arcjetCV.utils.video

class arcjetCV.utils.video.Video(path)[source]

Bases: object

Convenience wrapper for opencv video capture.

This class provides a simple interface for working with video files using OpenCV. It encapsulates functionality for reading frames from a video file, setting the current frame, and writing processed frames to a new video file.

Attributes:

fpath (str): Path to the video file. name (str): Name of the video file. folder (str): Directory containing the video file. ext (str): Extension of the video file. cap: OpenCV VideoCapture object for reading video frames. nframes (int): Total number of frames in the video. fps (float): Frames per second of the video. shape (tuple): Shape of the video frames (height, width, channels). last_frame: Last frame read from the video. writer: OpenCV VideoWriter object for writing processed frames. _lock: Threading lock for thread-safe access to the video capture object.

Example: `python video = Video('input_video.mp4') print(video) frame = video.get_frame(0) `

close()[source]

Closes the video capture.

close_writer()[source]

Closes the video writer.

get_frame(index)[source]

Retrieves the frame at the specified index.

Parameters:

index – index of the frame to retrieve

Returns:

RGB frame at the specified index

get_next_frame()[source]

Retrieves the next frame from the video.

Returns:

next frame

get_writer(video_output_name)[source]

Initializes the video writer.

set_frame(index)[source]

Sets the frame at the specified index.

Parameters:

index – index of the frame to set

class arcjetCV.utils.video.VideoMeta(video, path)[source]

Bases: dict

Subclass of dictionary designed to save/load video metadata in JSON format.

This class extends the dictionary class to provide functionality for saving and loading video metadata in JSON format. It also includes methods for resetting frame crop parameters and setting frame crop parameters.

Attributes:

folder (str): Directory containing the video metadata file. name (str): Name of the video metadata file. ext (str): Extension of the video metadata file. path (str): Path to the video metadata file.

Example: `python video = Video('input_video.mp4') # load video video_meta = VideoMeta(video, 'metadata.json') # create/load metadata obj video_meta.write() # write metadata to file `

crop_range()[source]

Returns the crop range.

load(path)[source]

Loads metadata from a JSON file.

Parameters:

path – path to the JSON file

reset_frame_crop()[source]

Resets frame crop parameters to defaults.

set_frame_crop(ymin, ymax, xmin, xmax)[source]

Sets frame crop parameters.

Parameters:

  • ymin – minimum y coordinate

  • ymax – maximum y coordinate

  • xmin – minimum x coordinate

  • xmax – maximum x coordinate

write()[source]

Writes the metadata to a JSON file.

arcjetCV.utils.processor

class arcjetCV.utils.processor.ArcjetProcessor(videometa)[source]

Bases: object

Video frame processor

Primary image processing class: used to read in video data, extract leading edges, hold processed arrays, and output processed data to file.

get_edges_metrics(contour_dict, argdict, offset)[source]

Retrieves edges and metrics from contour dictionary.

Parameters:

  • contour_dict – dictionary containing contours

  • argdict – dictionary containing metrics

  • offset – tuple containing offset values

Returns:

edges: dictionary containing edges argdict: updated dictionary containing metrics

get_flow_direction(frame)[source]

Infers flow direction from the provided frame.

Parameters:

frame – opencv image

Returns flowDirection:

string, “left or “right”

TODO: add support for top/bottom directions

get_image_flags(frame, argdict)[source]

Uses histogram of 8-bit grayscale image (0,255) to classify image type.

Parameters:

  • frame – opencv image

  • argdict – dictionary to store flags

Returns:

dictionary of flags

make_crop_square(frame)[source]

Makes the provided frame square by cropping or padding.

Parameters:

frame – opencv image

Returns:

square_frame: square opencv image offset: list containing offset values

process(frame, argdict)[source]

Processes the given frame.

Parameters:

  • frame – opencv image

  • argdict – dictionary containing segmentation parameters

Returns:

edges: dictionary containing edges argdict: updated dictionary containing metrics

Example: `python processor = ArcjetProcessor(videometa) frame = cv.imread('frame.jpg') argdict = {"SEGMENT_METHOD": "AutoHSV", "MODEL_FRACTION": 0.005} edges, argdict = processor.process(frame, argdict) `

process_all(video: Video, options, first_frame, last_frame, frame_stride, output_prefix='', write_json=True, write_video=False, display_shock=True)[source]

Processes all frames in the video.

Parameters:

  • video – video object (defined in utils/video.py)

  • options – dictionary containing segmentation options

  • first_frame – index of the first frame to process

  • last_frame – index of the last frame to process

  • frame_stride – stride for frame processing

  • write_json – boolean indicating whether to write processed data to JSON file

  • write_video – boolean indicating whether to write processed video

Example: `python video = Video('input_video.mp4') options = {"SEGMENT_METHOD": "AutoHSV", "MODEL_FRACTION": 0.005} processor = ArcjetProcessor(videometa) processor.process_all(video, options, 0, 100, 1, 'output.json', write_video=True) `

segment(img_crop, argdict)[source]

Segments image using one of several methods specified in argdict.

Parameters:

  • img_crop – cropped opencv image

  • argdict – dictionary containing segmentation method and related parameters

Returns:

contour_dict: dictionary containing contours flags: dictionary containing flags

update_video_meta(videometa)[source]

Updates video metadata.

Parameters:

videometa – dictionary containing updated video metadata