1.图片的处理，CoreImage
添加CoreImage的属性，并生成synthesize
@property (nonatomic,strong) CIContext *context;
@property (nonatomic,strong) CIFilter *filter1;
@property (nonatomic,strong) CIFilter *filter2;
@property (nonatomic,strong) CIFilter *filter3;
@property (nonatomic,strong) CIImage *beginImage;
@synthesize context;
@synthesize filter1;
@synthesize filter2;
@synthesize filter3;
@synthesize beginImage;
查看所有的过滤器信息：
- (void)logAllFilters {
NSArray *properties = [CIFilter filterNamesInCategory:kCICategoryBuiltIn];
NSLog(@"count=%d\n,filterName=%@\n",properties.count,properties);
for (NSString *str in properties) {
CIFilter *filter = [CIFilter filterWithName:str];
NSLog(@"%@:\n%@",str,[filter attributes]);
}
}
创建CIImage对象：
#if 1
//通过图片路径创建CIImage对象
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"1" ofType:@"jpg"];
NSURL *fileNameAndPath = [NSURL fileURLWithPath:filePath];
beginImage = [CIImage imageWithContentsOfURL:fileNameAndPath];
#else
/*通过UIImage创建*/
UIImage *image = [UIImage imageNamed:@"1.jpg"];
beginImage = [CIImage imageWithCGImage:image.CGImage];
#endif
创建CIContext：
#if 1
//创建基于GPU的CIContext对象,效率高,但不支持跨应用访问,若在imagePicker里操作会使GPU降为CPU
context = [CIContext contextWithOptions:nil];
#else
//创建基于CPU的CIContext对象
context = [CIContext contextWithOptions:[NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:kCIContextUseSoftwareRenderer]];
#endif
设置过滤器：
filter1 = [CIFilter filterWithName:@"CISepiaTone"];
filter2 = [CIFilter filterWithName:@"CIHueAdjust"];
filter3 = [CIFilter filterWithName:@"CIStraightenFilter"];
增加slider，在valueChanged时添加事件：
/*设置过滤器参数*/
//指定需要处理的图片
[filter1 setValue:beginImage forKey:kCIInputImageKey];
//指定过滤的参数（filter2和filter3的key为inputAngle）
[filter1 setValue:[NSNumber numberWithFloat:slider1.value] forKey:@"inputIntensity"];
//得到过滤后的图片
CIImage *outputImage = [filter1 outputImage];
//转换图片
CGImageRef imgRef = [context createCGImage:outputImage fromRect:[outputImage extent]];
UIImage *newImage = [UIImage imageWithCGImage:imgRef];
//显示图片
imgView.image = newImage;
//释放c对象
CGImageRelease(imgRef);
2.图片保存
存到手机图库：
#import
<AssetsLibrary/AssetsLibrary.h>
CIImage *saveToSave = [filter1 outputImage];
CGImageRef imgRef = [context createCGImage:saveToSave fromRect:[saveToSave extent]];
ALAssetsLibrary *library = [[ALAssetsLibraryalloc] init];
[library writeImageToSavedPhotosAlbum:imgRef metadata:[saveToSave properties] completionBlock:^(NSURL *assetURL,NSError *error){
CGImageRelease(imgRef);
}];
以图片的形式存到沙盒目录下：
- (void)saveImage:(UIImage *)image withName:(NSString
*)nameStr {
NSString *path =
[[NSHomeDirectory()
stringByAppendingPathComponent:@"Documents"]
stringByAppendingPathComponent:nameStr];
[UIImagePNGRepresentation(image) writeToFile:path atomically:NO];
NSString *docPath =
[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES) objectAtIndex:0];
NSLog(@"%@\n存储到docments目录下的文件有:%@",NSHomeDirectory(),[[NSFileManagerdefaultManager] subpathsAtPath:docPath]);
}
以网络缓存的形式:(查找时先将url地址进行MD5加密，按加密后的名称查找)
- (void)saveImage:(UIImage *)image withURLString:(NSString *)urlString {
NSString *path = [NSString stringWithFormat:@"%@/tmp",NSHomeDirectory()];
NSLog(@"%@",path);
[UIImagePNGRepresentation(image) writeToFile:[NSString stringWithFormat:@"%@/%@",path,[urlString MD5Hash]] atomically:NO];
NSLog(@"存储到tmp目录下的文件有:%@",[[NSFileManager defaultManager] subpathsAtPath:path]);
}
3.实现截屏
UIGraphicsBeginImageContext(self.view.frame.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();ImageViewController *ivc = [[ImageViewController alloc] init];
[self.navigationController pushViewController:ivc animated:YES];
ivc.image = image;
在第二个页面添加属性image
图片操作，CoreImage、存储、截屏,码迷,mamicode.com