Ios CIImage应该是相等的吗?
因此,苹果的文档表明,Ios CIImage应该是相等的吗?,ios,swift,core-image,ciimage,equatable,Ios,Swift,Core Image,Ciimage,Equatable,因此,苹果的文档表明,CIImage符合equalable。我认为这意味着下面的单元测试将通过。然而,事实并非如此。我对为什么感兴趣 func test_CIImageEqualityShouldWork() { let bundle = NSBundle(forClass: PrototypeTests.self) guard let path = bundle.pathForResource("testImage", ofType: "png") else { return
CIImage
符合equalable
。我认为这意味着下面的单元测试将通过。然而,事实并非如此。我对为什么感兴趣
func test_CIImageEqualityShouldWork() {
let bundle = NSBundle(forClass: PrototypeTests.self)
guard let path = bundle.pathForResource("testImage", ofType: "png") else { return }
guard let image = UIImage(contentsOfFile: path) else { return }
let thingy1 = CIImage(image: image)
let thingy2 = CIImage(image: image)
XCTAssert(thingy1 == thingy2)
}
映像存在,guard
语句都通过,但断言失败,它们不相等
出于兴趣,我已经尝试创建了两次
UIImage
,并对它们进行了比较。这也失败了。所有NSObject
子类都符合equalable
,并且=
函数
对对象调用isEqual:
方法。
isEqual:
方法
ofNSObject
只是比较对象指针,即o1==o2
如果o1
和o2
引用同一对象实例,则保持该状态
例如,见
:
Swift提供==和===运算符和的默认实现
对从
NSObject类。==运算符的默认实现调用
方法,以及===
运算符检查指针是否相等。你不应该忽略这个等式
或从Objective-C导入的类型的标识运算符
isEqual的基本实现:由NSObject类提供
相当于指针相等的身份检查
许多NSObject
子类重写isEqual:
方法(例如NSString
,
NSArray
,NSDate
,…)但不是CIImage
:
let thingy1 = CIImage(image: image)
let thingy2 = CIImage(image: image)
创建两个不同的
CIImage
实例,并将它们比较为“不相等”。所有NSObject
子类都符合equalable
,并且=
函数
对对象调用isEqual:
方法。
isEqual:
方法
ofNSObject
只是比较对象指针,即o1==o2
如果o1
和o2
引用同一对象实例,则保持该状态
例如,见
:
Swift提供==和===运算符和的默认实现
对从
NSObject类。==运算符的默认实现调用
方法,以及===
运算符检查指针是否相等。你不应该忽略这个等式
或从Objective-C导入的类型的标识运算符
isEqual的基本实现:由NSObject类提供
相当于指针相等的身份检查
许多NSObject
子类重写isEqual:
方法(例如NSString
,
NSArray
,NSDate
,…)但不是CIImage
:
let thingy1 = CIImage(image: image)
let thingy2 = CIImage(image: image)
创建两个不同的<代码> CIImage < /Cl>实例,这些比较为“不相等”。< /P> < P> FractMeX是脸谱网从C++到SWIFT的不完整端口。它省略了每像素比较的最后一部分。我的是Swift 4,以下是整个功能:
static func compareWithImage(reference:CGImage, target:CGImage, tolerance:CGFloat) -> Bool {
guard reference.width == target.width && reference.height == target.height else { return false }
let referenceImageSize = CGSize(width:CGFloat(reference.width), height:CGFloat(reference.height))
let targetImageSize = CGSize(width:CGFloat(target.width), height:CGFloat(target.height))
let minBytesPerRow = min(reference.bytesPerRow, target.bytesPerRow)
let referenceImageSizeBytes = Int(referenceImageSize.height) * minBytesPerRow
let referenceImagePixels = calloc(1, referenceImageSizeBytes)
let targetImagePixels = calloc(1, referenceImageSizeBytes)
let referenceImageCtx = CGContext(data: referenceImagePixels,
width: Int(referenceImageSize.width),
height: Int(referenceImageSize.height),
bitsPerComponent: reference.bitsPerComponent,
bytesPerRow: minBytesPerRow,
space: reference.colorSpace!,
bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
let targetImageCtx = CGContext(data: targetImagePixels,
width: Int(targetImageSize.width),
height: Int(targetImageSize.height),
bitsPerComponent: target.bitsPerComponent,
bytesPerRow: minBytesPerRow,
space: target.colorSpace!,
bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)
