文章目录

1. UIImage 分类总结

UIImage 分类总结

@(iOS)[UIImage]

[TOC]

修正图片方向

这个使用很常见，特别是在上传图片时，一定要记得修正方向，不然安卓h或者服务端下载下来方向就不对了。
当然这个分类方法是已经有大神写出来了。
image = [image fixOrientation];

/**
 *  修正图片方向
 *
 *  @return 修改后的图片
 */
- (UIImage *)fixOrientation {
    
    // No-op if the orientation is already correct
    if (self.imageOrientation == UIImageOrientationUp) return self;
    
    // We need to calculate the proper transformation to make the image upright.
    // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
    CGAffineTransform transform = CGAffineTransformIdentity;
    
    switch (self.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
            
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;
            
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, self.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationUpMirrored:
            break;
    }
    
    switch (self.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
            
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
        case UIImageOrientationUp:
        case UIImageOrientationDown:
        case UIImageOrientationLeft:
        case UIImageOrientationRight:
            break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, self.size.width, self.size.height,
                                             CGImageGetBitsPerComponent(self.CGImage), 0,
                                             CGImageGetColorSpace(self.CGImage),
                                             CGImageGetBitmapInfo(self.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (self.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            // Grr...
            CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage);
            break;
            
        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage);
            break;
    }
    
    // And now we just create a new UIImage from the drawing context
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}

具体解析，参考这篇文字

指定颜色生成图片

由颜色UIColor直接生成对应的图片，当然要指定尺寸。
image = [UIImage imageWithColor:[UIColor colorWithRed:30 green:190 blue:100 alpha:0.1] andSize:CGSizeMake(100, 100)];

/**
 *  返回指定颜色生成的图片
 *
 *  @param color 颜色
 *  @param size  尺寸
 *
 *  @return
 */
+ (UIImage *)imageWithColor:(UIColor *)color andSize:(CGSize)size
{
    CGRect rect = CGRectMake(0, 0, size.width, size.height);
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, color.CGColor);
    CGContextFillRect(context, rect);
    
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return img;
}

/**
 *  获取指定尺寸（50*50）的图片
 *
 *  @param color 图片颜色
 *  @param name  文本,居中显示
 *
 *  @return
 */
+ (UIImage *)imageWithColor:(UIColor *)color text:(NSString *)name
{
    CGRect rect = CGRectMake(0, 0, 50, 50);
    UIGraphicsBeginImageContextWithOptions(rect.size, NO, 0);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, color.CGColor);
    CGContextFillRect(context, rect);
    [name drawAtPoint:CGPointMake(10, 15) withAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15]}];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    
    UIGraphicsEndImageContext();
    
    return img;
}

图片模糊

生成带有模糊效果的图片，可以直接又UIImage生成，或者直接生成纯色的模糊图片。还有边框
图片模糊
纯色图片模糊

/// 对图片进行模糊处理
+ (UIImage *)gaussianBlurImage:(UIImage *)image andInputRadius:(CGFloat)radius
{
    if (!image) {
        return nil;
    }
    
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];
    
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:kCIInputImageKey];
    [filter setValue:[NSNumber numberWithFloat:radius] forKey:@"inputRadius"];
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]];
    UIImage *resultImage = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    
    return resultImage;
}

/// 由颜色生成模糊图片
+ (UIImage *)gaussianBlurImageWithColor:(UIColor *)color andSize:(CGSize)size andInputRadius:(CGFloat)radius
{
    UIImage *image = [UIImage imageWithColor:color andSize:size];
    if (image) {
        return [UIImage gaussianBlurImage:image andInputRadius:radius];
    }
    else {
        return nil;
    }
}

转换`#FFFFFF`格式颜色

直接生成UIColor类型的颜色，可以指定透明通道

/**
 *  转换#FFFFFF格式颜色
 *
 *  @param string 颜色字符串
 *
 *  @return
 */
+ (UIColor *)RGBColor:(NSString *)string {
    if ([string rangeOfString:@"#"].location != NSNotFound) {
        string = [string stringByReplacingOccurrencesOfString:@"#" withString:@""];
    }
    
    // 十六进制字符串转成整形。
    long colorLong = strtoul([string cStringUsingEncoding:NSUTF8StringEncoding], 0, 16);
    // 通过位与方法获取三色值
    int R = (colorLong & 0xFF0000 )>>16;
    int G = (colorLong & 0x00FF00 )>>8;
    int B = colorLong & 0x0000FF;
    
