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refactored RCImageDecoder
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@aslanyanhaik
aslanyanhaik committed Apr 6, 2020
1 parent 4e74e56 commit 34acd11
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Showing 2 changed files with 102 additions and 138 deletions.
236 changes: 100 additions & 136 deletions Sources/Internal/RCImageDecoder.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -23,10 +23,15 @@
import UIKit

final class RCImageDecoder {

var size = 0
lazy var sectionSize = self.size / 5


var size: Int
var padding = 0
private let sectionSize: Int

init(size: Int) {
self.size = size
sectionSize = size / 5
}
}

extension RCImageDecoder {
Expand All @@ -36,29 +41,20 @@ extension RCImageDecoder {
var points = [CGPoint]()
for side in Side.allCases {
switch side {
case .top:
let x = (size - sectionSize) / 2
let y = 0
let point = try scanVerticalControlPoint(region: (x, y, sectionSize), data: data, side: side)
points.append(point)
case .bottom:
let x = (size - sectionSize) / 2
let y = size - sectionSize
let point = try scanVerticalControlPoint(region: (x, y, sectionSize), data: data, side: side)
points.append(point)
case .left:
let x = 0
let y = (size - sectionSize) / 2
let point = try scanHorizontalControlPoint(region: (x, y, sectionSize), data: data, side: side)
let point = try scanControlPoint(for: data, region: (padding, (size - sectionSize) / 2), side: side)
points.append(point)
case .top:
let point = try scanControlPoint(for: data, region: ((size - sectionSize) / 2, padding), side: side)
points.append(point)
case .right:
let x = size - sectionSize
let y = (size - sectionSize) / 2
let point = try scanHorizontalControlPoint(region: (x, y, sectionSize), data: data, side: side)
let point = try scanControlPoint(for: data, region: (size - sectionSize - padding, (size - sectionSize) / 2), side: side)
points.append(point)
case .bottom:
let point = try scanControlPoint(for: data, region: ((size - sectionSize) / 2, size - sectionSize - padding), side: side)
points.append(point)
}
}
NotificationCenter.default.post(name: NSNotification.Name.init("dots"), object: points)
let image = try fixPerspective(pointer, points: points)
let bits = decode(image)
return bits
Expand All @@ -76,136 +72,104 @@ extension RCImageDecoder {
}

extension RCImageDecoder {
private func scanVerticalControlPoint(region: (x: Int, y: Int, size: Int), data: RCMatrix<UInt8>, side: Side) throws -> CGPoint {
var points = [CGPoint]()
var lastPattern = RCPixelPattern(bit: data[region.x, region.y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one, x: region.x, y: region.y, count: 0)
var pixelPatterns = [lastPattern]
var count = 0
let maxSize = region.size * region.size
while count < maxSize {
let x = count / region.size + region.x
let y = count % region.size + region.y
let bit = data[x, y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one
if lastPattern.x == x, lastPattern.bit == bit {
lastPattern.count += 1
pixelPatterns[pixelPatterns.count - 1] = lastPattern
} else {
lastPattern = RCPixelPattern(bit: bit, x: x, y: y, count: 1)
pixelPatterns.append(lastPattern)
}
count += 1
}
let pixelPatternsBuffer = UnsafeMutableBufferPointer(start: UnsafeMutableRawPointer(mutating: pixelPatterns).assumingMemoryBound(to: RCPixelPattern.self), count: pixelPatterns.count)
guard pixelPatternsBuffer.count >= 5 else { throw RCError.decoding }
var countIndex = 0
while countIndex < pixelPatternsBuffer.count - 5 {
let pattern1 = pixelPatternsBuffer[countIndex]
let pattern2 = pixelPatternsBuffer[countIndex + 1]
let pattern3 = pixelPatternsBuffer[countIndex + 2]
let pattern4 = pixelPatternsBuffer[countIndex + 3]
let pattern5 = pixelPatternsBuffer[countIndex + 4]
countIndex += 1
guard pattern3.count >= 10 else { continue }
let x = pattern1.x
guard pattern2.x == x, pattern3.x == x, pattern4.x == x, pattern5.x == x else { continue }
guard pattern1.bit == .one, pattern2.bit == .zero, pattern3.bit == .one, pattern4.bit == .zero, pattern5.bit == .one else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern1.count) else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern2.count) else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern4.count) else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern5.count) else { continue }
switch side {
case .left:
points.append(CGPoint(x: pattern1.x, y: pattern1.y))
case .right:
points.append(CGPoint(x: CGFloat(pattern5.x) + CGFloat(pattern5.count), y: CGFloat(pattern5.y)))
case .top:
points.append(CGPoint(x: pattern1.x, y: pattern1.y))
case .bottom:
points.append(CGPoint(x: CGFloat(pattern1.x), y: CGFloat(pattern5.y) + CGFloat(pattern5.count)))
private func scanControlPoint(for data: RCMatrix<UInt8>, region: (x: Int, y: Int), side: Side) throws -> CGPoint {

