Source code for imagepypelines.core.Viewer

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# Copyright (c) 2018-2019 Jeff Maggio, Nathan Dileas, Ryan Hartzell
from .imports import import_opencv
cv2 = import_opencv()
import numpy as np
from datetime import datetime

from .img_tools import number_image, norm_dtype
from .util import interpolation_type_check

[docs]class Viewer(object): """ Class to simplify displaying images using opencv windows. Also has functionality to resize images automatically if desired On some systems (or opencv builds), openCV requires a waitkey to be called before displaying the image. This functionality is built in the view function with the argument 'force_waitkey' Args: window_name (str): the name of the window size (2 element tuple, None): (height, width) to resize image to interpolation (cv2 constant): cv2 interpolation flag for resizing enable_frame_counter (bool): whether or not to enable frame counter Attributes: window_name: name of the cv2 window size: size the images are being resized to interpolation: type of interpolation being usef for resizing enable_frame_counter: whether or not the frame counter is enabled frame_counter: index of the frame currently displayed """ def __init__(self, window_name=None, size=None, FFT=False, normalize=False, interpolation=cv2.INTER_NEAREST, enable_frame_counter=False): interpolation_type_check(interpolation) if window_name is None: window_name = self.window_name = str(window_name) self.size = size self._FFT = FFT self._normalize = normalize self.interpolation = interpolation self._enable_frame_counter = enable_frame_counter self.frame_counter = 1
[docs] def open(self): """ opens the image viewer, automatically called in __init__ Args: None Returns: None """ cv2.namedWindow(self.window_name, cv2.WINDOW_AUTOSIZE) return self
[docs] def view(self, frame, force_waitkey=True): """ displays the frame passed into it, reopens itself if it Args: frame (np.ndarray): image to be displayed Returns: force_waitkey (int) = 1: if greater than zero, then call a waitkey for the duration of the time given. this is required on some systems to display the image properly. """ assert isinstance(frame, np.ndarray), "'frame' must be a numpy array" assert frame.ndim in [2, 3], "'frame' must be a 2D or 3D array" assert isinstance(force_waitkey, (int, float)),\ "'force_waitkey' must be an integer" # normalize image band by band (useful for FFT viewing) if self._FFT: if frame.ndim == 2: frame = 20*np.log(np.abs(frame)) if frame.ndim == 3: for b in range(0, 3): frame[:,:,b] = 20*np.log(np.abs(frame[:,:,b])) if self._normalize: frame = norm_dtype(frame) # cast frame dtype to uint8 for display frame = frame.astype(np.uint8) if isinstance(self.size, (tuple, list)): frame = cv2.resize(frame, dsize=(self.size[1], self.size[0]), interpolation=self.interpolation) # add a frame counter to an image thin if self._enable_frame_counter: frame = number_image(frame,self.frame_counter) # displaying the image cv2.imshow(self.window_name, frame) if force_waitkey: cv2.waitKey(force_waitkey) self.frame_counter += 1
[docs] def enable_frame_counter(self): """enable the frame counter""" self._enable_frame_counter = True
[docs] def disable_frame_counter(self): """disable the frame counter""" self._enable_frame_counter = False
[docs] def close(self): """ closes the image viewing window Args: None Returns: None """ cv2.destroyWindow(self.window_name) return self
def __del__(self): self.close()
def main(): import imagepypelines as ip import time img_gen = ip.standard_image_gen() v = ip.ImageViewer('std image test', size=(512,512), enable_frame_counter=True) for img,name in zip(img_gen,ip.list_standard_images()):"displaying ",name) v.view(img) time.sleep(1) if __name__ == "__main__": main()