opencv-proto documentation¶

https://github.com/idlesign/opencv-proto

Description¶

Allows fast prototyping in Python for OpenCV

Offers primitives and simplified interfaces to streamline prototypes construction in Python.

Facilitates:

Windows construction and management
Trackbar construction
Configuration save/load (including trackbar values)
Key binding (e.g. for trackbar control, configuration save/load)
Video capturing and modification
Work with images
Work with text
Frames transformation

Requirements¶

Python 3.6+
opencv-python (or variants)

Quick install with third-parties: $ pip install opencv-proto[all]

Table of Contents¶

Quickstart¶

Color Palette¶

Let’s replace 37 lines of source code from Trackbar as the Color Palette tutorial with ocvproto-based implementation:

from ocvproto.toolbox import WindowManager, Canvas

with WindowManager() as wm:
    # Window manager will create a default window for us if none provided.
    # Default window is available through .window property.

    # With the help of .add_trackbar_group() we create three trackbars,
    # to adjust our color values for R, G and B. Batch apply `max` value
    # to all three trackbars.
    rgb = wm.window.add_trackbar_group(['R', 'G', 'B'], max=255)

    # If one doesn't configure their own Application object,
    # Window manager will instantiate one automatically, using default settings.
    for _ in wm.app.loop():
        # Most of the time we'll need a loop to process our frames.
        # Application object (available through .app property) offers us such a loop.

        # Lastly we create a canvas object using RGB value from trackbars,
        # and pass its' frame to .set_frame() shortcut.
        # That shortcut puts the frame into default window.
        wm.set_frame(Canvas(512, 300, color=rgb))

Camera capture¶

Now let’s capture video camera stream into ocvproto.avi file, being able to adjust blur.

Let’s also setup config filepath (ocvproto.json) - this allows us to store current trackbar values (s key) and load them (r key). It is useful to restore settings between sessions.

We bind z key to take camera shots.

from ocvproto.toolbox import WindowManager, Camera

with WindowManager() as wm:

    # We instruct our application to store settings into file.
    wm.app.set_config('ocvproto.json')

    # We create two trackbars to adjust blur.
    blur = wm.window.add_trackbar_group(['x', 'y'], 'Blur', default=1)

    # We initiate default (first available) camera connection.
    with Camera() as cam:

        # Let's add trackbars for adjustable camera properties (contrast, brightness, etc.).
        wm.window.add_trackbar_group(cam.describe_properties(), default=1, max=255)

        # You can bind keys to actions.
        # Here we bind `z` to trigger .cam.dump_image() to take stills.
        wm.app.bind_key('z', cam.dump_image)

        for _ in wm.app.loop():
            # Read a frame from camera, we'll work with.
            cam.read()

            # Now we blur that frame.
            cam.blur(blur)

            # And we dump the frame into the file.
            # If dumping parameters were not set up before
            # .dump() shortcut will use defaults
            # (e.g. `ocvproto.avi` name, XVID codec).
            cam.dump()

            # Show the frame.
            wm.set_frame(cam)

API¶

Application¶

class ocvproto.app.application.Application(*, config: Union[str, pathlib.Path, None] = None)¶

Represents ocvproto application.

Parameters:	config – Configuration to be used.

bind_key(key: Union[str, int], func: Callable)¶

Binds a key to a function.

Parameters:	key – func –

config_load()¶: Loads a configuration from config file.

config_save()¶: Saves current configuration to config file.

hook_register(key: str, func: Callable)¶

Registers a hook.

Parameters:	key – Hooks group key. func – Hook function to add to group.

loop()¶: Main application loop. Handles keys listening and issues a loop function (see .set_loop_func()).

set_config(config: Union[str, pathlib.Path, None], keys: Tuple[Union[str, int], Union[str, int]] = None)¶

Sets configuration from the app.

Parameters:	config – Configuration object. keys – Keys tuple to save and load configuration.

set_loop_func(func: Callable)¶: Sets a function to perform in a main app loop.

Config¶

class ocvproto.app.config.Config(fpath: Union[str, pathlib.Path, None])¶

Represent an interface to configuration file.

