MPSCNNHelloWorld: Version 1.1, 2016-11-17

Fixes a typo that affected performance

This sample is a port of the open source library, TensorFlow trained networks trained on MNIST Dataset (http://yann.lecun.com/exdb/mnist/) via inference using Metal Performance Shaders. The sample demonstrates how to encode different layers to the GPU and perform image recognition using trained parameters(weights and bias) that have been fetched from, pre-trained and saved network on TensorFlow.

MPSCNNHelloWorld/LICENSE.txt

@@ -0,0 +1,42 @@
+Sample code project: MPSCNNHelloWorld: Simple Digit Detection Convolution Neural Networks (CNN)
+Version: 1.1
+
+IMPORTANT:  This Apple software is supplied to you by Apple
+Inc. ("Apple") in consideration of your agreement to the following
+terms, and your use, installation, modification or redistribution of
+this Apple software constitutes acceptance of these terms.  If you do
+not agree with these terms, please do not use, install, modify or
+redistribute this Apple software.
+
+In consideration of your agreement to abide by the following terms, and
+subject to these terms, Apple grants you a personal, non-exclusive
+license, under Apple's copyrights in this original Apple software (the
+"Apple Software"), to use, reproduce, modify and redistribute the Apple
+Software, with or without modifications, in source and/or binary forms;
+provided that if you redistribute the Apple Software in its entirety and
+without modifications, you must retain this notice and the following
+text and disclaimers in all such redistributions of the Apple Software.
+Neither the name, trademarks, service marks or logos of Apple Inc. may
+be used to endorse or promote products derived from the Apple Software
+without specific prior written permission from Apple.  Except as
+expressly stated in this notice, no other rights or licenses, express or
+implied, are granted by Apple herein, including but not limited to any
+patent rights that may be infringed by your derivative works or by other
+works in which the Apple Software may be incorporated.
+
+The Apple Software is provided by Apple on an "AS IS" basis.  APPLE
+MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
+THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
+OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
+
+IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
+OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
+MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
+AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
+STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+Copyright (C) 2016 Apple Inc. All Rights Reserved.

MPSCNNHelloWorld/MPSCNNHelloWorld/AppDelegate.swift

@@ -0,0 +1,17 @@
+/*
+    Copyright (C) 2016 Apple Inc. All Rights Reserved.
+    See LICENSE.txt for this sample’s licensing information
+
+    Abstract:
+    Application delegate for the App
+*/
+
+import UIKit
+
+@UIApplicationMain
+class AppDelegate: UIResponder, UIApplicationDelegate {
+
+    var window: UIWindow?
+
+}
+

MPSCNNHelloWorld/MPSCNNHelloWorld/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -0,0 +1,86 @@
+{
+  "images" : [
+    {
+      "size" : "29x29",
+      "idiom" : "iphone",
+      "filename" : "mnist-main-58.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "iphone",
+      "filename" : "mnist-main-87.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "iphone",
+      "filename" : "mnist-main-80.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "iphone",
+      "filename" : "mnist-main-120.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "60x60",
+      "idiom" : "iphone",
+      "filename" : "mnist-main-120-2.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "60x60",
+      "idiom" : "iphone",
+      "filename" : "mnist-main-180.png",
+      "scale" : "3x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-29.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "29x29",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-58-2.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-40.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "40x40",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-80-2.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "76x76",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-76.png",
+      "scale" : "1x"
+    },
+    {
+      "size" : "76x76",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-152.png",
+      "scale" : "2x"
+    },
+    {
+      "size" : "83.5x83.5",
+      "idiom" : "ipad",
+      "filename" : "mnist-main-167.png",
+      "scale" : "2x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

MPSCNNHelloWorld/MPSCNNHelloWorld/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}

MPSCNNHelloWorld/MPSCNNHelloWorld/Base.lproj/LaunchScreen.storyboard

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="11019" systemVersion="16A186" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES" initialViewController="01J-lp-oVM">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="11056.3"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="EHf-IW-A2E">
+            <objects>
+                <viewController id="01J-lp-oVM" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="Llm-lL-Icb"/>
+                        <viewControllerLayoutGuide type="bottom" id="xb3-aO-Qok"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="Ze5-6b-2t3">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="iYj-Kq-Ea1" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="53" y="375"/>
+        </scene>
+    </scenes>
+</document>