    //string转color
    UIColor *wordColor = [UIColor colorWithRed:R/255.0 green:G/255.0 blue:B/255.0 alpha:1.0];
    return wordColor;
}


/**
 *  转换#FFFFFF格式颜色
 *
 *  @param string 颜色只付出
 *  @param alpha  指定透明
 *
 *  @return 颜色
 */
+ (UIColor *)RGBColor:(NSString *)string alpha:(CGFloat )alpha{
    if ([string rangeOfString:@"#"].location != NSNotFound) {
        string = [string stringByReplacingOccurrencesOfString:@"#" withString:@""];
    }
    
    // 十六进制字符串转成整形。
    long colorLong = strtoul([string cStringUsingEncoding:NSUTF8StringEncoding], 0, 16);
    // 通过位与方法获取三色值
    int R = (colorLong & 0xFF0000 )>>16;
    int G = (colorLong & 0x00FF00 )>>8;
    int B = colorLong & 0x0000FF;
    
    //string转color
    UIColor *wordColor = [UIColor colorWithRed:R/255.0 green:G/255.0 blue:B/255.0 alpha:alpha];
    return wordColor;
}

透明边框效果图片

给图片添加透明通道，实现透明边框效果

#pragma mark - 透明效果图片
/// 如果含有透明通道就返回TRUE
- (BOOL)hasAlpha {
    // 获取图片的Alpha信息
    CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);
    // 只要满足一下一种就含有透明通道
    return (alpha == kCGImageAlphaFirst ||
            alpha == kCGImageAlphaLast ||
            alpha == kCGImageAlphaPremultipliedFirst ||
            alpha == kCGImageAlphaPremultipliedLast);
}

/// 如果不存在透明通道就添加透明通道并返回结果
- (UIImage *)imageWithAlpha {
    if ([self hasAlpha]) {
        return self; // 已有，直接返回
    }
    
    CGFloat scale = MAX(self.scale, 1.0f);
    CGImageRef imageRef = self.CGImage;
    size_t width = CGImageGetWidth(imageRef)*scale;
    size_t height = CGImageGetHeight(imageRef)*scale;
    
    // 创建位图上下文
    CGContextRef offscreenContext =
    CGBitmapContextCreate(NULL, // 渲染内存，为NULL表示由Quartz自动分配
                          width,//
                          height,
                          8,// bitsPerComponent 每个像素组件的位数
                          0,// 位图每行的字节数，0表示自动
                          CGImageGetColorSpace(imageRef),// 颜色空间
                          kCGBitmapByteOrderDefault | kCGImageAlphaPremultipliedFirst);// 位图信息，这里添加透明通道
    
    
    // 绘制图片
    CGContextDrawImage(offscreenContext, CGRectMake(0, 0, width, height), imageRef);
    CGImageRef imageRefWithAlpha = CGBitmapContextCreateImage(offscreenContext);
    UIImage *imageWithAlpha = [UIImage imageWithCGImage:imageRefWithAlpha scale:self.scale orientation:UIImageOrientationUp];
    
    // 清理内存
    CGContextRelease(offscreenContext);
    CGImageRelease(imageRefWithAlpha);
    
    return imageWithAlpha;
}

/// 给图片增加透明边框，将图片进行缩放
- (UIImage *)transparentBorderImage:(NSUInteger)borderSize {
    // 如果没有透明通道，那就增加一个
    UIImage *image = [self imageWithAlpha];
    CGFloat scale = MAX(self.scale, 1.0f);
    NSUInteger scaledBorderSize = borderSize * scale;
    // 新图片大小
    CGRect newRect = CGRectMake(0, 0, image.size.width * scale + scaledBorderSize * 2, image.size.height * scale + scaledBorderSize * 2);
    
    // 创建位图
    CGContextRef bitmap = CGBitmapContextCreate(NULL,
                                                newRect.size.width,
                                                newRect.size.height,
                                                CGImageGetBitsPerComponent(self.CGImage),
                                                0,
                                                CGImageGetColorSpace(self.CGImage),
                                                CGImageGetBitmapInfo(self.CGImage));
    
    // 绘制位图，预留一个空白的外边框
    CGRect imageLocation = CGRectMake(scaledBorderSize, scaledBorderSize, image.size.width*scale, image.size.height*scale);
    CGContextDrawImage(bitmap, imageLocation, self.CGImage);
    CGImageRef borderImageRef = CGBitmapContextCreateImage(bitmap);
    
