Table Of Contents
Table Of Contents

Source code for gluoncv.utils.viz.image

"""Visualize image."""
import numpy as np
import mxnet as mx

[docs]def plot_image(img, ax=None, reverse_rgb=False): """Visualize image. Parameters ---------- img : numpy.ndarray or mxnet.nd.NDArray Image with shape `H, W, 3`. ax : matplotlib axes, optional You can reuse previous axes if provided. reverse_rgb : bool, optional Reverse RGB<->BGR orders if `True`. Returns ------- matplotlib axes The ploted axes. Examples -------- from matplotlib import pyplot as plt ax = plot_image(img) plt.show() """ from matplotlib import pyplot as plt if ax is None: # create new axes fig = plt.figure() ax = fig.add_subplot(1, 1, 1) if isinstance(img, mx.nd.NDArray): img = img.asnumpy() img = img.copy() if reverse_rgb: img[:, :, (0, 1, 2)] = img[:, :, (2, 1, 0)] ax.imshow(img.astype(np.uint8)) return ax
[docs]def cv_plot_image(img, scale=1, upperleft_txt=None, upperleft_txt_corner=(10, 100), left_txt_list=None, left_txt_corner=(10, 150), title_txt_list=None, title_txt_corner=(500, 50), canvas_name='demo'): """Visualize image with OpenCV. Parameters ---------- img : numpy.ndarray or mxnet.nd.NDArray Image with shape `H, W, 3`. scale : float The scaling factor of the output image upperleft_txt : str, optional, default is None If presents, will print the string at the upperleft corner upperleft_txt_corner : tuple, optional, default is (10, 100) The bottomleft corner of `upperleft_txt` left_txt_list : list of str, optional, default is None If presents, will print each string in the list close to the left left_txt_corner : tuple, optional, default is (10, 150) The bottomleft corner of `left_txt_list` title_txt_list : list of str, optional, default is None If presents, will print each string in the list close to the top title_txt_corner : tuple, optional, default is (500, 50) The bottomleft corner of `title_txt_list` canvas_name : str, optional, default is 'demo' The name of the canvas to plot the image Examples -------- from matplotlib import pyplot as plt ax = plot_image(img) plt.show() """ from ..filesystem import try_import_cv2 cv2 = try_import_cv2() if isinstance(img, mx.nd.NDArray): img = img.asnumpy() height, width, _ = img.shape img = cv2.resize(img, (int(width * scale), int(height * scale))) if upperleft_txt is not None: font = cv2.FONT_HERSHEY_SIMPLEX bottomLeftCornerOfText = upperleft_txt_corner fontScale = 1 fontColor = (255, 255, 255) thickness = 3 cv2.putText(img, upperleft_txt, bottomLeftCornerOfText, font, fontScale, fontColor, thickness) if left_txt_list is not None: starty = left_txt_corner[1] for txt in left_txt_list: font = cv2.FONT_HERSHEY_SIMPLEX bottomLeftCornerOfText = (left_txt_corner[0], starty) fontScale = 1 fontColor = (255, 255, 255) thickness = 1 cv2.putText(img, txt, bottomLeftCornerOfText, font, fontScale, fontColor, thickness) starty += 30 if title_txt_list is not None: font = cv2.FONT_HERSHEY_SIMPLEX bottomLeftCornerOfText = title_txt_corner fontScale = 1 fontColor = (255, 255, 255) thickness = 3 for txt in title_txt_list: cv2.putText(img, txt, bottomLeftCornerOfText, font, fontScale, fontColor, thickness) bottomLeftCornerOfText = (bottomLeftCornerOfText[0] + 100, bottomLeftCornerOfText[1] + 50) canvas = cv2.cvtColor(img, cv2.COLOR_RGB2BGR) cv2.imshow(canvas_name, canvas)