iOS-AVFoundation二维码扫描,二维码扫描,图片的无损放大

二维码扫描

扫描实现思路

二维码实现思路

输入设备(用来获取外界信息) 摄像头, 麦克风, 键盘

输出设备 (将收集到的信息, 做解析, 来获取收到的内容)

会话session (用来连接输入和输出设备)

特殊的layer (展示输入设备所采集的信息)

下面上代码:

//

// ViewController.m

// 二维码

//

// Created by VolitationXiaoXing on 15/12/17.

// Copyright © 2016年 dream. All rights reserved.

//

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
#import "HMPreView.h"

@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>
//1. 输入设备(用来获取外界信息)  摄像头, 麦克风, 键盘
@property (nonatomic, strong) AVCaptureDeviceInput *input;

//2. 输出设备 (将收集到的信息, 做解析, 来获取收到的内容)
@property (nonatomic, strong) AVCaptureMetadataOutput *output;

//3. 会话session (用来连接输入和输出设备)
@property (nonatomic, strong) AVCaptureSession *session;

//4. 特殊的layer (展示输入设备所采集的信息)
//@property (nonatomic, strong) AVCaptureVideoPreviewLayer *previewLayer;
@property (nonatomic, strong) HMPreView *preview;

@property (weak, nonatomic) IBOutlet UILabel *label;

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

}

#pragma mark 点击屏幕开始扫描
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
//1.输入设备(用来获取外界信息)  摄像头, 麦克风, 键盘
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
self.input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];

//2.输出设备 (将收集到的信息, 做解析, 来获取收到的内容)
self.output = [AVCaptureMetadataOutput new];

//3.会话session (用来连接输入和输出设备)
self.session = [AVCaptureSession new];

// 会话扫描展示的大小
[self.session setSessionPreset:AVCaptureSessionPresetHigh];

// 会话跟输入和输出设备关联
if ([self.session canAddInput:self.input]) {
[self.session addInput:self.input];
}
if ([self.session canAddOutput:self.output]) {
[self.session addOutput:self.output];
}

//下面两句代码应该写在此处
//制定输出设备的代理, 用来接受返回的数据
[self.output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

//设置元数据类型 二维码QRCode
[self.output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];

//4.特殊的layer (展示输入设备所采集的信息)
//self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
// 大小layer的大小
//self.previewLayer.frame = self.view.bounds;
//[self.view.layer addSublayer:self.previewLayer];

//这个View是一个自定义的View,就是中间一个正方形,中间有一个线上下扫动
self.preview = [[HMPreView alloc] initWithFrame:self.view.bounds];

self.preview.session = self.session;

[self.view addSubview:self.preview];

//5. 启动会话
[self.session startRunning];
}

/**
captureOutput : 输出设备
metadataObjects : 元数据对象的数组
connection : 连接
*/
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
//1. 停止会话
[self.session stopRunning];

//2. 删除layer
//[self.previewLayer removeFromSuperlayer];
[self.preview removeFromSuperview];

//3. 遍历数据获取内容
for (AVMetadataMachineReadableCodeObject *obj in metadataObjects) {
//NSLog(@"obj: %@",obj.stringValue);
self.label.text = obj.stringValue;
}
}

@end

生成二维码

下面是生成二维码的代码,包括了无损放大图片

//
//  ViewController.m
//  QRCodeCreat
//
//  Created by VolitationXiaoXing on 16/7/14.
//  Copyright © 2016年 itcast. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UIImageView *imgView;

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

[filter setDefaults];

NSData *data = [@"这个是二维码中的数据" dataUsingEncoding:NSUTF8StringEncoding];

[filter setValue:data forKey:@"inputMessage"];
//设置容错率
[filter setValue:@"H" forKey:@"inputCorrectionLevel"];

CIImage *coreImage = [filter outputImage];

//  1.无损放大图片
UIImage *QRImage = [self imageWithCIImage:coreImage andSize:self.imgView.bounds.size];

//  2.合并头像
CGSize headSize = CGSizeMake(self.imgView.bounds.size.width * 0.3, self.imgView.bounds.size.height * 0.3);

UIImage *overImage = [self imageWithBackgroundImage:QRImage centerImage:[UIImage imageNamed:@"head"] centerImageSize:headSize];

self.imgView.image = overImage;

}

//  1.无损放大图片这里用到了CIImage与CGImage与UIImage转换

- (UIImage *)imageWithCIImage:(CIImage *)coreImage andSize:(CGSize)size{

// 1.CIImage --> CGImage
CIContext *tempContext = [CIContext contextWithOptions:nil];

CGImageRef originCGImage = [tempContext createCGImage:coreImage fromRect:coreImage.extent];

// 2.创建和size一样大的图形上下文(Bitmap)
CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();

CGContextRef bitmapCtx = CGBitmapContextCreate(NULL, size.width, size.height, 8, 0, cs, kCGImageAlphaNone);

// 3.CGImage 渲染到上下文中
CGContextSetInterpolationQuality(bitmapCtx, kCGInterpolationNone);

CGContextDrawImage(bitmapCtx, CGRectMake(0, 0, size.width, size.height), originCGImage);

// 4.将图形上下文中的图像取出来
CGImageRef QRImage = CGBitmapContextCreateImage(bitmapCtx);

//  释放

// return
return [UIImage imageWithCGImage:QRImage];

}

//  2.合并头像

- (UIImage *)imageWithBackgroundImage:(UIImage *)backgroundImage centerImage:(UIImage *)centerImage centerImageSize:(CGSize)centerSize{

// 1.开启图形上下文
UIGraphicsBeginImageContext(backgroundImage.size);

// 2.先画背景
[backgroundImage drawAtPoint:CGPointZero];

// 3.画头像
CGFloat headW = centerSize.width;
CGFloat headH = centerSize.height;
CGFloat headX = (backgroundImage.size.width - headW) * 0.5;
CGFloat headY = (backgroundImage.size.width - headH) * 0.5;

[centerImage drawInRect:CGRectMake(headX, headY, headW, headH)];

// 4.取图像
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return newImage;

}

@end