    // 创建图片掩码，边框透明，然后和原图合并
    CGImageRef maskImageRef = [self newBorderMask:scaledBorderSize size:newRect.size];
    CGImageRef transparentBorderImageRef = CGImageCreateWithMask(borderImageRef, maskImageRef);
    UIImage *transparentBorderImage = [UIImage imageWithCGImage:transparentBorderImageRef scale:self.scale orientation:UIImageOrientationUp];
    
    // Clean up
    CGContextRelease(bitmap);
    CGImageRelease(borderImageRef);
    CGImageRelease(maskImageRef);
    CGImageRelease(transparentBorderImageRef);
    
    return transparentBorderImage;
}

 *  创建透明边框
 *
 *  @param borderSize 边框宽度
 *  @param size       尺寸
 *
 *  @return
 */
- (CGImageRef)newBorderMask:(NSUInteger)borderSize size:(CGSize)size {
    // 颜色空间-灰度
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
    
    // 图像上下文
    CGContextRef maskContext = CGBitmapContextCreate(NULL,
                                                     size.width,
                                                     size.height,
                                                     8, // 8-bit grayscale
                                                     0,
                                                     colorSpace,
                                                     kCGBitmapByteOrderDefault | kCGImageAlphaNone);
    
    // 透明
    CGContextSetFillColorWithColor(maskContext, [UIColor blackColor].CGColor);
    CGContextFillRect(maskContext, CGRectMake(0, 0, size.width, size.height));
    
    // 中心不透明
    CGContextSetFillColorWithColor(maskContext, [UIColor whiteColor].CGColor);
    CGContextFillRect(maskContext, CGRectMake(borderSize, borderSize, size.width - borderSize * 2, size.height - borderSize * 2));
    
    // 获取图片掩码
    CGImageRef maskImageRef = CGBitmapContextCreateImage(maskContext);
    
    // 清理
    CGContextRelease(maskContext);
    CGColorSpaceRelease(colorSpace);
    
    return maskImageRef;
}

UIImage缩放

UIImage等比例缩放、UIImage自定长宽缩放

UIImage *image = [UIImage imageNamed:@"1"];
NSLog(@"%@",NSStringFromCGSize(image.size));// {1920, 1080}
image = [UIImage reSizeImage:image toSize:CGSizeMake(100, 100)];
// image = [UIImage scaleImage:image toScale:0.5];//{960, 540}
NSLog(@"%@",NSStringFromCGSize(image.size));//{100, 100}

//UIImage等比例缩放
+(UIImage *)scaleImage:(UIImage *)image toScale:(CGFloat)scaleSize

{
    
    UIGraphicsBeginImageContext(CGSizeMake(image.size.width * scaleSize, image.size.height * scaleSize));
    [image drawInRect:CGRectMake(0, 0, image.size.width * scaleSize, image.size.height * scaleSize)];
    UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return scaledImage;
    
}

//UIImage自定长宽缩放
+(UIImage *)reSizeImage:(UIImage *)image toSize:(CGSize)reSize

{
    UIGraphicsBeginImageContext(CGSizeMake(reSize.width, reSize.height));
    [image drawInRect:CGRectMake(0, 0, reSize.width, reSize.height)];
    UIImage *reSizeImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return reSizeImage;
    
}

圆形图片

圆形图片经常用的，直接写一个分类，方便

#pragma mark - Cut
/**
 *  图片剪切为圆形
 *
 *  @param originalImage 原始图片
 *
 *  @return 剪切后的圆形图片
 */
- (UIImage *)roundImage{
    
    //获取size
    CGSize size = [self sizeFromImage:self];
    
    CGRect rect = (CGRect){CGPointZero,size};
    
    //新建一个图片图形上下文
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
    
    //获取上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    
    //绘制圆形路径
    CGContextAddEllipseInRect(ctx, rect);
    
    //剪裁上下文
    CGContextClip(ctx);
    
    //绘制图片
    [self drawInRect:rect];
    
    //取出图片
    UIImage *roundImage = UIGraphicsGetImageFromCurrentImageContext();
    
    //结束上下文
    UIGraphicsEndImageContext();
    
    return roundImage;
}


- (CGSize)sizeFromImage:(UIImage *)image{
    
    CGSize size = image.size;
    
