1、前因
由于剪切图片用到下面方法，此方法属于CGImage.h中，通过创建CGImageRef像素位图，可以通过操作存储的像素位来编辑图片。
/* Create an image using the data contained within the subrectangle `rect'
of `image'.
截取图像的一个区域重绘图像*/
CG_EXTERN CGImageRef __nullable CGImageCreateWithImageInRect(
CGImageRef cg_nullable image, CGRect rect)
效果图展示：
代码展示：
UIImage *bgImage =[UIImage imageNamed:@""];
// 上半部
UIImageView *topImgView = [[UIImageView alloc] initWithFrame:CGRectMake(, , CScreenWidth, (CScreenHeight-) * 0.5)];
topImgView.image = [self clipImage:bgImage withRect:CGRectMake(, , imageW, imageH)];
// 下半部
UIImageView *bottomImgView = [[UIImageView alloc] initWithFrame:CGRectMake(, +(CScreenHeight-) * 0.5, CScreenWidth, (CScreenHeight-) * 0.5)];
bottomImgView.image = [self clipImage:bgImage withRect:CGRectMake(, imageH, imageW, imageH)];
[self.view addSubview:topImgView];
[self.view addSubview:bottomImgView];
CGAffineTransform transform = CGAffineTransformIdentity;
transform =CGAffineTransformScale(transform, ., .);
[UIView animateWithDuration:2.0f animations:^{
CGRect topRect = topImgView.frame;
topRect.origin.x -= CScreenWidth;
topImgView.frame = topRect;
topImgView.transform = transform;
CGRect bottomRect = bottomImgView.frame;
bottomRect.origin.x += CScreenWidth;
bottomImgView.frame = bottomRect;
bottomImgView.transform = transform;
} completion:^(BOOL finished) {
[topImgView removeFromSuperview];
[bottomImgView removeFromSuperview];
}];
- (UIImage *)clipImage:(UIImage *)image withRect:(CGRect)rect {
CGRect clipFrame = rect;
CGImageRef refImage = CGImageCreateWithImageInRect(image.CGImage, clipFrame);
UIImage *newImage = [UIImage imageWithCGImage:refImage];
CGImageRelease(refImage);
return newImage;
}2、CGImage.h文件方法简介
typedef CF_ENUM(uint32_t, CGImageAlphaInfo) {
kCGImageAlphaNone, /* For example, RGB. */
kCGImageAlphaPremultipliedLast, /* For example, premultiplied RGBA */
kCGImageAlphaPremultipliedFirst, /* For example, premultiplied ARGB */
kCGImageAlphaLast, /* For example, non-premultiplied RGBA */
kCGImageAlphaFirst, /* For example, non-premultiplied ARGB */
kCGImageAlphaNoneSkipLast, /* For example, RBGX. */
kCGImageAlphaNoneSkipFirst, /* For example, XRGB. */
kCGImageAlphaOnly /* No color data, alpha data only */
};
typedef CF_ENUM(uint32_t, CGImageByteOrderInfo) {
kCGImageByteOrderMask = 0x7000,
kCGImageByteOrderDefault = ( << ),
kCGImageByteOrder16Little = ( << ),
kCGImageByteOrder32Little = ( << ),
kCGImageByteOrder16Big = ( << ),
kCGImageByteOrder32Big = ( << )
} CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);
typedef CF_OPTIONS(uint32_t, CGBitmapInfo) {
kCGBitmapAlphaInfoMask = 0x1F,
kCGBitmapFloatInfoMask = 0xF00,
kCGBitmapFloatComponents = ( << ),
kCGBitmapByteOrderMask = kCGImageByteOrderMask,
kCGBitmapByteOrderDefault = kCGImageByteOrderDefault,
kCGBitmapByteOrder16Little = kCGImageByteOrder16Little,
kCGBitmapByteOrder32Little = kCGImageByteOrder32Little,
kCGBitmapByteOrder16Big = kCGImageByteOrder16Big,
kCGBitmapByteOrder32Big = kCGImageByteOrder32Big
} CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);
#ifdef __BIG_ENDIAN__
# define kCGBitmapByteOrder16Host kCGBitmapByteOrder16Big
# define kCGBitmapByteOrder32Host kCGBitmapByteOrder32Big
#else /* Little endian. */
# define kCGBitmapByteOrder16Host kCGBitmapByteOrder16Little
# define kCGBitmapByteOrder32Host kCGBitmapByteOrder32Little
#endif
/* Return the CFTypeID for CGImageRefs. */
CG_EXTERN CFTypeID CGImageGetTypeID(void)
/* Create an image.
