window. (self.winname)

Parameters

mat (np.ndarray) – Image to be shown.

describe()

Describe Key info.

destroy()

Do the necessary processing at the end.

recieveKey(key)

Response according to Recieved key.

Parameters

key (int) – Input Key. (= cv2.waitKey(0))

Returns

is_break (bool) Whether loop break or not. If break, destroy the window.

class pycharmers.opencv.windows.RealTimeWindow(winname=None, dirname=None, ext='.jpg', move_distance=10, expansion_rate=1.1, cam=0, cvKey=<pycharmers.opencv.windows.cvKeys object>)

Bases: pycharmers.opencv.windows.cvWindow

OpenCV window for RealiTime Video.

Parameters

• ext (str) – File extension. (default= ".jpg" )

• cam (int) – The id of the web camera.

basenames

Concatenate of the final components of path

Type

str

gen

cv2.VideoCapture(cam)

Type

gen

crt_frame

The current image.

Type

ndarray

crt_fname

The current image name.

Type

str

is_capture

Whether capturing or not.

Type

bool

Examples

>>> import cv2
>>> from pycharmers.opencv import RealTimeWindow
>>> window = RealTimeWindow()
>>> while True:
...     key = cv2.waitKey(0)
...     is_break = window.recieveKey(key)
...     if is_break:
...         break
>>> cv2.destroyAllWindows()

show(mat=None)

Displays an image in the specified window. (self.winname)

Parameters

mat (np.ndarray) – Image to be shown.

destroy()

Do the necessary processing at the end.

recieveKey(key)

Response according to Recieved key.

Parameters

key (int) – Input Key. (= cv2.waitKey(0))

Returns

is_break (bool) Whether loop break or not. If break, destroy the window.

class pycharmers.opencv.windows.FrameWindow(*path, winname=None, dirname=None, ext='.jpg', move_distance=10, expansion_rate=1.1, cvKey=<pycharmers.opencv.windows.cvKeys object>)

Bases: pycharmers.opencv.windows.cvWindow

OpenCV window for Frames (images or video).

Parameters

• path (str) – path to video file, or directory which stores sequential images.

• ext (str) – File extension. (default= ".jpg" )

basenames

Concatenate of the final components of path

Type

str

input_path

path

Type

tuple

frame_generator

function which generates sequential frames. - If len(path)==1 -> mono_frame_generator - Otherwise -> multi_frame_generator_concat

Type

function

gen

Generator created by frame_generator

Type

gen

total_num

The total number of frames.

Type

int

crt_frame_no

The current number of frames. (1-based index.)

Type

int

crt_frame

The current image.

Type

ndarray

range_start

Start number in the selected range.

Type

int

range_end

End number in the selected range.

Type

int

Examples

>>> import cv2
>>> from pycharmers.opencv import FrameWindow, SAMPLE_VTEST_VIDEO
>>> window = FrameWindow(SAMPLE_VTEST_VIDEO)
>>> while True:
...     key = cv2.waitKey(0)
...     is_break = window.recieveKey(key)
...     if is_break:
...         break
>>> cv2.destroyAllWindows()

fnaming(*no, ext=None)

Naming the file based on the number of frame.

Parameters

• no (int) – Index of the frame.

• ext (str) – File extension.

show(mat=None)

Displays an image in the specified window. (self.winname)

Parameters

mat (np.ndarray) – Image to be shown.

recieveKey(key)

Response according to Recieved key.

Parameters

key (int) – Input Key. (= cv2.waitKey(0))

Returns

is_break (bool) Whether loop break or not. If break, destroy the window.

range_processing()

Select a range and process the image or video of that part.

class pycharmers.opencv.windows.TrackingWindow(path, tracker='boosting', coord_type='xywh', bbox=(0, 0, 0, 0), winname=None, dirname=None, move_distance=10, expansion_rate=1.1, cvKey=<pycharmers.opencv.windows.cvKeys object>, **metadata)

Bases: pycharmers.opencv.windows.FrameWindow, pycharmers.opencv.windows.RealTimeWindow

OpenCV window for Trackings (images or video).

Examples

>>> import cv2
>>> from pycharmers.opencv import TrackingWindow, SAMPLE_VTEST_VIDEO
>>> window = TrackingWindow(path=SAMPLE_VTEST_VIDEO, tracker="boosting", coord_type="xywh")
>>> while True:
...     key = cv2.waitKey(0)
...     is_break = window.recieveKey(key)
...     if is_break:
...         break
>>> cv2.destroyAllWindows()

property init_bbox_winname

init(bbox=0, 0, 0, 0, coord_type='xywh', input_path=None, dirname=None, **metadata)

recieveKey(key)

Response according to Recieved key.

Parameters

key (int) – Input Key. (= cv2.waitKey(0))

Returns

is_break (bool) Whether loop break or not. If break, destroy the window.