    CGFloat wh =MIN(size.width, size.height);
    
    return CGSizeMake(wh, wh);
}

截屏\截图

屏幕截图
从指定的view截图

/*
 *  直接截屏
 */
+ (UIImage *)cutScreen{
    return [self cutFromView:[UIApplication sharedApplication].keyWindow];
}

/**
 *  从给定UIView中截图：UIView转UIImage
 */
+ (UIImage *)cutFromView:(UIView *)view{
    
    //开启图形上下文
    UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0f);
    
    //获取上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    //在新建的图形上下文中渲染view的layer
    [view.layer renderInContext:context];
    
    [[UIColor clearColor] setFill];
    
    //获取图片
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    
    //关闭图形上下文
    UIGraphicsEndImageContext();
    
    return image;
    
}

/**
 *  从给定UIImage和指定Frame截图：
 */
- (UIImage *)cutWithFrame:(CGRect)frame{
    
    //创建CGImage
    CGImageRef cgimage = CGImageCreateWithImageInRect(self.CGImage, frame);
    
    //创建image
    UIImage *newImage=[UIImage imageWithCGImage:cgimage];
    
    //释放CGImage
    CGImageRelease(cgimage);
    
    return newImage;
}

水印

图片水印，将图片绘制到一张图片任意位置
文字水印，将文字绘制到一张图片任意位置

//  图片水印
image = [image waterWithWaterImage:[UIImage imageNamed:@"2"] direction:ImageWaterDirectCenter waterSize:CGSizeMake(100, 100) marginXY:CGPointMake(0, 0)];
// 文字水印
image =  [image waterWithText:@"哈哈哈" direction:ImageWaterDirectCenter fontColor:[UIColor blackColor] fontPoint:60 marginXY:CGPointMake(0, 0)];

/*
 *  水印方向
 */
typedef enum {
    
    //左上
    ImageWaterDirectTopLeft=0,
    
    //右上
    ImageWaterDirectTopRight,
    
    //左下
    ImageWaterDirectBottomLeft,
    
    //右下
    ImageWaterDirectBottomRight,
    
    //正中
    ImageWaterDirectCenter
    
}ImageWaterDirect;

#pragma mark - 水印
/**
 *  文字水印
 *
 *  @param text      文字
 *  @param direction 文字方向
 *  @param fontColor 文字颜色
 *  @param fontPoint 字体
 *  @param marginXY   对齐点
 *
 *  @return
 */
- (UIImage *)waterWithText:(NSString *)text
                 direction:(ImageWaterDirect)direction
                 fontColor:(UIColor *)fontColor
                 fontPoint:(CGFloat)fontPoint
                  marginXY:(CGPoint)marginXY{
    
    CGSize size = self.size;
    
    CGRect rect = (CGRect){CGPointZero,size};
    
    //新建图片图形上下文
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
    
    //绘制图片
    [self drawInRect:rect];
    
    //绘制文本
    NSDictionary *attr =@{NSFontAttributeName : [UIFont systemFontOfSize:fontPoint],NSForegroundColorAttributeName:fontColor};
    
    CGRect strRect = [self calWidth:text attr:attr direction:direction rect:rect marginXY:marginXY];
    
    [text drawInRect:strRect withAttributes:attr];
    
    //获取图片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    //结束图片图形上下文
    UIGraphicsEndImageContext();
    
    return newImage;
}

/**
 *  绘制图片水印
 *
 *  @param waterImage 图片水印
 *  @param direction  方向
 *  @param waterSize  水印大小
 *  @param marginXY   对齐点
 *
 *  @return
 */
- (UIImage *)waterWithWaterImage:(UIImage *)waterImage
                       direction:(ImageWaterDirect)direction
                       waterSize:(CGSize)waterSize
                        marginXY:(CGPoint)marginXY{
    
    CGSize size = self.size;
    
    CGRect rect = (CGRect){CGPointZero,size};
    
    //新建图片图形上下文
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
    
    //绘制图片
    [self drawInRect:rect];
    
    //计算水印的rect
    CGSize waterImageSize = CGSizeEqualToSize(waterSize, CGSizeZero)?waterImage.size:waterSize;
    CGRect calRect = [self rectWithRect:rect size:waterImageSize direction:direction marginXY:marginXY];
    
    //绘制水印图片
    [waterImage drawInRect:calRect];
    
