iPhone相机聚焦 [英] iPhone Camera Focussing

问题描述

我使用以下代码聚焦iphone相机。但它没有用。我从Apple的AVCam示例代码中获取此代码。我做错了吗？有没有任何方法可以检测
是否确实关注了iPhone？

I used the below code for focusing the iphone camera. But it is not working. I take this code from the AVCam sample code of Apple. Am I doing anything wrong? Is there any method to detect if the iPhone did focussing?

-(void) focusAtPoint:(CGPoint)point   
{
    AVCaptureDevice *device =  [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];;

    if (device != nil) {            
        if ([device isFocusPointOfInterestSupported] && [device isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {

            NSError *error;

            if ([device lockForConfiguration:&error]) {             
                [device setFocusPointOfInterest:point];             
                [device setFocusMode:AVCaptureFocusModeAutoFocus];              
                [device unlockForConfiguration];                
            } else {                
                NSLog(@"Error in Focus Mode");
            }        

        }
    }
}

推荐答案

[AVCaptureDevice setFocusPointOfInterest：] 的点与视图的触点不同，而是介于两者之间0,0和1,1（见文档）。
所以你必须这样做：

The point for [AVCaptureDevice setFocusPointOfInterest:] is not the same as the touch point of the view, but a point between 0,0 and 1,1 (see docs). So you have to do:

CGPoint point = [touch locationInView:self.cameraView];
point.x /= self.cameraView.frame.size.width;
point.y /= self.cameraView.frame.size.height;
[self focusAtPoint:point];

这篇关于iPhone相机聚焦的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！