Parameters:	fpath – Configuration file path.

get_data(key: str, default: Any = None)¶

Reads data from a config section denoted by key.

Parameters:	key – default – Default values to return.

load()¶: Loads configuration from file.

save()¶: Saves configuration to file.

set_data(key: str, value: Any)¶

Places the data into config section denoted by key.

Parameters:	key – value –

Keys¶

class ocvproto.app.keys.Key¶: Keys registry. Can be used for binding actions.

User Interface¶

Windows Manager¶

class ocvproto.ui.wm.WindowManager(windows: List[ocvproto.ui.window.Window] = None, app: ocvproto.app.application.Application = None)¶

Manages windows.

Parameters:	windows – Windows to manage. If not set, one window is automatically constructed. app – ocvproto application object. Automatically constructed if not set.

config_load(config: ocvproto.app.config.Config)¶

Updates managed windows using data from the given config.

Parameters:	config –

config_update(config: ocvproto.app.config.Config)¶

Updates data gathered from managed windows in the given config.

Parameters:	config –

iter_trackbars() → Generator[Tuple[ocvproto.ui.window.Window, ocvproto.ui.trackbars.base.Trackbar], None, None]¶: Generator yielding managed windows and trackbars.

render()¶: Renders managed windows.

set_frame(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame])¶

Sets frame to be rendered in default window.

Parameters:	frame –

window¶: Default window.

Window¶

class ocvproto.ui.window.Window(name: str = None)¶

Represents a window.

Parameters:	name – Window name. If not set, automatically generated.

add_trackbar(*trackbars)¶

Add the given trackbars to the window.

Parameters:	trackbars –

add_trackbar_group(definitions: Union[int, Dict[str, dict], List[dict], List[str]], prefix: str = '', **common_kwargs) → Tuple¶

A shortcut to batch create trackbars in a declarative way.

Parameters:

definitions –
Definitions to construct trackbars.
- Integer:
  - 2 - create two trackbars with generated titles and default params.
- List:
  - [‘one’, ‘two’, ‘three’] -
    
    create 3 trackbars with the given titles and default params.
  - [{‘keys’: ‘kl’}, {}] -
    
    create 2 trackbars with generated titles and default params.
- Dictionary:
  - {‘y’: {‘keys’: ‘kl’}, ‘x’: {‘step’: 20}} - create 2 trackbars with the given titles and params.
prefix – Prefix to add to trackbars titles.
common_kwargs – Common keyword arguments to pass to all trackbars.

create(*, autosize=True)¶

Creates a window.

Parameters:	autosize – If try, window is automatically sized to a content.

position(*, x: int, y: int)¶: Positions the window.

render()¶: Renders window contents.

resize(*, width: int, height: int)¶

Resizes the window.

Parameters:	width – height –

set_frame(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame])¶

Sets current frame for the window.

Parameters:	frame –

Trackbar¶

class ocvproto.ui.trackbars.base.Trackbar(name, *, max: Union[int, float] = None, default: Union[int, float] = None, callback: Callable = None, step: Union[int, float] = None, keys: str = None)¶

Represents a trackbar.

Parameters:	name – Name to show in UI and address this in opencv api. max – Max value. Default: 100 default – Default (current) value. Default: 0 callback – Function to be called on trackbar value change through UI. step – Step to inc/dec trackbar value. Default: 1 keys – Two-letter string to represent keys to inc and dec value.

bind(window_name: str)¶

Binds the trackabr to the given window.

Parameters:	window_name –

dec()¶: Decrements the current value.

get_value() → Union[int, float]¶: Force getting current value.

inc()¶: Increments the current value.

onChange(val: Union[int, float])¶: Issued on value change from UI.

value¶: Current trackbar value.

Sources¶

Image¶

class ocvproto.sources.image.Image(src: Union[int, str, <sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame] = None)¶

Bases: ocvproto.sources.base.Source

Represents an image.

Parameters:	src – Source id (int), path (str) or frame (np array)

absdiff(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame]) → ocvproto.frame.Frame¶

Returns absolute difference between the current and a given frame as a new Source.

Parameters:	frame –

blur(ksize: Tuple[int, int]) → ocvproto.frame.Frame¶

Blures the current frame inplace.