    //获取图片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    
    //结束图片图形上下文
    UIGraphicsEndImageContext();
    
    return newImage;
}

/**
 *  文字水印位置
 *
 *  @param str       字符串
 *  @param attr      字符串属性
 *  @param direction 方向
 *  @param rect      图片Rect
 *  @param marginXY  对齐点
 *
 *  @return
 */
- (CGRect)calWidth:(NSString *)str
              attr:(NSDictionary *)attr
         direction:(ImageWaterDirect)direction
              rect:(CGRect)rect
          marginXY:(CGPoint)marginXY{
    
    CGSize size =  [str sizeWithAttributes:attr];
    
    CGRect calRect = [self rectWithRect:rect size:size direction:direction marginXY:marginXY];
    
    return calRect;
}

/**
 *  计算水印位置
 *
 *  @param rect      图片rect
 *  @param size      size
 *  @param direction 文字方向
 *  @param marginXY   对齐点
 *
 *  @return
 */
- (CGRect)rectWithRect:(CGRect)rect
                  size:(CGSize)size
             direction:(ImageWaterDirect)direction
              marginXY:(CGPoint)marginXY{
    
    CGPoint point = CGPointZero;
    
    //右上
    if(ImageWaterDirectTopRight == direction) point = CGPointMake(rect.size.width - size.width, 0);
    
    //左下
    if(ImageWaterDirectBottomLeft == direction) point = CGPointMake(0, rect.size.height - size.height);
    
    //右下
    if(ImageWaterDirectBottomRight == direction) point = CGPointMake(rect.size.width - size.width, rect.size.height - size.height);
    
    //正中
    if(ImageWaterDirectCenter == direction) point = CGPointMake((rect.size.width - size.width)*.5f, (rect.size.height - size.height)*.5f);
    
    point.x+=marginXY.x;
    point.y+=marginXY.y;
    
    CGRect calRect = (CGRect){point,size};
    
    return calRect;
}

GIF动画

播放gif格式的动画

#pragma mark - Gif
/**
 *  播放动画
 *
 *  @param data 源文件（图片源）
 *
 *  @return
 */
+ (UIImage *)animatedGIFWithData:(NSData *)data {
    if (!data) {
        return nil;
    }
    
    // 加载所有图片
    CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
    // 图片数量
    size_t count = CGImageSourceGetCount(source);
    
    UIImage *animatedImage;
    // 只有一张，直接加载
    if (count <= 1) {
        animatedImage = [[UIImage alloc] initWithData:data];
    }
    // 多张图片，循环播放
    else {
        NSMutableArray *images = [NSMutableArray array];
        
        NSTimeInterval duration = 0.0f;
        
        for (size_t i = 0; i < count; i++) {
            
            CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
            // 图片播放时间累加
            duration += [self frameDurationAtIndex:i source:source];
            
            [images addObject:[UIImage imageWithCGImage:image
                                                  scale:[UIScreen mainScreen].scale
                                            orientation:UIImageOrientationUp]];
            
            CGImageRelease(image);
        }
        
        if (!duration) {
            duration = (1.0f / 10.0f) * count;
        }
        // 加载动画图片，指定动画播放时间
        animatedImage = [UIImage animatedImageWithImages:images duration:duration];
    }
    
    CFRelease(source);
    
    return animatedImage;
}

/**
 *  计算动画中每一张图片的播放时间
 *
 *  @param index  图片索引
 *  @param source 图片组
 *
 *  @return  播放时间
 */
+ (float)frameDurationAtIndex:(NSUInteger)index source:(CGImageSourceRef)source {
    float frameDuration = 0.1f;
    
    // 字典转换
    CFDictionaryRef cfFrameProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil);
    NSDictionary *frameProperties = (__bridge NSDictionary *)cfFrameProperties;
    NSDictionary *gifProperties = frameProperties[(NSString *)kCGImagePropertyGIFDictionary];
    
    // 如果有延迟时间
    NSNumber *delayTimeUnclampedProp = gifProperties[(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
    if (delayTimeUnclampedProp) {
        frameDuration = [delayTimeUnclampedProp floatValue];
    }
    // 否则就获取播放下一张图片需要等待的时间
    else {
        
        NSNumber *delayTimeProp = gifProperties[(NSString *)kCGImagePropertyGIFDelayTime];
        if (delayTimeProp) {
            frameDuration = [delayTimeProp floatValue];
        }
    }

