Exclude caps with too few images

Config/config_example.json

@@ -3,4 +3,5 @@
     "iterations": 20,
     "server": "https://mydomain.com/caps",
     "authentication": "mysecretkey",
+    "minimumImagesPerCap": 10
 }

Sources/CapTrain.swift

@@ -6,6 +6,8 @@ struct CapTrain: AsyncParsableCommand {
     
     private static let defaultIterations = 10
     
+    private static let defaultMinimumImageCount = 10
+
     @Flag(name: .shortAndLong, help: "Resume the previous training session (default: false)")
     var resume: Bool = false
     
@@ -15,6 +17,9 @@ struct CapTrain: AsyncParsableCommand {
     @Option(name: .shortAndLong, help: "The number of iterations to train (default: 10)")
     var iterations: Int?
     
+    @Option(name: .shortAndLong, help: "The minimum number of images for a cap to be included in training (default: 10)")
+    var minimumImageCount: Int?
+
     @Option(name: .shortAndLong, help: "The url of the caps server to retrieve images and upload the classifier")
     var server: String?
     
@@ -30,6 +35,7 @@ struct CapTrain: AsyncParsableCommand {
     func run() async throws {
         let configurationFile = try configurationFile()
         let iterations = iterations ?? configurationFile?.iterations ?? CapTrain.defaultIterations
+        let minimumCount = minimumImageCount ?? configurationFile?.minimumImagesPerCap ?? CapTrain.defaultMinimumImageCount
         guard let contentFolder = folder ?? configurationFile?.folder else {
             throw TrainingError.missingArguments("folder")
         }
@@ -43,8 +49,9 @@ struct CapTrain: AsyncParsableCommand {
             contentFolder: contentFolder,
             trainingIterations: iterations,
             serverPath: serverPath,
-            authenticationToken: authentication)
         
+            authenticationToken: authentication,
+            minimumImagesPerCap: minimumCount)
         let creator = try ClassifierCreator(configuration: configuration, resume: resume)
         try await creator.run(skipTraining: skipTraining)
     }

Sources/ClassifierCreator.swift

@@ -15,6 +15,9 @@ final class ClassifierCreator {
     
     let configuration: Configuration
     
+    /// The number of images required to include a cap in training
+    let minimumImagesPerCap: Int
+
     let imageDirectory: URL
     
     let thumbnailDirectory: URL
@@ -36,6 +39,7 @@ final class ClassifierCreator {
     init(configuration: Configuration, resume: Bool) throws {
         self.configuration = configuration
         self.server = try configuration.serverUrl()
+        self.minimumImagesPerCap = configuration.minimumImagesPerCap
         let contentDirectory = URL(fileURLWithPath: configuration.contentFolder)
         self.imageDirectory = contentDirectory.appendingPathComponent("images")
         self.sessionDirectory = contentDirectory.appendingPathComponent("session")
@@ -106,7 +110,16 @@ final class ClassifierCreator {
             throw TrainingError.mainImageFolderNotCreated(error)
         }
         let imageCounts = try await getImageCounts()
+            .filter { id, count in
+                // Delete caps with small counts to ensure proper training
+                if count < self.minimumImagesPerCap {
+                    print(info: "Excluding cap \(id) from training (\(count) images)")
+                    return false
+                }
+                return true
+            }
         let missingImageList: [CapImage] = imageCounts
+            .filter { $0.value >= self.minimumImagesPerCap }
             .sorted { $0.key < $1.key }
             .reduce(into: []) { list, pair in
                 let missingImagesForCap: [CapImage] = (0..<pair.value).compactMap { image in
@@ -123,7 +136,7 @@ final class ClassifierCreator {
             print(info: "No missing images to load")
         } else {
             print(info: "Loading \(missingImageList.count) missing images...")
-            try await loadImages(missingImageList)
+            try await loadImagesInBatches(missingImageList)
         }
         
         
@@ -138,7 +151,7 @@ final class ClassifierCreator {
             print(info: "No changed images to load" + suffix)
         } else {
             print(info: "Loading \(filteredChangeList.count) changed images" + suffix)
-            try await loadImages(filteredChangeList)
+            try await loadImagesInBatches(filteredChangeList)
         }
         
         let changedMainImages = changedImageList.filter { $0.image == 0 }.map { $0.cap }
@@ -183,15 +196,20 @@ final class ClassifierCreator {
             let url = imageDirectory.appendingPathComponent(folder)
             do {
                 try FileManager.default.removeItem(at: url)
-                print(info: "Removed unused image folder '\(folder)'")
+                print(info: "Removed item in image folder: '\(folder)'")
             } catch {
                 throw TrainingError.failedToRemoveImageFolder(folder, error)
             }
         }
     }
     
+    private func capFolderUrl(base: URL, cap: Int) -> URL {
+        base.appendingPathComponent(String(format: "%04d", cap))
+    }
+
     private func imageUrl(base: URL, image: CapImage) -> URL {
-        base.appendingPathComponent(String(format: "%04d/%04d-%02d.jpg", image.cap, image.cap, image.image))
+        capFolderUrl(base: base, cap: image.cap)
+            .appendingPathComponent(String(format: "%04d-%02d.jpg", image.cap, image.image))
     }
     
     private func load(image: CapImage) async throws {
@@ -222,7 +240,23 @@ final class ClassifierCreator {
         }
     }
     
-    private func loadImages(_ list: [CapImage]) async throws {
+    private func loadImagesInBatches(_ list: [CapImage], batchSize: Int = 100) async throws {
+        guard !list.isEmpty else {
+            return
+        }
+        print(info: "Loading \(list.count) images...")
+        var startIndex = list.startIndex
+        while startIndex < list.endIndex {
+            let endIndex = min(startIndex + batchSize, list.count)
+            let batch = Array(list[startIndex..<endIndex])
+            print(info: "Completed \(startIndex - list.startIndex) / \(list.count) images")
+            try await loadImageBatch(batch)
+            startIndex = endIndex
+        }
+        print(info: "Completed \(startIndex - list.startIndex) / \(list.count) images")
+    }
+
+    private func loadImageBatch(_ list: [CapImage]) async throws {
         var loadedImageCount = 0
         var errors = [Error]()
         await withTaskGroup(of: Error?.self) { group in

Sources/Configuration.swift

@@ -9,6 +9,8 @@ struct Configuration {
     let serverPath: String
     
     let authenticationToken: String
+
+    let minimumImagesPerCap: Int
 }
 
 extension Configuration {

Sources/ConfigurationFile.swift

@@ -9,6 +9,9 @@ struct ConfigurationFile {
     let server: String?
     
     let authentication: String?
+
+    /// The number of images required to include a cap in training
+    let minimumImagesPerCap: Int?
 }
 
 extension ConfigurationFile: Decodable {

Sources/TrainingError.swift

@@ -87,8 +87,8 @@ extension TrainingError: CustomStringConvertible {
         case .failedToSaveImage(let image, let error):
             return "Failed to save \(image): \(error)"
         case .failedToLoadImages(let expected, let loaded):
-            return "Only \(expected) of \(loaded) images loaded"
         
+            return "Only \(loaded) of \(expected) images loaded"
         case .failedToGetChangedImagesList(let error):
             return "Failed to get list of changed images: \(error)"
         case .invalidEntryInChangeList(let entry):