MPSCNNHelloWorld/MPSCNNHelloWorld/Base.lproj/Main.storyboard

@@ -0,0 +1,96 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="11185.2" systemVersion="16A254d" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" colorMatched="YES" initialViewController="BYZ-38-t0r">
+    <dependencies>
+        <deployment identifier="iOS"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="11151.3"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="tne-QT-ifu">
+            <objects>
+                <viewController id="BYZ-38-t0r" customClass="ViewController" customModule="Digit_Detector" customModuleProvider="target" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="y3c-jy-aDJ"/>
+                        <viewControllerLayoutGuide type="bottom" id="wfy-db-euE"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="8bC-Xf-vdC">
+                        <rect key="frame" x="0.0" y="0.0" width="375" height="667"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <subviews>
+                            <label hidden="YES" opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Accuracy = " textAlignment="center" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Itt-4A-FVR">
+                                <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                                <nil key="textColor"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="fMB-WM-8YO">
+                                <fontDescription key="fontDescription" type="system" pointSize="26"/>
+                                <state key="normal" title="Use MNIST Test Set"/>
+                                <connections>
+                                    <action selector="tappedTestSet:" destination="BYZ-38-t0r" eventType="touchUpInside" id="iwN-td-1sk"/>
+                                </connections>
+                            </button>
+                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="HEd-C6-X5l">
+                                <fontDescription key="fontDescription" type="system" pointSize="26"/>
+                                <state key="normal" title="Detect Digit"/>
+                                <connections>
+                                    <action selector="tappedDetectDigit:" destination="BYZ-38-t0r" eventType="touchUpInside" id="Rtq-vr-h56"/>
+                                </connections>
+                            </button>
+                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="NsO-ek-NfA">
+                                <fontDescription key="fontDescription" type="system" pointSize="25"/>
+                                <state key="normal" title="Clear"/>
+                                <connections>
+                                    <action selector="tappedClear:" destination="BYZ-38-t0r" eventType="touchUpInside" id="aCb-Qa-Y9q"/>
+                                </connections>
+                            </button>
+                            <label hidden="YES" opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="0" textAlignment="center" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="Aa3-61-EIv">
+                                <fontDescription key="fontDescription" type="system" pointSize="23"/>
+                                <nil key="textColor"/>
+                                <nil key="highlightedColor"/>
+                            </label>
+                            <view contentMode="scaleToFill" translatesAutoresizingMaskIntoConstraints="NO" id="PzX-rP-SKt" customClass="DrawView" customModule="Digit_Detector" customModuleProvider="target">
+                                <color key="backgroundColor" white="0.0" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                                <constraints>
+                                    <constraint firstAttribute="height" constant="240" id="cpN-BA-HfR"/>
+                                    <constraint firstAttribute="width" constant="240" id="zZB-ag-7Eh"/>
+                                </constraints>
+                            </view>
+                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="lv9-QR-RxB">
+                                <fontDescription key="fontDescription" type="system" pointSize="26"/>
+                                <state key="normal" title="Use Deep Net"/>
+                                <connections>
+                                    <action selector="tappedDeepButton:" destination="BYZ-38-t0r" eventType="touchUpInside" id="wAp-88-Gdp"/>
+                                </connections>
+                            </button>
+                        </subviews>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                        <constraints>
+                            <constraint firstItem="PzX-rP-SKt" firstAttribute="top" secondItem="NsO-ek-NfA" secondAttribute="bottom" constant="6" id="5Br-ID-zhu"/>
+                            <constraint firstItem="lv9-QR-RxB" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="9CN-JK-3QO"/>
+                            <constraint firstItem="Itt-4A-FVR" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="BPl-aC-Jiq"/>
+                            <constraint firstItem="PzX-rP-SKt" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="LZI-YF-JxH"/>
+                            <constraint firstItem="HEd-C6-X5l" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="P7g-P9-3IL"/>
+                            <constraint firstItem="Aa3-61-EIv" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="Q2L-ju-FT5"/>
+                            <constraint firstItem="NsO-ek-NfA" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="Q6a-Xz-gCB"/>
+                            <constraint firstItem="wfy-db-euE" firstAttribute="top" secondItem="lv9-QR-RxB" secondAttribute="bottom" constant="8" id="RDs-tb-ujw"/>
+                            <constraint firstItem="fMB-WM-8YO" firstAttribute="centerX" secondItem="8bC-Xf-vdC" secondAttribute="centerX" id="T3b-5e-9x9"/>
+                            <constraint firstItem="HEd-C6-X5l" firstAttribute="top" secondItem="PzX-rP-SKt" secondAttribute="bottom" constant="23" id="XZb-1B-Gug"/>
+                            <constraint firstItem="PzX-rP-SKt" firstAttribute="centerY" secondItem="8bC-Xf-vdC" secondAttribute="centerY" id="YHc-FZ-FDx"/>
+                            <constraint firstItem="Aa3-61-EIv" firstAttribute="top" secondItem="HEd-C6-X5l" secondAttribute="bottom" constant="24" id="kKx-jg-CxZ"/>
+                            <constraint firstItem="fMB-WM-8YO" firstAttribute="top" secondItem="y3c-jy-aDJ" secondAttribute="bottom" id="pRd-8b-Hib"/>
+                            <constraint firstItem="Itt-4A-FVR" firstAttribute="top" secondItem="fMB-WM-8YO" secondAttribute="bottom" constant="24" id="zhT-JQ-n6p"/>
+                        </constraints>
+                    </view>
+                    <connections>
+                        <outlet property="DigitView" destination="PzX-rP-SKt" id="bZU-8T-7ZI"/>
+                        <outlet property="accuracyLabel" destination="Itt-4A-FVR" id="REI-58-rzY"/>
+                        <outlet property="predictionLabel" destination="Aa3-61-EIv" id="OkV-W4-Clr"/>
+                    </connections>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="dkx-z0-nzr" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="-3427.734375" y="430.89311859443626"/>
+        </scene>
+    </scenes>
+</document>