    // 设置最小值
    if (frameDuration < 0.011f) {
        frameDuration = 0.100f;
    }
    
    CFRelease(cfFrameProperties);
    return frameDuration;
}

/**
 *  播放gif动画
 *
 *  @param name 文件名
 *
 *  @return
 */
+ (UIImage *)animatedGIFNamed:(NSString *)name {
    CGFloat scale = [UIScreen mainScreen].scale;
    
    // 视网膜屏，可能要加载高清图
    if (scale > 1.0f) {
        // 文件名1
        NSString *retinaPath = [[NSBundle mainBundle] pathForResource:[name stringByAppendingString:@"@2x"] ofType:@"gif"];
        
        NSData *data = [NSData dataWithContentsOfFile:retinaPath];
        
        if (data) {
            return [UIImage animatedGIFWithData:data];
        }
        
        // 文件名2
        NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:@"gif"];
        
        data = [NSData dataWithContentsOfFile:path];
        
        if (data) {
            return [UIImage animatedGIFWithData:data];
        }
        
        return [UIImage imageNamed:name];
    }
    // 普通屏幕
    else {
        NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:@"gif"];
        
        NSData *data = [NSData dataWithContentsOfFile:path];
        
        if (data) {
            return [UIImage animatedGIFWithData:data];
        }
        
        return [UIImage imageNamed:name];
    }
}

/**
 *  缩放动画
 *
 *  @param size 大小
 *
 *  @return  
 */
- (UIImage *)animatedImageByScalingAndCroppingToSize:(CGSize)size {
    if (CGSizeEqualToSize(self.size, size) || CGSizeEqualToSize(size, CGSizeZero)) {
        return self;
    }
    
    CGSize scaledSize = size;
    CGPoint thumbnailPoint = CGPointZero;
    
    CGFloat widthFactor = size.width / self.size.width;
    CGFloat heightFactor = size.height / self.size.height;
    CGFloat scaleFactor = (widthFactor > heightFactor) ? widthFactor : heightFactor;
    scaledSize.width = self.size.width * scaleFactor;
    scaledSize.height = self.size.height * scaleFactor;
    
    if (widthFactor > heightFactor) {
        thumbnailPoint.y = (size.height - scaledSize.height) * 0.5;
    }
    else if (widthFactor < heightFactor) {
        thumbnailPoint.x = (size.width - scaledSize.width) * 0.5;
    }
    
    NSMutableArray *scaledImages = [NSMutableArray array];
    
    // 重绘制图片
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0);
    for (UIImage *image in self.images) {
        [image drawInRect:CGRectMake(thumbnailPoint.x, thumbnailPoint.y, scaledSize.width, scaledSize.height)];
        UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        
        [scaledImages addObject:newImage];
    }
    
    UIGraphicsEndImageContext();
    
    return [UIImage animatedImageWithImages:scaledImages duration:self.duration];
}

由CIImage生成UIImage

用到CIImage时可能需要转换，直接生成指定尺寸的UIInage

/**
 *  根据CIImage生成指定大小的UIImage
 *
 *  @param image CIImage
 *  @param size  图片宽度
 */
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size
{
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
    
    // 1.创建bitmap;
    size_t width = CGRectGetWidth(extent) * scale;
    size_t height = CGRectGetHeight(extent) * scale;
    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, extent, bitmapImage);
    
    // 2.保存bitmap到图片
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    UIImage *resultImage = [UIImage imageWithCGImage:scaledImage];
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    CGColorSpaceRelease(cs);
    CGImageRelease(scaledImage);
    return resultImage;
}

转换成黑白图片

将给定图片转换成黑白图片

/**
 *  转成黑白图像
 *
 *  @param sourceImage 原图
 *
 *  @return 黑白图像
 */
+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage
{
    int width = sourceImage.size.width;
    int height = sourceImage.size.height;
    // 指定颜色空间
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
    // 创建图形上下文
    CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
    CGColorSpaceRelease(colorSpace);
    
    if (context == NULL) {
        return nil;
    }
    // 绘制图片
    CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);
    CGImageRef contextRef = CGBitmapContextCreateImage(context);
    // 得到图片
    UIImage *grayImage = [UIImage imageWithCGImage:contextRef];
    CGContextRelease(context);
    CGImageRelease(contextRef);
    
    return grayImage;
}

Bloging

UIImage分类总结

UIImage 分类总结

修正图片方向

指定颜色生成图片

图片模糊

转换`#FFFFFF`格式颜色

透明边框效果图片

UIImage缩放

圆形图片

截屏\截图

水印

GIF动画

由CIImage生成UIImage

转换成黑白图片