Parameters:	ksize – Kernel size tuple (width, height)

canny(thr_1: int, thr_2: int) → ocvproto.frame.Frame¶

Applies Canny Edge Detection algorithm to the current frame inplace.

Parameters:	thr_1 – thr_2 –

dilate(element: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame], iterations: int = None) → ocvproto.frame.Frame¶

Dilates the current frame inplace.

Parameters:	element – iterations –

draw_rectangle(*, pos: Tuple[int, int], width: int, height: int, color: Union[int, str, Tuple[int, int, int]] = None)¶

Draws a rectangle.

Parameters:	pos – Top left corner (x, y). width – height – color –

dump(fpath: Union[str, pathlib.Path] = None)¶

Dumps frame into a file.

Parameters:	fpath – Filepath to store image into. If not set, name is generated automatically.

fill(color: Union[int, str, Tuple[int, int, int]])¶

Fills the canvas with the given color.

Parameters:	color –

frame¶: Current frame.

height¶: Height

make_gray() → ocvproto.frame.Frame¶: Makes the current frame grayscale inplace.

make_rgb() → ocvproto.frame.Frame¶: Makes the current frame RGB inplace.

read() → ocvproto.sources.image.Image¶: Read and return current frame.

resize(width: int, height: int) → ocvproto.frame.Frame¶

Resizes the current frame inplace.

Parameters:	width – height –

width¶: Width

Camera¶

class ocvproto.sources.camera.Camera(src: Union[int, str] = 0)¶

Bases: ocvproto.sources.video.Video

Represents a camera device.

Parameters:

src –

Device path (str) or id (int). Default 0.

E.g.:

’/dev/video0’
0
1

absdiff(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame]) → ocvproto.frame.Frame¶

Returns absolute difference between the current and a given frame as a new Source.

Parameters:	frame –

blur(ksize: Tuple[int, int]) → ocvproto.frame.Frame¶

Blures the current frame inplace.

Parameters:	ksize – Kernel size tuple (width, height)

brightness¶: Brightness

canny(thr_1: int, thr_2: int) → ocvproto.frame.Frame¶

Applies Canny Edge Detection algorithm to the current frame inplace.

Parameters:	thr_1 – thr_2 –

codec¶: FOURCC codec alias.

contrast¶: Contrast

describe_properties() → Dict[str, Any]¶

Returns descriptions for CV properties found in the class of this object and its bases.

One can initialize trackbars with these descriptions: see Window.add_trackbar_group()

dilate(element: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame], iterations: int = None) → ocvproto.frame.Frame¶

Dilates the current frame inplace.

Parameters:	element – iterations –

draw_rectangle(*, pos: Tuple[int, int], width: int, height: int, color: Union[int, str, Tuple[int, int, int]] = None)¶

Draws a rectangle.

Parameters:	pos – Top left corner (x, y). width – height – color –

dump(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame] = None)¶: Writes the current or the given frame. Automatically configures writer object is needed.

dump_image(fpath: Union[str, pathlib.Path] = None)¶

Dumps the image into a file.

Parameters:	fpath – Filepath to store image into. If not set, name is generated automatically.

dump_setup(fpath: Union[str, pathlib.Path] = 'ocvproto.avi', *, width: int = None, height: int = None, fps: Union[int, float] = None, codec: str = 'XVID') → <sphinx.ext.autodoc.importer._MockObject object at 0x7f080323b2e8>¶

Configures write parameters. Returns opencv writer object.

Parameters:	fpath – Filepath. width – height – fps – Frames per second. codec – FOURCC codec alias.

exposure¶: Exposure

fill(color: Union[int, str, Tuple[int, int, int]])¶

Fills the canvas with the given color.

Parameters:	color –

frame¶: Current frame.

gain¶: Gain

get_image() → ocvproto.sources.image.Image¶: Returns image object from the current frame.

hue¶: Hue

make_gray() → ocvproto.frame.Frame¶: Makes the current frame grayscale inplace.

make_rgb() → ocvproto.frame.Frame¶: Makes the current frame RGB inplace.

read() → ocvproto.sources.video.Video¶: Read and return current frame.

resize(width: int, height: int) → ocvproto.frame.Frame¶

Resizes the current frame inplace.

