Recent posts

A Derivation of Depth Filter

The depth filter is a useful component in monocular camera visual odometry systems, such as SVO (Semi-Direct Visual Odometry) 1 2. It is designed to estimate depth values from a sequence of images captured by a single camera. The filter operates under the assumption of Gaussian measurement noi...

[Python] How to Compute Faster 2-D Convolution in Python

In image processing, 2-D convolution is a highly useful operation. It can be used for tasks such as blurring, morphology, edge detection, and sharpening. In Python, a naive 2-D convolution method takes a huge computational load for a large image. This post introduces the use of np.lib.stride_t...

[WebGL] Noise Functions

This article summarizes the fundamentals of well-known noise functions, for example, Value, Perlin, Simplex noises, and describes how to use them.

[Three.js] Create a Realistic Sun with Shaders

In the previous article1, we’ve created a realistic Earth. Unlike the Earth that consists of solid elements, the sun is full of gas. In order to render a gas flowing through the surface of the sun, I’ll utilize fractal noise, a.k.a., fractal Brownian motion, that is mentioned at here2. Also, I...

[Three.js] Create a Realistic Earth with Shaders

Let’s return to creating a realistic Earth using Three.js. Unlike the previous Earth1, we are going to render Earth using shader material. First, we will describe the day and night with two different textures, since there are city lights at night. Second, I’ll make an effect for mountain shado...