iOS UIImageView

• jpg 格式转化 png

-(UIImage *)transformPNGWithJPG:(NSString *)imageName
{
    UIImage *image = [UIImage imageNamed:imageName];
    NSData *data = UIImagePNGRepresentation(image);
    UIImage *pngImage = [UIImage imageWithData:data];
    return pngImage;
}

• png 格式转化 jpg

-(UIImage *)transformJPGWithPNG:(NSString *)imageName
{
    UIImage *image = [UIImage imageNamed:imageName];
    NSData *data = UIImageJPEGRepresentation(image, 1);
    UIImage *jpgImage = [UIImage imageWithData:data];
    return jpgImage;
}

将GIF分解为一帧帧 并保存到沙盒中

-(void)decomposeGIF
{
    // 获取GIF数据
    NSString *gifPathSource = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"gif"];
    NSData *data = [NSData dataWithContentsOfFile:gifPathSource];
    CGImageSourceRef sourceRef = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
    // gif 每一帧分解
    size_t count = CGImageSourceGetCount(sourceRef);
    NSMutableArray *tempMutableArray = [[NSMutableArray alloc] init];
    for (size_t i = 0; i < count; i++) {
        CGImageRef imageRef = CGImageSourceCreateImageAtIndex(sourceRef, i, NULL);
        // 将单帧数据转化为 UIImage
        UIImage *image = [UIImage imageWithCGImage:imageRef scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];
        [tempMutableArray addObject:image];
        CGImageRelease(imageRef);
    }
    CFRelease(sourceRef);
    // 将图片保存到 Library/Caches/gifs目录下
    NSString *cacheDirectory = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]; // Library/Caches
    NSString *gifsPath = [NSString stringWithFormat:@"%@/gifs",cacheDirectory];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if (![fileManager fileExistsAtPath:gifsPath]) {
        [fileManager createDirectoryAtPath:gifsPath withIntermediateDirectories:YES attributes:NULL error:NULL];
    }
    for (NSInteger i = 0; i < tempMutableArray.count; i++) {
        UIImage *image = tempMutableArray[i];
        NSData *data = UIImagePNGRepresentation(image);
        NSString *imageName = [NSString stringWithFormat:@"%@/%ld.png",gifsPath,(long)i];
        [data writeToFile:imageName atomically:NO];
    }
    
}

编辑图片- 旋转图片然后保存

• UIImage 分类的实现方法

#import "UIImage+Rotate.h"
#import <QuartzCore/QuartzCore.h>
#import <Accelerate/Accelerate.h>

@implementation UIImage (Rotate)

-(UIImage *)imageRotateIndegree:(CGFloat)degree
{
    size_t width = (size_t)self.size.width * self.scale;
    size_t height = (size_t)self.size.height * self.scale;
    
    CGFloat bytesPerRow = width * 4; // 每行 图片数据字节
    CGImageAlphaInfo alphaInfo = kCGImageAlphaPremultipliedFirst;
    // 配置上下文参数
    CGContextRef contextRef = CGBitmapContextCreate(NULL, width, height, 8, bytesPerRow, CGColorSpaceCreateDeviceRGB(), kCGBitmapByteOrderDefault | alphaInfo);
    if (!contextRef) {
        return nil;
    }
    CGContextDrawImage(contextRef, CGRectMake(0.0f, 0.0f, (CGFloat)width, (CGFloat)height), self.CGImage);
    // 旋转
    UInt8 *data = (UInt8 *)CGBitmapContextGetData(contextRef);
    vImage_Buffer src = {data,height,width,bytesPerRow};
    vImage_Buffer dest = {data,height,width,bytesPerRow};
    Pixel_8888 bgColor = {0,0,0,0};
    vImageRotate_ARGB8888(&src, &dest, NULL, degree, bgColor, kvImageBackgroundColorFill);
    
    CGImageRef rotateImageRef = CGBitmapContextCreateImage(contextRef);
    
    UIImage *rotateImage = [UIImage imageWithCGImage:rotateImageRef scale:self.scale orientation:UIImageOrientationUp];
    return rotateImage;
}

@end

• 实现

UIImage *image = [UIImage imageNamed:@"christmas.jpg"];
    NSData *data = UIImagePNGRepresentation(image);
    UIImage *pngImage = [UIImage imageWithData:data];
    
    UIImage *rotateImage = [pngImage imageRotateIndegree:M_PI / 180 * 45];
    UIImageWriteToSavedPhotosAlbum(rotateImage, NULL, NULL, NULL);

图片剪切

-(UIImage *)imageCutSize:(CGRect)rect
{
    CGImageRef subImageRef = CGImageCreateWithImageInRect(self.CGImage, rect);
    CGRect smallRect = CGRectMake(0.0f, 0.0f, CGImageGetWidth(subImageRef), CGImageGetHeight(subImageRef));
    
    UIGraphicsBeginImageContext(smallRect.size);
    
    CGContextRef contextRef = UIGraphicsGetCurrentContext();
    CGContextDrawImage(contextRef, smallRect, subImageRef);
    UIImage *image = [UIImage imageWithCGImage:subImageRef];
    
    UIGraphicsEndImageContext();
    return image;
}

*实现

UIImage *cutImage = [pngImage imageCutSize:CGRectMake(100.0f, 100.0f, 20.0f, 20.0f)];
    UIImageWriteToSavedPhotosAlbum(cutImage, NULL, NULL, NULL);