Parameters:	width – height –

saturation¶: Saturation

set_property(name: str, value: int)¶

Helper method to set property value.

Parameters:	name – Property name. value –

Video¶

class ocvproto.sources.video.Property(cv_prop: int, *, max: int = None)¶

Bases: object

Represents a capture video property with restrictions.

class ocvproto.sources.video.Video(src: Union[str, <sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>])¶

Bases: ocvproto.sources.base.Source

Represents a video.

absdiff(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame]) → ocvproto.frame.Frame¶

Returns absolute difference between the current and a given frame as a new Source.

Parameters:	frame –

blur(ksize: Tuple[int, int]) → ocvproto.frame.Frame¶

Blures the current frame inplace.

Parameters:	ksize – Kernel size tuple (width, height)

canny(thr_1: int, thr_2: int) → ocvproto.frame.Frame¶

Applies Canny Edge Detection algorithm to the current frame inplace.

Parameters:	thr_1 – thr_2 –

codec¶: FOURCC codec alias.

describe_properties() → Dict[str, Any]¶

Returns descriptions for CV properties found in the class of this object and its bases.

One can initialize trackbars with these descriptions: see Window.add_trackbar_group()

dilate(element: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame], iterations: int = None) → ocvproto.frame.Frame¶

Dilates the current frame inplace.

Parameters:	element – iterations –

draw_rectangle(*, pos: Tuple[int, int], width: int, height: int, color: Union[int, str, Tuple[int, int, int]] = None)¶

Draws a rectangle.

Parameters:	pos – Top left corner (x, y). width – height – color –

dump(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame] = None)¶: Writes the current or the given frame. Automatically configures writer object is needed.

dump_image(fpath: Union[str, pathlib.Path] = None)¶

Dumps the image into a file.

Parameters:	fpath – Filepath to store image into. If not set, name is generated automatically.

dump_setup(fpath: Union[str, pathlib.Path] = 'ocvproto.avi', *, width: int = None, height: int = None, fps: Union[int, float] = None, codec: str = 'XVID') → <sphinx.ext.autodoc.importer._MockObject object at 0x7f080323b2e8>¶

Configures write parameters. Returns opencv writer object.

Parameters:	fpath – Filepath. width – height – fps – Frames per second. codec – FOURCC codec alias.

fill(color: Union[int, str, Tuple[int, int, int]])¶

Fills the canvas with the given color.

Parameters:	color –

focus¶: Focus

fps¶: FPS

frame¶: Current frame.

gamma¶: Gamma

get_image() → ocvproto.sources.image.Image¶: Returns image object from the current frame.

height¶: Height

make_gray() → ocvproto.frame.Frame¶: Makes the current frame grayscale inplace.

make_rgb() → ocvproto.frame.Frame¶: Makes the current frame RGB inplace.

read() → ocvproto.sources.video.Video¶: Read and return current frame.

resize(width: int, height: int) → ocvproto.frame.Frame¶

Resizes the current frame inplace.

Parameters:	width – height –

set_property(name: str, value: int)¶

Helper method to set property value.

Parameters:	name – Property name. value –

sharpness¶: Sharpness

width¶: Width

zoom¶: Zoom

Miscellaneous¶

Canvas¶

class ocvproto.misc.canvas.Canvas(width: int = 640, height: int = 480, *, channels: int = 3, color: Union[int, str, Tuple[int, int, int]] = None)¶

Represents a canvas.

Parameters:	width – height – channels – color –

absdiff(frame: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame]) → ocvproto.frame.Frame¶

Returns absolute difference between the current and a given frame as a new Source.

Parameters:	frame –

blur(ksize: Tuple[int, int]) → ocvproto.frame.Frame¶

Blures the current frame inplace.

Parameters:	ksize – Kernel size tuple (width, height)

canny(thr_1: int, thr_2: int) → ocvproto.frame.Frame¶

Applies Canny Edge Detection algorithm to the current frame inplace.

Parameters:	thr_1 – thr_2 –

dilate(element: Union[<sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, Frame], iterations: int = None) → ocvproto.frame.Frame¶

Dilates the current frame inplace.

