实现“缩放”功能在AVCamViewController [英] Implementing "Zoom" feature in AVCamViewController

问题描述

我想在我的应用程式中实作「缩放」功能。我的应用程序只支持静态图像，没有视频捕获等。我认为应该直接，但是，我可以缩放图像，然而，当我拍摄一个stillImage，图像出来作为完整的图像，没有放大/输出效果。
我使用Apple提供的AVCamViewController类。
如果你们指出我错过了什么，我会很感激。

I'm trying to implement "Zoom" feature in my app. My app only supports Still Image, no video capturing etc.. i thought it should be straight forward however, i'm able to zoom the image however when i take a stillImage, the image comes out as full image, no zoom-in/out effects. I'm using AVCamViewController class provided by Apple. I would appreciate if you guys point what i'm missing.

- (IBAction)zoomView {
    self.zoomScale =  1 + self.zoomSlider.value;
    self.previewView.transform = CGAffineTransformScale(CGAffineTransformIdentity,self.zoomScale, self.zoomScale);

    DLog(@"zoom scale:%f",self.zoomScale);
}

推荐答案

代码，那么我建议在AVCaptureDeviceInput对象上执行缩放，而不是缩放视图。

If you are using Apple's sample code, then I would suggest performing the zoom on the on the AVCaptureDeviceInput object as opposed to zooming a view.

例如，这是我在UIGestureRecognizer处理pinch手势）：

For instance, this is how I do it within a UIGestureRecognizer (that handles pinch gestures):

dispatch_async(self.sessionQueue, ^{
    AVCaptureDevice *device = [[self getActiveVideoDeviceInput] device];
    NSError *error = nil;
    if ([device lockForConfiguration:&error])
    {
        device.videoZoomFactor = MAX(scale, 1.0);
        [device unlockForConfiguration];
    }
    else
    {
        NSLog(@"%@", error);
    }
});

这篇关于实现“缩放”功能在AVCamViewController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！