php - 读取 EXIF 并确定闪光灯是否闪光

Question

我一直在用我的 PHP 脚本读取一些 EXIF 数据。我想确定某个图像是否使用了闪光灯。这是 EXIF 阅读器返回的值

0x0     = No Flash
0x1     = Fired
0x5     = Fired, Return not detected
0x7     = Fired, Return detected
0x8     = On, Did not fire
0x9     = On, Fired
0xd     = On, Return not detected
0xf     = On, Return detected
0x10    = Off, Did not fire
0x14    = Off, Did not fire, Return not detected
0x18    = Auto, Did not fire
0x19    = Auto, Fired
0x1d    = Auto, Fired, Return not detected
0x1f    = Auto, Fired, Return detected
0x20    = No flash function
0x30    = Off, No flash function
0x41    = Fired, Red-eye reduction
0x45    = Fired, Red-eye reduction, Return not detected
0x47    = Fired, Red-eye reduction, Return detected
0x49    = On, Red-eye reduction
0x4d    = On, Red-eye reduction, Return not detected
0x4f    = On, Red-eye reduction, Return detected
0x50    = Off, Red-eye reduction
0x58    = Auto, Did not fire, Red-eye reduction
0x59    = Auto, Fired, Red-eye reduction
0x5d    = Auto, Fired, Red-eye reduction, Return not detected
0x5f    = Auto, Fired, Red-eye reduction, Return detected

哪些表示已经使用了flash？

最好的问候，姆拉乔

Answer 1

flash 属性实际上是以下标志的组合:

0:  FlashDidNotFire
1:  FlashFired
2:  StrobeReturnLightDetected
4:  StrobeReturnLightNotDetected
8:  CompulsoryFlashMode
16: AutoMode
32: NoFlashFunction
64: RedEyeReductionMode

要检查闪光灯是否已触发，请将闪光灯属性与 1 按位进行运算:

$flashfired = ($exifflashproperty & 1) != 0;