空间域中的图像滤波入门

什么是空间域中的图像滤波？

在经过空间滤波的图像中，每个输出像素的值是相邻输入像素的加权和。权重由称为卷积核或滤波器的矩阵提供。

Filter Grayscale and Truecolor (RGB) Images using imfilter Function

This example shows how to filter an image with a 5-by-5 averaging filter containing equal weights.

Filter Images Using Predefined Filter

This example shows how to create a type of special filter called an unsharp masking filter, which makes edges and detail in an image appear sharper.

imfilter Boundary Padding Options

When a portion of the convolution or correlation kernel extends past the edge of an image, you can extrapolate image values by zero-padding the image or by replicating boundary pixels.

去噪滤波

去除噪声

噪声是指在图像采集或传输过程中出现的像素值的随机误差。去除噪声可以提高图像质量。

将高斯平滑滤波器应用于图像

此示例说明如何使用不同强度的高斯平滑滤波器来对图像进行模糊处理。该示例包括各向同性和各向异性高斯滤波。

Reduce Noise in Image Gradients

This example shows how to reduce noise associated with computing image gradients.

边缘保持滤波

What is Guided Image Filtering?

Guided image filtering performs edge-preserving smoothing on an image. It uses the content of a second image, called a guidance image, to influence the filtering.

Perform Flash/No-flash Denoising with Guided Filter

This example shows how to reduce noise from an image while using a guidance image to preserve the sharpness of edges.

Segment Thermographic Image after Edge-Preserving Filtering

This example shows how to segment a hot object from the background in a thermographic image.

积分图像域滤波

Integral Image

Integral images are a quick way to represent images for filtering. In an integral image, the value of each pixel is the summation of the pixels above and to the left of it.

Apply Multiple Filters to Integral Image

This example shows how to smooth an image by different amounts by applying box filters of varying sizes to the integral image.

频域滤波

Design Linear Filters in the Frequency Domain

You can design filters that modify the frequency content of images. Filtering in the frequency domain is often faster than filtering in the spatial domain.