func scan(region: (x: Int, y: Int, size: Int), data: RCMatrix<UInt8>, coordinate: (Int) -> (x: Int, y: Int), comparison: (RCPixelPattern, (x: Int, y: Int)) -> Bool) -> [RCPixelPattern] {
var lastPattern = RCPixelPattern(bit: data[region.x, region.y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one, x: region.x, y: region.y, count: 0)
var pixelPatterns = [lastPattern]
var count = 0
let maxSize = region.size * region.size
while count < maxSize {
let coordinate = coordinate(count)
let bit = data[coordinate.x, coordinate.y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one
if comparison(lastPattern, coordinate), lastPattern.bit == bit {
lastPattern.count += 1
pixelPatterns[pixelPatterns.count - 1] = lastPattern
} else {
lastPattern = RCPixelPattern(bit: bit, x: coordinate.x, y: coordinate.y, count: 1)
pixelPatterns.append(lastPattern)
}
count += 1
}
return pixelPatterns
}
guard !points.isEmpty else { throw RCError.decoding }

let pixelPatterns: [RCPixelPattern]
switch side {
case .left:
return points.sorted(by: {$0.x < $1.x}).first!
case .right:
return points.sorted(by: {$0.x > $1.x}).first!
case .top:
return points.sorted(by: {$0.y < $1.y}).first!
case .bottom:
return points.sorted(by: {$0.y > $1.y}).first!
case .left, .right:
pixelPatterns = scan(region: (region.x, region.y, sectionSize), data: data, coordinate: { count in
let x = count % sectionSize + region.x
let y = count / sectionSize + region.y
return (x, y)
}, comparison: { (pattern, coordinate) in
return pattern.y == coordinate.y
})
case .top, .bottom:
pixelPatterns = scan(region: (region.x, region.y, sectionSize), data: data, coordinate: { count in
let x = count / sectionSize + region.x
let y = count % sectionSize + region.y
return (x, y)
}, comparison: { (pattern, coordinate) in
return pattern.x == coordinate.x
})
}
}



private func scanHorizontalControlPoint(region: (x: Int, y: Int, size: Int), data: RCMatrix<UInt8>, side: Side) throws -> CGPoint {
var points = [CGPoint]()
var lastPattern = RCPixelPattern(bit: data[region.x, region.y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one, x: region.x, y: region.y, count: 0)
var pixelPatterns = [lastPattern]
var count = 0
let maxSize = region.size * region.size
while count < maxSize {
let x = count % region.size + region.x
let y = count / region.size + region.y
let bit = data[x, y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one
if lastPattern.y == y, lastPattern.bit == bit {
lastPattern.count += 1
pixelPatterns[pixelPatterns.count - 1] = lastPattern
} else {
lastPattern = RCPixelPattern(bit: bit, x: x, y: y, count: 1)
pixelPatterns.append(lastPattern)
let controlPoints = try pixelPatterns.withUnsafeBufferPointer { (pixelPatternsBuffer) -> [CGPoint] in
var points = [CGPoint]()
guard pixelPatternsBuffer.count >= 5 else { throw RCError.decoding }
var countIndex = 0
while countIndex < pixelPatternsBuffer.count - 5 {
guard pixelPatternsBuffer[countIndex + 2].count >= 10 else {
countIndex += 1
continue
}
let pattern = (0...4).map({pixelPatternsBuffer[$0 + countIndex]})
countIndex += 1
switch side {
case .left, .right:
let axis = pattern[0].y
guard pattern.allSatisfy({$0.y == axis}) else { continue }
case .top, .bottom:
let axis = pattern[0].x
guard pattern.allSatisfy({$0.x == axis}) else { continue }
}
guard pattern[0].bit == .one, pattern[1].bit == .zero, pattern[2].bit == .one, pattern[3].bit == .zero, pattern[4].bit == .one else { continue }
guard RCConstants.dotPointRange.contains(pattern[2].count / pattern[0].count) else { continue }
guard RCConstants.dotPointRange.contains(pattern[2].count / pattern[1].count) else { continue }
guard RCConstants.dotPointRange.contains(pattern[2].count / pattern[3].count) else { continue }
guard RCConstants.dotPointRange.contains(pattern[2].count / pattern[4].count) else { continue }
switch side {
case .left:
points.append(CGPoint(x: pattern[0].x, y: pattern[0].y))
case .right:
points.append(CGPoint(x: CGFloat(pattern[4].x) + CGFloat(pattern[4].count), y: CGFloat(pattern[4].y)))
case .top:
points.append(CGPoint(x: pattern[0].x, y: pattern[0].y))
case .bottom:
points.append(CGPoint(x: CGFloat(pattern[0].x), y: CGFloat(pattern[4].y) + CGFloat(pattern[4].count)))
}
}
count += 1
return points
}
let pixelPatternsBuffer = UnsafeMutableBufferPointer(start: UnsafeMutableRawPointer(mutating: pixelPatterns).assumingMemoryBound(to: RCPixelPattern.self), count: pixelPatterns.count)
guard pixelPatternsBuffer.count >= 5 else { throw RCError.decoding }
var countIndex = 0
while countIndex < pixelPatternsBuffer.count - 5 {
let pattern1 = pixelPatternsBuffer[countIndex]
let pattern2 = pixelPatternsBuffer[countIndex + 1]
let pattern3 = pixelPatternsBuffer[countIndex + 2]
let pattern4 = pixelPatternsBuffer[countIndex + 3]
let pattern5 = pixelPatternsBuffer[countIndex + 4]
countIndex += 1
guard pattern3.count >= 10 else { continue }
let y = pattern1.y
guard pattern2.y == y, pattern3.y == y, pattern4.y == y, pattern5.y == y else { continue }
guard pattern1.bit == .one, pattern2.bit == .zero, pattern3.bit == .one, pattern4.bit == .zero, pattern5.bit == .one else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern1.count) else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern2.count) else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern4.count) else { continue }
guard RCConstants.dotPointRange.contains(pattern3.count / pattern5.count) else { continue }
guard !controlPoints.isEmpty else { throw RCError.decoding }
return controlPoints.sorted {
switch side {
case .left:
points.append(CGPoint(x: pattern1.x, y: pattern1.y))
return $0.x < $1.x
case .right:
points.append(CGPoint(x: CGFloat(pattern5.x) + CGFloat(pattern5.count), y: CGFloat(pattern5.y)))
return $0.x > $1.x
case .top:
points.append(CGPoint(x: pattern1.x, y: pattern1.y))
return $0.y < $1.y
case .bottom:
points.append(CGPoint(x: CGFloat(pattern1.x), y: CGFloat(pattern5.y) + CGFloat(pattern5.count)))
return $0.y > $1.y
}
}
guard !points.isEmpty else { throw RCError.decoding }
switch side {
case .left:
return points.sorted(by: {$0.x < $1.x}).first!
case .right:
return points.sorted(by: {$0.x > $1.x}).first!
case .top:
return points.sorted(by: {$0.y < $1.y}).first!
case .bottom:
return points.sorted(by: {$0.y > $1.y}).first!
}
}.first!
}

