PixelEngine 0.2.3

PixelEngine 0.2.3

Maintained by muukii.

  • By
  • muukii

Pixel - Engine • Editor

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Image editor and engine using CoreImage

In Production


Currently accepting PRs that impement these features.


  • ✈️Pretty Good
  • 🚀Blazing Fast (🌀Anyone help us!)


  • Crop
  • Straighten (🌀Anyone help us!)
  • Perspective (🌀Anyone help us!)



  • ColorCube (Look Up Table)
    • Intensity

⚠️ Currently, Pixel does not contain LUT. Demo app has sample LUTs.

And also, here is interesting article


  • Brightness
  • Contrast
  • Saturation
  • Highlights
  • Shadows
  • Temperature
  • GaussianBlur
  • Vignette
  • Color (Shadows / Highlights)
  • Fade
  • Sharpen
  • Clarity
  • HLS (🌀Anyone help us!)



  • Swift 4.2 (Xcode10+)
  • iOS 10+

Getting Started

Demo.app contains the sample code. Please check out Sources/Demo/EditorViewController.swift.

Create instance of PixelEditViewController

let image: UIImage

let controller = PixelEditViewController(image: image)


  • as Modal

⚠️ Currently We need to wrap the controller with UINavigationController. Because, PixelEditViewController needs UINavigationBar.

let controller: PixelEditViewController

let navigationController = UINavigationController(rootViewController: controller)

self.present(navigationController, animated: true, completion: nil)
  • as Push

We can push the controller in UINavigationController.

let controller: PixelEditViewController
self.navigationController.push(controller, animated: true)

Setup Delegate

PixelEditViewController has delegate protocol called PixelEditViewControllerDelegate.

public protocol PixelEditViewControllerDelegate : class {
  func pixelEditViewController(_ controller: PixelEditViewController, didEndEditing editingStack: SquareEditingStack)
  func pixelEditViewControllerDidCancelEditing(in controller: PixelEditViewController)

💡PixelEditViewController does not know how to dismiss or pop by itself. So we need to control PixelEditViewController outside.

Basically, it's like following code, recommend dismiss or pop in methods of delegate.

extension EditorViewController : PixelEditViewControllerDelegate {

  func pixelEditViewController(_ controller: PixelEditViewController, didEndEditing editingStack: SquareEditingStack) {

    self.navigationController?.popToViewController(self, animated: true)

  func pixelEditViewControllerDidCancelEditing(in controller: PixelEditViewController) {
    self.navigationController?.popToViewController(self, animated: true)


Render Image

let editingStack: SquareEditingStack

let image = editingStack.makeRenderer().render(resolution: .full)

Restore editing

We can take current editing as instance of EditingStack from PixelEditViewController.editingStack.

If we want to restore editing after closed PixelEditViewController, we use this.

let editingStack = controller.editingStack
// close editor

// and then when show editor again
let controller = PixelEditViewController(editingStack: editingStack)

Add ColorCubeFilters

We can use LUT(LookUpTable) with CIColorCubeFilter.

LUT is like this (Dimension is 64)

import PixelEngine

let lutImage: UIImage

let filter = FilterColorCube(
  name: "Filter Name",
  identifier: "Filter Identifier",
  lutImage: lutImage,
  dimension: 64

let storage = ColorCubeStorage(filters: [filter])
let controller = PixelEditViewController(image: image, colorCubeStorage: storage)

And also, if we don't specify colorCubeStorage, use default.

// set
ColorCubeStorage.default.filters = filters

// get

Customize Control-UI

We can customize UI for control area.

Customize Built-In Control-UI using override

There is Options struct in PixelEditor. We can create options that fit our usecases.

So, If we need to change ExposureControl, override ExposureControlBase class. Then set that class to Options.

var options = Options.default
options.classes.control.brightnessControl = MyExposureControl.self

let picker = PixelEditViewController(image: image, options: options)

It's like using custom Cell in UICollectionView. If you have any better idea for this, please tell us💡. And also Built-In UI may need expose some properties to customize from subclassing.

Customize whole Control-UI

We can also customize whole UI.

Override options.classes.control.rootControl, then build UI from scratch.

For example, if you don't need the filter section but only the edit mode, you may want to create a control like:

final class EditRootControl : RootControlBase {

   private let containerView = UIView()

   public let colorCubeControl: ColorCubeControlBase

   public lazy var editView = context.options.classes.control.editMenuControl.init(context: context)

   // MARK: - Initializers

   public required init(context: PixelEditContext, colorCubeControl: ColorCubeControlBase) {

       self.colorCubeControl = colorCubeControl

       super.init(context: context, colorCubeControl: colorCubeControl)

       backgroundColor = Style.default.control.backgroundColor

       layout: do {


           containerView.translatesAutoresizingMaskIntoConstraints = false


               containerView.topAnchor.constraint(equalTo: containerView.superview!.topAnchor),
               containerView.leftAnchor.constraint(equalTo: containerView.superview!.leftAnchor),
               containerView.rightAnchor.constraint(equalTo: containerView.superview!.rightAnchor),
               containerView.bottomAnchor.constraint(equalTo: containerView.superview!.bottomAnchor)

   // MARK: - Functions

   override func didMoveToSuperview() {

       if superview != nil {
           editView.frame = containerView.bounds
           editView.autoresizingMask = [.flexibleWidth, .flexibleHeight]


And use it this way:

var options = Options.default
options.classes.control.rootControl = EditRootControl.self

let picker = PixelEditViewController(image: image, options: options)

Filter some edit menu

If there are some edit options you don't need in your app, you can choose edit options you want to ignore:

var options = Options.default
options.classes.control.ignoredEditMenu = [.saturation, .gaussianBlur]
let controller = PixelEditViewController.init(image: UIImage(named: "large")!, options: options)


Strings in UI can be localized with L10n.

import PixelEditor

PixelEditor.L10n.done = "保存"

// or
PixelEditor.L10n.done = NSLocalizedString...



Pixel is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'PixelEngine'
pod 'PixelEditor'


For Carthage, add the following to your Cartfile:

github "muukii/Pixel"


If you need more features, please open issue or submit PR! Muukii may not know the approach to take for implementing them, So your PR will be very helpful.


To develop Pixel, setup environment of development with following code.

$ pod install
$ open Pixel.xcworkspace


Muukii ([email protected])


Pixel is available under the MIT license. See the LICENSE file for more info.

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