Custom Image Processor

Modify frames using CIImage/CGImage callback
starkdmi · Apr 21, 2024 · efe310a · efe310a
1 parent 6d3272e
commit efe310a
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Showing 5 changed files with 50 additions and 15 deletions.
diff --git a/Sources/Extensions/CGImage+Extensions.swift b/Sources/Extensions/CGImage+Extensions.swift
@@ -31,7 +31,7 @@ public extension CGImage {
         return nil
     }
 
-    /// Resize `CGImage`
+    /// Resize `CGImage` to fit, with aspect ration preserving
     func resizing(to size: CGSize) -> CGImage? {
         let size = self.size.fit(in: size)
 
@@ -44,6 +44,17 @@ public extension CGImage {
         return context.makeImage()
     }
 
+    /// Scale `CGImage` to fill
+    func scaling(to size: CGSize) -> CGImage? {
+        guard let context = CGContext.make(self, width: Int(size.width), height: Int(size.height)) else {
+            return nil
+        }
+
+        context.draw(self, in: CGRect(origin: .zero, size: size))
+
+        return context.makeImage()
+    }
+
     /// Mirror `CGImage`
     func mirroring() -> CGImage? {
         return self.reflect(horizontally: true, vertically: false)
@@ -255,6 +266,7 @@ internal extension CGImage {
         }
 
         // Apply operations in sorted order
+        var imageProcessor: ImageProcessor?
         for operation in operations.sorted() {
             switch operation {
             case let .rotate(value, fill):
@@ -285,8 +297,8 @@ internal extension CGImage {
                         cgImage = mirrored
                     }
                 }
-            /*case .imageProcessing(let function):
-                cgImage = function(cgImage, index)*/
+            case .imageProcessing(let processor):
+                imageProcessor = processor
             }
         }
 
@@ -299,6 +311,11 @@ internal extension CGImage {
             }
         }
 
+        // Apply custom image processor
+        if let imageProcessor = imageProcessor, let image = imageProcessor(nil, cgImage, orientation, index).cgImage {
+            cgImage = image
+        }
+
         // Return modified image
         return cgImage
     }

diff --git a/Sources/Extensions/CIImage+Extensions.swift b/Sources/Extensions/CIImage+Extensions.swift
@@ -171,6 +171,7 @@ internal extension CIImage {
         }
 
         // Apply operations in sorted order
+        var imageProcessor: ImageProcessor?
         for operation in operations.sorted() {
             switch operation {
             case let .rotate(value, fill):
@@ -195,8 +196,8 @@ internal extension CIImage {
                     ciImage = ciImage
                         .transformed(by: CGAffineTransform(scaleX: -1.0, y: 1.0))
                 }
-            /*case .imageProcessing(let function):
-                ciImage = function(ciImage, index)*/
+            case .imageProcessing(let processor):
+                imageProcessor = processor
             }
         }
 
@@ -213,6 +214,11 @@ internal extension CIImage {
             ciImage = ciImage.premultiplyingAlpha().composited(over: background)
         }
 
+        // Apply custom image processor
+        if let imageProcessor = imageProcessor, let image = imageProcessor(ciImage, nil, orientation, index).ciImage {
+            ciImage = image
+        }
+
         // Return modified image
         return ciImage
     }

diff --git a/Sources/Extensions/VImage+Extensions.swift b/Sources/Extensions/VImage+Extensions.swift
@@ -142,6 +142,7 @@ internal extension vImage {
         }
 
         // Apply operations in sorted order
+        var imageProcessor: ImageProcessor?
         let operations = operations.sorted()
         for operation in operations {
             switch operation {
@@ -196,10 +197,9 @@ internal extension vImage {
                         premultipliedAlpha = true
                     }*/
                 }
-            /*case .imageProcessing(let function):
+            case .imageProcessing(let processor):
                 // Custom image processing callback, executed after all the other image operations
-                break
-            */
+                imageProcessor = processor
             }
         }
 
@@ -222,6 +222,11 @@ internal extension vImage {
         }
         try error.check()*/
 
+        // Apply custom image processor
+        if let imageProcessor = imageProcessor, let cgImage = imageProcessor(nil, image, orientation, index).cgImage {
+            image = cgImage
+        }
+
         return image
     }
 }

diff --git a/Sources/Types/Image/ImageOperation.swift b/Sources/Types/Image/ImageOperation.swift
@@ -15,6 +15,12 @@ public enum RotationFill {
     case color(alpha: UInt8, red: UInt8, green: UInt8, blue: UInt8)
 }
 
+/// Image processor type
+/// Only one image passed in based on `preferredFramework` and internal framework support (`CIImage` doesn't support animations)
+/// Return image of the same type to be written - when `CGImage` is not `nil`, modify and return `CGImage` while passing `nil` for `CIImage`
+/// Index used as a frame number (starts with zero), `0` for static images
+public typealias ImageProcessor = (_ ciImage: CIImage?, _ cgImage: CGImage?, _ orientation: CGImagePropertyOrientation?, _ index: Int) -> (ciImage: CIImage?, cgImage: CGImage?)
+
 /// Image operations
 public enum ImageOperation: Equatable, Hashable, Comparable {
     /// Rotation
@@ -29,8 +35,7 @@ public enum ImageOperation: Equatable, Hashable, Comparable {
     case mirror
 
     /// Custom image processing function, appplied after all the other image operations
-    /// Index used as a frame number, `0` for static images
-    // case imageProcessing((_ image: CGImage, _ index: Int) -> CGImage) // vImage, CIImage
+    case imageProcessing(ImageProcessor)
 
     /// Operation priority
     private var priority: Int {
@@ -41,9 +46,9 @@ public enum ImageOperation: Equatable, Hashable, Comparable {
             return 2
         case .mirror:
             return 3
-        /*case .imageProcessing(_):
+        case .imageProcessing(_):
             // Should be executed after all the operations
-            return 100*/
+            return 100
         }
     }
 
@@ -65,8 +70,8 @@ public enum ImageOperation: Equatable, Hashable, Comparable {
             hasher.combine("flip")
         case .mirror:
             hasher.combine("mirror")
-        /*case .imageProcessing(_):
-             hasher.combine("ImageProcessing")*/
+        case .imageProcessing(_):
+             hasher.combine("ImageProcessing")
         }
     }
 
@@ -79,6 +84,8 @@ public enum ImageOperation: Equatable, Hashable, Comparable {
             return true
         case (.mirror, .mirror):
             return true
+        case (.imageProcessing, .imageProcessing):
+            return true
         default:
             return false
         }

diff --git a/Sources/Types/Image/ImageSize.swift b/Sources/Types/Image/ImageSize.swift
@@ -8,7 +8,7 @@ public enum ImageSize: Equatable {
     /// Size to fit in
     case fit(CGSize)
 
-    /// Scale (fill) - no aspect ration preserving
+    /// Scale (fill) - no aspect ratio preserving
     // case scale(CGSize)
 
     /// Cropping size and alignment, `fit` primarly used in video thumbnails