File:Discrete Gaussian kernel.svg

Uploaded by Omegatron
Upload date 2017-10-02T01:29:10Z
MIME type image/svg+xml
Dimensions 450 × 538 px
File size 34.8 KB

Summary

Description
English: Comparison of ideal discrete Gaussians based on Bessel functions (solid) versus sampled Gaussian (dashed), for scales values t = 0.5, 1, 2, 4; see Scale space implementation.
Date
Source Own work
Author Omegatron
Other versions

Source code

The logo of Matplotlib – comprehensive library for creating static, animated, and interactive visualizations in Python
The logo of Matplotlib – comprehensive library for creating static, animated, and interactive visualizations in Python
This media was created with Matplotlib (comprehensive library for creating static, animated, and interactive visualizations in Python)
Here is a listing of the source used to create this file.

Deutsch  English  +/−

from scipy.special import iv
import numpy as np

def discrete_gaussian_kernel(n, t):
    T = np.exp(-t) * iv(n, t)
    return T


def sampled_gaussian_kernel(n, t):
    G = 1/np.sqrt(2*np.pi*t) * np.exp(-n**2/(2*t))
    return G


if __name__ == '__main__':
    import matplotlib.pyplot as plt

    plt.figure(figsize=(5, 6))
    for t in (0.5, 1, 2, 4):
        N = 6
        n = np.arange(-N, N+1)
        p = plt.plot(n, discrete_gaussian_kernel(n, t),  '.-',
                     label=f'$t={t:.1f}$')[0]
        plt.plot(n, sampled_gaussian_kernel(n, t),  ':', color=p.get_color())
    plt.grid(True)
    plt.ylim(0, 0.7)
    plt.xlim(-6, 6)
    plt.legend()
    plt.xlabel('$n$')
    plt.ylabel('$T(n,t)$')

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

11 June 2017

35,641 byte

image/svg+xml

7a75ae2d7184ac6912c78a638af53253045c9c72

Category:CC-BY-SA-4.0 Category:Discrete mathematics Category:Images with Matplotlib source code Category:SVG normal distribution Category:Self-published work