Hello world: Planet Kornia

Welcome to Planet Kornia: a set of tutorial to learn about Computer Vision in PyTorch.

This is the first tutorial showing how one can simply load an image and convert from BGR to RGB using Kornia.

import torch
import kornia
import cv2
import numpy as np

import matplotlib.pyplot as plt

We use OpenCV to load an image to memory represented in a numpy.ndarray

img_bgr: np.ndarray = cv2.imread('./data/arturito.jpeg')  # HxWxC

The image is convert to a 4D torch tensor

x_bgr: torch.tensor = kornia.image_to_tensor(img_bgr)  # 1xCxHxW

Once with a torch tensor we can use any Kornia operator

x_rgb: torch.tensor = kornia.bgr_to_rgb(x_bgr)  # 1xCxHxW

Convert back to numpy to visualize

img_rgb: np.ndarray = kornia.tensor_to_image(x_rgb.byte())  # HxWxC

We use Matplotlib to visualize de results

fig, axs = plt.subplots(1, 2, figsize=(32, 16))
axs = axs.ravel()

axs[0].axis('off')
axs[0].imshow(img_bgr)

axs[1].axis('off')
axs[1].imshow(img_rgb)