private func fixPerspective(_ data: UnsafeMutablePointer<UInt8>, points: [CGPoint]) throws -> CGImage {
guard let context = generateContext(data: data), let cgImage = context.makeImage() else {
throw RCError.decoding
}
let scale = UIScreen.main.scale
let image = UIGraphicsImageRenderer(size: CGSize(width: CGFloat(size) / scale, height: CGFloat(size) / scale)).image { context in
let image = UIGraphicsImageRenderer(size: CGSize(width: CGFloat(size), height: CGFloat(size))).image { context in
let baseView = UIView(frame: context.format.bounds)
let imageView = UIImageView(frame: context.format.bounds)
baseView.addSubview(imageView)
Expand All @@ -214,9 +178,9 @@ extension RCImageDecoder {
imageView.layer.frame = context.format.bounds
let perspective = RCTransformation(points)
let destination = RCTransformation([CGPoint(x: context.format.bounds.minX, y: context.format.bounds.midY),
CGPoint(x: context.format.bounds.midX, y: context.format.bounds.minY),
CGPoint(x: context.format.bounds.midX, y: context.format.bounds.maxY),
CGPoint(x: context.format.bounds.maxX, y: context.format.bounds.midY)])
CGPoint(x: context.format.bounds.midX, y: context.format.bounds.minY),
CGPoint(x: context.format.bounds.midX, y: context.format.bounds.maxY),
CGPoint(x: context.format.bounds.maxX, y: context.format.bounds.midY)])
let transform = perspective.perspectiveTransform(to: destination)
imageView.transform3D = transform
baseView.drawHierarchy(in: context.format.bounds, afterScreenUpdates: true)
Expand Down
4 changes: 2 additions & 2 deletions Sources/Public/RCCoder.swift
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ import UIKit
public final class RCCoder {

public let configuration: RCCoderConfiguration
private lazy var imageDecoder = RCImageDecoder()
private lazy var imageDecoder = RCImageDecoder(size: 720)
private lazy var imageEncoder = RCImageEncoder()
private lazy var bitCoder = RCBitCoder(configuration: self.configuration)

Expand Down Expand Up @@ -66,6 +66,6 @@ extension RCCoder {
}

func set(scanArea: Int) {
imageDecoder.sectionSize = scanArea
imageDecoder.padding = scanArea
}
}

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