Parameters:	element – iterations –

draw_rectangle(*, pos: Tuple[int, int], width: int, height: int, color: Union[int, str, Tuple[int, int, int]] = None)¶

Draws a rectangle.

Parameters:	pos – Top left corner (x, y). width – height – color –

dump(fpath: Union[str, pathlib.Path] = None)¶

Dumps frame into a file.

Parameters:	fpath – Filepath to store image into. If not set, name is generated automatically.

fill(color: Union[int, str, Tuple[int, int, int]])¶

Fills the canvas with the given color.

Parameters:	color –

height¶: Height

make_gray() → ocvproto.frame.Frame¶: Makes the current frame grayscale inplace.

make_rgb() → ocvproto.frame.Frame¶: Makes the current frame RGB inplace.

resize(width: int, height: int) → ocvproto.frame.Frame¶

Resizes the current frame inplace.

Parameters:	width – height –

width¶: Width

Colors¶

ocvproto.misc.colors.COLORS = {'beige': (245, 245, 220), 'black': (0, 0, 0), 'blue': (0, 0, 255), 'brown': (165, 42, 42), 'chocolate': (210, 105, 30), 'cyan': (0, 255, 255), 'gold': (255, 215, 0), 'gray': (128, 128, 128), 'green': (0, 128, 0), 'indigo': (75, 0, 130), 'khaki': (240, 230, 140), 'lime': (0, 255, 0), 'linen': (250, 240, 230), 'magenta': (255, 0, 255), 'maroon': (128, 0, 0), 'navy': (0, 0, 128), 'olive': (128, 128, 0), 'orange': (255, 165, 0), 'pink': (255, 192, 203), 'purple': (128, 0, 128), 'red': (255, 0, 0), 'silver': (192, 192, 192), 'tan': (210, 180, 140), 'teal': (0, 128, 128), 'violet': (238, 130, 238), 'wheat': (245, 222, 179), 'white': (255, 255, 255), 'yellow': (255, 255, 0)}¶: Color aliases to RGB tuples map.

ocvproto.misc.colors.to_rgb(value: Union[int, str, Tuple[int, int, int]]) → Tuple[int, int, int]¶

Translates the given color value to RGB tuple.

Parameters:	value –

Text¶

class ocvproto.misc.text.Text(val: str = None, *, face: str = None, scale: float = None, color: Union[int, str, Tuple[int, int, int]] = None, pos: Tuple[int, int] = None, weight: int = None)¶

Represents a text that can be placed into a frame.

Parameters:	val – Text value itself. face – Font face alias (see .face_map keys). Default: normal scale – Scale factor. Default: 1 color – Color RGB tuple or alias (see COLORS). Default: white pos – Position tuple (x, y) in frame from top-left. Default: (20, 20) weight – Line thickness. Default: 1

put_on(frame, text: str = None, *, pos: Tuple[int, int] = None)¶

Applies text to the frame.

Parameters:	frame – Frame to apply text to. text – Text value to set on frame. If not set, value from initializer is used. pos – Position tuple (x, y) in frame from top-left. Default: (20, 20)

classmethod put_on_demo(frame: <sphinx.ext.autodoc.importer._MockObject object at 0x7f08033a7be0>, text: str = 'Test Text 1 2 3 4 5')¶

Demonstrates available font faces applying all of them to the frame.

Parameters:	frame – Frame to apply text to. text – Text value to on frame.

Primitives¶

Legend¶

class ocvproto.primitives.legend.Legend(labels: Sequence[str], pos: Tuple[int, int] = None, width: int = None, gap: int = None)¶

Bases: object

Represents a color-legend for labels.

Parameters:	labels – Strings to get colors for. pos – Position (x, y) to place top left legend corner. Default: (20, 20) width – Default: 250 gap – Base gap (also a height for each color stripe). Default: 25

put_on(frame: ocvproto.frame.Frame, *, pos: Tuple[int, int] = None)¶

Applies the legend to the frame.

Parameters:	frame – Frame to apply the legend to. pos – Position (x, y) to place top left legend corner. Default: (20, 20)