MPSCNNHelloWorld/MPSCNNHelloWorld/DrawView.swift

@@ -0,0 +1,93 @@
+/*
+    Copyright (C) 2016 Apple Inc. All Rights Reserved.
+    See LICENSE.txt for this sample’s licensing information
+
+    Abstract:
+    This file has routines for drwaing and detecting user touches (input digit)
+*/
+
+import UIKit
+
+/**
+    This class is used to handle the drawing in the DigitView so we can get user input digit,
+    This class doesn't really have an MPS or Metal going in it, it is just used to get user input
+ */
+class DrawView: UIView {
+
+    // some parameters of how thick a line to draw 15 seems to work 
+    // and we have white drawings on black background just like MNIST needs its input
+    var linewidth = CGFloat(15) { didSet { setNeedsDisplay() } }
+    var color = UIColor.white { didSet { setNeedsDisplay() } }
+
+    // we will keep touches made by user in view in these as a record so we can draw them.
+    var lines: [Line] = []
+    var lastPoint: CGPoint!
+
+    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
+        lastPoint = touches.first!.location(in: self)
+    }
+
+    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
+        let newPoint = touches.first!.location(in: self)
+        // keep all lines drawn by user as touch in record so we can draw them in view
+        lines.append(Line(start: lastPoint, end: newPoint))
+        lastPoint = newPoint
+        // make a draw call
+        setNeedsDisplay()
+    }
+
+    override func draw(_ rect: CGRect) {
+        super.draw(rect)
+
+        let drawPath = UIBezierPath()
+        drawPath.lineCapStyle = .round
+
+        for line in lines{
+            drawPath.move(to: line.start)
+            drawPath.addLine(to: line.end)
+        }
+
+        drawPath.lineWidth = linewidth
+        color.set()
+        drawPath.stroke()
+    }
+
+
+    /**
+        This function gets the pixel data of the view so we can put it in MTLTexture
+
+        - Returns:
+            Void
+     */
+    func getViewContext() -> CGContext? {
+        // our network takes in only grayscale images as input
+        let colorSpace:CGColorSpace = CGColorSpaceCreateDeviceGray()
+
+        // we have 3 channels no alpha value put in the network
+        let bitmapInfo = CGImageAlphaInfo.none.rawValue 
+
+        // this is where our view pixel data will go in once we make the render call
+        let context = CGContext(data: nil, width: 28, height: 28, bitsPerComponent: 8, bytesPerRow: 28, space: colorSpace, bitmapInfo: bitmapInfo)
+
+        // scale and translate so we have the full digit and in MNIST standard size 28x28
+        context!.translateBy(x: 0 , y: 28)
+        context!.scaleBy(x: 28/self.frame.size.width, y: -28/self.frame.size.height)
+
+        // put view pixel data in context
+        self.layer.render(in: context!)
+
+        return context
+    }
+}
+
+/**
+    2 points can give a line and this class is just for that purpose, it keeps a record of a line
+ */
+class Line{
+    var start, end: CGPoint
+
+    init(start: CGPoint, end: CGPoint) {
+        self.start = start
+        self.end   = end
+    }
+}