# Low Pass Filter

Apply low pass filter to smooth images and reduce noise with adjustable blur algorithms

> Canonical page: https://elysiatools.com/en/tools/image-low-pass

- **Category:** Design

- **Keywords:** image, low-pass, filter, blur, smooth, noise, denoise, soften

## Overview

The Low Pass Filter tool allows you to smooth images and effectively reduce digital noise by applying customizable blur algorithms. Whether you need to soften textures, remove high-frequency artifacts, or create artistic blur effects, this utility provides precise control over the smoothing process.

## Inputs

- **Image File** (file): Upload any image file (JPEG, PNG, WebP, GIF, BMP, TIFF) to smooth and reduce noise
- **Blur Algorithm** (select): Choose the blur algorithm. Gaussian works well for most images
- **Blur Radius** (range): Radius of the blur effect. Higher values create stronger smoothing
- **Blur Strength** (range): Strength of the blur effect. Higher values apply more aggressive smoothing
- **Blur Iterations** (number): Number of blur passes. More iterations = smoother result
- **Preserve Edges** (checkbox): Maintain edge detail while smoothing flat areas
- **Channel Processing** (select): Choose which color channels to process
- **Output Format** (select): Choose output format or keep original. PNG recommended for maximum quality
- **Quality (1-100)** (number): Output quality for lossy formats (JPEG, WebP). Higher = better quality but larger file size

## When to use

- To remove grain or sensor noise from high-ISO digital photographs.
- To soften harsh edges or textures in graphic design assets.
- To prepare images for downscaling by reducing aliasing artifacts.

## How it works

- Upload your image file in any supported format like JPEG, PNG, or WebP.
- Select a blur algorithm, such as Gaussian or Surface Blur, to define the smoothing behavior.
- Adjust the radius, strength, and iteration settings to fine-tune the intensity of the effect.
- Choose your desired output format and quality settings, then process the image to download the smoothed result.

## Use cases

- Denoising vintage or low-light photography to achieve a cleaner look.
- Creating background blur effects for web design elements.
- Softening skin textures or removing blemishes in portrait photography.

## Frequently asked questions

### Which blur algorithm should I choose?

Gaussian Blur is the standard choice for general smoothing. Use Surface Blur if you want to smooth flat areas while preserving sharp edges.

### Can I process multiple images at once?

No, this tool is designed to process one image file at a time.

### What is the purpose of 'Blur Iterations'?

Increasing the number of iterations applies the filter multiple times, resulting in a significantly smoother and more pronounced effect.

### Does this tool support transparency?

Yes, if you upload a PNG or WebP file with transparency, the tool will maintain the alpha channel in the output.

### What is the maximum file size I can upload?

You can upload image files up to 20MB in size.

## Related tools

- [Add Border to Image](https://elysiatools.com/en/tools/image-add-border): Add customizable borders to images with various styles, colors, and widths
- [Add Frame to Image](https://elysiatools.com/en/tools/image-add-frame): Add decorative frames to images with various styles like classic, modern, vintage, and custom designs
- [Add Glow Effect](https://elysiatools.com/en/tools/image-add-glow): Add beautiful glow effects to images with customizable color, intensity, size, and style variations
- [Image Gradient Overlay](https://elysiatools.com/en/tools/image-add-gradient): Add gradient overlay effects to images with customizable colors, directions, and blend modes
- [Image Masking Effect](https://elysiatools.com/en/tools/image-add-masking): Apply masking effects to images using shapes, gradients, or custom masks for creative compositions
- [Add Noise Effect](https://elysiatools.com/en/tools/image-add-noise): Add various types of noise effects to images with customizable intensity and parameters
- [Add Pattern Effect](https://elysiatools.com/en/tools/image-add-pattern): Add geometric pattern overlays to images with customizable colors, size, and rotation
- [Add Reflection Effect](https://elysiatools.com/en/tools/image-add-reflection): Add water reflection effects to images with customizable height, blur, and transparency

## Samples

- [Web Image Processing Python Samples](https://elysiatools.com/en/samples/web-image-processing-python): Web Python image processing examples using PIL/Pillow including reading, saving, resizing, and format conversion
- [Web Image Processing TypeScript Samples](https://elysiatools.com/en/samples/web-image-processing-typescript): Web TypeScript image processing examples including image read/save, scaling, and format conversion
- [Android Image Processing Java Samples](https://elysiatools.com/en/samples/android-image-processing-java): Android Java image processing examples including reading/saving images, scaling, and format conversion
- [Android Image Processing Kotlin Samples](https://elysiatools.com/en/samples/android-image-processing-kotlin): Android Kotlin image processing examples including reading/saving images, scaling, and format conversion

## Related content

- [Image Edge Detection and Convolution Kernel Lab](https://elysiatools.com/en/hubs/image-edge-detection-and-convolution-kernels): Extract the luminance channel, suppress noise with a recorded radius, compare Sobel, Prewitt, Roberts, and Laplacian operators, tune thresholded edge detection, and reproduce the winning result as an explicit convolution kernel.