https://github.com/alkasm/cvpack

Utilities for OpenCV in Python
https://github.com/alkasm/cvpack

computer-vision image-processing opencv python

Last synced: about 1 month ago
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Utilities for OpenCV in Python

• Host: GitHub
• URL: https://github.com/alkasm/cvpack
• Owner: alkasm
• License: mit
• Created: 2018-09-22T08:53:47.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2021-04-21T08:49:01.000Z (over 3 years ago)
• Last Synced: 2024-09-29T00:21:45.083Z (about 2 months ago)
• Topics: computer-vision, image-processing, opencv, python
• Language: Python
• Size: 362 KB
• Stars: 14
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# cvpack

OpenCV extensions for more Pythonic interactions.

## Install

    

```sh

pip install cvpack-alkasm

```

## Types

`cvpack` includes types that exist in the main C++ OpenCV codebase, but that aren't included in the Python bindings. They are compatible as arguments to OpenCV functions, and they implement the same interfaces (with some new additions). The types that are included are `Point`, `Point3`, `Rect`, `RotatedRect`, `Size`, `TermCriteria`. They are implemented as namedtuples, and as such are immutable.

```python

import cvpack

img = cvpack.imread("img.png")

p1 = cvpack.Point(50, 50)

p2 = cvpack.Point(100, 100)

rect = cvpack.Rect.from_points(p1, p2)

roi = img[rect.slice()]

roi_size = cvpack.Size.from_image(roi)

assert roi_size == rect.size()

```

The overloaded constructors are available as `from_` classmethods, like `from_points` shown above. They also follow the same operator overloads that OpenCV has: two points summed is a point, adding a point to a rectangle shifts it, you can `&` two rectangles to get the intersection as a new rectangle, and so on.

## Image IO

Wrappers for `imread`, `imwrite`, and `imshow` simplify usage by checking errors and allowing path-like objects for path arguments. Additionally, `cvpack` provides functions to read images from a URL (`imread_url`), display to a browser (`imshow_browser`) for statically serving images while working in an interpreter, and displaying images in a Jupyter notebook (`imshow_jupyter`) as HTML directly rather than the typical `plt.imshow` from `matplotlib`. Some other utilities related to display are also included.

```python

from pathlib import Path

import cvpack

for path in Path("folder").glob("*.png"):

    img = cvpack.imread(path)

    big = cvpack.add_grid(cvpack.enlarge(img))

    cvpack.imshow_browser(img, route=str(path))

```

## Video IO

Working with video requires acquiring and releasing resources, so `cvpack` provides context managers for video readers and writers which wrap the classes from OpenCV. Reading video frames is simplified to iterating over the capture object.

```python

import cv2

import cvpack

with cvpack.VideoCapture("video.mp4") as cap:

    with cvpack.VideoWriter("reversed.mp4", fourcc=int(cap.fourcc), fps=cap.fps) as writer:

        for frame in cap:

            flipped = cv2.flip(frame, 0)

            writer.write(flipped)

```