guard let referenceImageContext = referenceImageCtx, let targetImageContext = targetImageCtx else {
return false
}
referenceImageContext.draw(reference, in:CGRect(x:0, y:0, width:referenceImageSize.width, height:referenceImageSize.height))
targetImageContext.draw(target, in:CGRect(x:0, y:0, width:targetImageSize.width, height:targetImageSize.height))
var imageEqual = true
if(tolerance == 0) {
imageEqual = (memcmp(referenceImagePixels, targetImagePixels, referenceImageSizeBytes) == 0)
} else {
let pixelCount = Int(referenceImageSize.width * referenceImageSize.height)
let p1 = convertUMRPtoUInt32Array(pointer:referenceImagePixels!, length:referenceImageSizeBytes)
let p2 = convertUMRPtoUInt32Array(pointer:targetImagePixels!, length:referenceImageSizeBytes)
var percent:CGFloat = 0
var numDiffPixels = 0
for n in 0..<pixelCount {
if(p1[n] != p2[n]) {
numDiffPixels += 1
percent = CGFloat(numDiffPixels) / CGFloat(pixelCount)
if (percent > tolerance) {
imageEqual = false;
break;
}
}
}
//print(percent)
}
referenceImagePixels?.deallocate(bytes:referenceImageSizeBytes, alignedTo:1)
targetImagePixels?.deallocate(bytes: referenceImageSizeBytes, alignedTo: 1)
return imageEqual
}
static func compareWithImage(参考:CGImage,目标:CGImage,容差:CGFloat)->Bool{
guard reference.width==target.width&&reference.height==target.height else{return false}
让referenceImageSize=CGSize(宽度:CGFloat(reference.width),高度:CGFloat(reference.height))
设targetImageSize=CGSize(宽度:CGFloat(target.width),高度:CGFloat(target.height))
让minBytesPerRow=min(reference.bytesPerRow,target.bytesPerRow)
让referenceImageSizeBytes=Int(referenceImageSize.height)*minBytesPerRow
让referenceImagePixels=calloc(1,referenceImageSizeBytes)
让targetImagePixels=calloc(1,referenceImageSizeBytes)
让referenceImageCtx=CGContext(数据:referenceImagePixels,
宽度:Int(referenceImageSize.width),
高度:Int(referenceImageSize.height),
bitsPerComponent:reference.bitsPerComponent,
bytesPerRow:minBytesPerRow,
空格:引用。颜色空格!,
bitmapInfo:CGImageAlphaInfo.PremultipledLast.rawValue)
设targetImageCtx=CGContext(数据:targetImagePixels,
宽度:Int(targetImageSize.width),
高度:Int(targetImageSize.height),
bitsPerComponent:target.bitsPerComponent,
bytesPerRow:minBytesPerRow,
空间:目标。颜色空间!,
bitmapInfo:CGImageAlphaInfo.PremultipledLast.rawValue)
保护let referenceImageContext=referenceImageCtx,让targetImageContext=targetImageCtx else{
返回错误
}
绘制(引用,in:CGRect(x:0,y:0,宽度:referenceImageSize.width,高度:referenceImageSize.height))
绘制(目标,in:CGRect(x:0,y:0,宽度:targetImageSize.width,高度:targetImageSize.height))
var imageEqual=true
如果(公差==0){
imageEqual=(memcmp(referenceImagePixels、targetImagePixels、referenceImageSizeBytes)==0)
}否则{
让pixelCount=Int(referenceImageSize.width*referenceImageSize.height)
设p1=convertUMRPtoUInt32Array(指针:referenceImagePixels!,长度:referenceImageSizeBytes)
设p2=convertUMRPtoUInt32Array(指针:targetImagePixels!,长度:referenceImageSizeBytes)
变量百分比:CGFloat=0
var numDiffPixels=0
对于0.公差中的n){
imageEqual=false;
打破
}
}
}
//打印(百分比)
}
referenceImagePixels?解除分配(字节:referenceImageSizeBytes,对齐到:1)
塔格