我正在使用Swift做一些視頻處理。升級到El Capitan(和Swift 2)後,我的代碼崩潰了。我將錯誤追溯到CIFilter函數CIColorClamp。這個函數被認爲是鉗位像素值,但實際上會混淆圖像範圍。CIColorClamp在OS X中無法正常工作El Capitan
let _c:CGFloat = 0.05
let minComp = CIVector(x:_c, y:_c, z:_c, w: 1)
let maxComp = CIVector(x:1, y:1, z:1, w: 1)
let clamp: CIFilter = CIFilter(name: "CIColorClamp")!
print("clamp-in \(image.extent)")
clamp.setDefaults()
clamp.setValue(image, forKey: kCIInputImageKey)
clamp.setValue(minComp, forKey: "inputMinComponents")
clamp.setValue(maxComp, forKey: "inputMaxComponents")
print("clamp-out \(clamp.outputImage!.extent)")
上面代碼的輸出:
> clamp-in (6.0, 6.0, 1268.0, 708.0)
CoreAnimation: Warning! CAImageQueueSetOwner() is deprecated and does nothing. Please stop calling this method.
> clamp-out (-8.98846567431158e+307, -8.98846567431158e+307, 1.79769313486232e+308, 1.79769313486232e+308)
,這個調用產生一個內部警告沒有任何灌輸信心的事實!
任何人都可以證實此行爲?我究竟做錯了什麼?