lugalu/swiftdithering

Examples

• Bayer 8x8:

<img src= "https://i.imgur.com/6CMZE2w.png"/> - Photo by <a href="https://unsplash.com/@andrazlazic?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Andraz Lazic</a> on <a href="https://unsplash.com/photos/5suzgCS6mIc?utm_source=unsplash&utm_medium=referral&utm_content=creditCopyText">Unsplash</a> <br>

• Floyd-Steinberg:

- 1-bit: <img src="https://i.imgur.com/tyzuqXu.png"/> <br>

- 2-bits: <img src="https://i.imgur.com/UOo2bbZ.png"/>

<br>

Usage

To use the library you will have some access points based on UIImages and CIFilter

CPU:

import SwiftDithering

function yourFunction() {
//Highly Recommended
    Task{
        do{
        let ditheredImage = try image?.applyErrorDifusion(withType: .floydSteinberg)
        //or
        //try image?.applyOrderedDither(withSize: .bayer8x8)
        //or
        //try image?.applyThreshold(withType: .fixed)

        }catch{
          //handle errors here
        }
    }
  
}

the functions also have more accessible parameters, but for simplicity, this example does not, For more details check the Sample/DitherTester/DitherControl and go to any of the retrivedDitheredImages

GPU:

import SwiftDithering

function yourFunction() {
    let filter = OrderedDithering()
    filter.setValuesForKeys([
        "inputImage": inputCIImage,
        "ditherType": ditherType.getCIFilterID(),
        ...
    ])

   return filter?.outputImage
}

I recommend transforming the outputImage to CG before using in IOS, same thing for the respective variants on mac.

Plans And Features

Since is my first time doing something like this a lot of the code is prone to change, I will try to do it in the most non-disruptive way but I cannot guarantee it will work in every single version.

Currently Features: - Bayer matrix; - Floyd Steinberg Error Diffusion; - Stucky Error Difusion. - Fixed Threshold - Random Threshold - Uniform Threshold - Clustered Dots - Central White point - Balanced Centered point - Diagonal clustered - All Ordered Dithers are Now CPU and GPU supported.

## Considerations

• The CPU variants are calculated as sequential and are expensive so tasks and loadings are needed for the user UI.
• Feel free to suggest performance improvements and report any bug that you may find while using this lib
• These dithers are based on the matlab article stored in the archive.today and other research

Package Metadata

Repository: lugalu/swiftdithering

Default branch: main

README: README.md