width：图片宽度像素
height：图片高度像素
bitsPerComponent：每个颜色的比特数，例如在rgba-32模式下为8
bitsPerPixel：每个像素的总比特数
bytesPerRow：每一行占用的字节数，注意这里的单位是字节
space：颜色空间模式，例如const CFStringRef kCGColorSpaceGenericRGB 这个函数可以返回一个颜色空间对象。
bitmapInfo：位图像素布局
provider：数据源提供者
decode[]：解码渲染数组
shouldInterpolate：是否抗锯齿
intent：图片相关参数*/
CG_EXTERN CGImageRef __nullable CGImageCreate(size_t width, size_t height,
size_t bitsPerComponent, size_t bitsPerPixel, size_t bytesPerRow,
CGColorSpaceRef cg_nullable space, CGBitmapInfo bitmapInfo,
CGDataProviderRef cg_nullable provider,
const CGFloat * __nullable decode, bool shouldInterpolate,
CGColorRenderingIntent intent)
/* Create an image mask.
创建mask图片图层，可以设置其显示部分与不显示部分达到特殊的效果*/
CG_EXTERN CGImageRef __nullable CGImageMaskCreate(size_t width, size_t height,
size_t bitsPerComponent, size_t bitsPerPixel, size_t bytesPerRow,
CGDataProviderRef cg_nullable provider, const CGFloat * __nullable decode,
bool shouldInterpolate)
/* Return a copy of `image'. Only the image structure itself is copied; the
underlying data is not.
复制一个CGImageRef对象*/
CG_EXTERN CGImageRef __nullable CGImageCreateCopy(CGImageRef cg_nullable image)
/* Create an image from `source', a data provider of JPEG-encoded data.
通过JPEG数据源获取图像 */
CG_EXTERN CGImageRef __nullable CGImageCreateWithJPEGDataProvider(
CGDataProviderRef cg_nullable source, const CGFloat * __nullable decode,
bool shouldInterpolate,
CGColorRenderingIntent intent)
/* Create an image using `source', a data provider for PNG-encoded data.
通过PNG数据源获取图像 */
CG_EXTERN CGImageRef __nullable CGImageCreateWithPNGDataProvider(
CGDataProviderRef cg_nullable source, const CGFloat * __nullable decode,
bool shouldInterpolate,
CGColorRenderingIntent intent)
/* Create an image using the data contained within the subrectangle `rect'
of `image'.
截取图像的一个区域重绘图像*/
CG_EXTERN CGImageRef __nullable CGImageCreateWithImageInRect(
CGImageRef cg_nullable image, CGRect rect)
/* Create a new image from `image' masked by `mask', which may be an image
mask or an image.
截取mask图像的某个区域重绘图像 */
CG_EXTERN CGImageRef __nullable CGImageCreateWithMask(
CGImageRef cg_nullable image, CGImageRef cg_nullable mask)
/* Create a new image from `image' masked by `components'
通过颜色分量数组创建位图*/
CG_EXTERN CGImageRef __nullable CGImageCreateWithMaskingColors(
CGImageRef cg_nullable image, const CGFloat * cg_nullable components)
/* Create a copy of `image', replacing the image's color space with `space'.
Returns NULL if `image' is an image mask, or if the number of components
of `space' isn't the same as the number of components of the color space
of `image'.
通过颜色空间模式复制位图*/
CG_EXTERN CGImageRef __nullable CGImageCreateCopyWithColorSpace(
CGImageRef cg_nullable image, CGColorSpaceRef cg_nullable space)
/* Equivalent to `CFRetain(image)'.
引用计数+1*/
CG_EXTERN CGImageRef cg_nullable CGImageRetain(CGImageRef cg_nullable image)
/* Equivalent to `CFRelease(image)'.
引用计数-1*/
CG_EXTERN void CGImageRelease(CGImageRef cg_nullable image)
/* Return true if `image' is an image mask, false otherwise.
是否是mask图层 */
CG_EXTERN bool CGImageIsMask(CGImageRef cg_nullable image)
/* Return the width of `image'.
获取图像宽度像素*/
CG_EXTERN size_t CGImageGetWidth(CGImageRef cg_nullable image)
/* Return the height of `image'.
获取图像的高度像素*/
CG_EXTERN size_t CGImageGetHeight(CGImageRef cg_nullable image)
//获取图像相应属性
/* Return the number of bits/component of `image'. */
CG_EXTERN size_t CGImageGetBitsPerComponent(CGImageRef cg_nullable image)
/* Return the number of bits/pixel of `image'. */
CG_EXTERN size_t CGImageGetBitsPerPixel(CGImageRef cg_nullable image)
/* Return the number of bytes/row of `image'. */
CG_EXTERN size_t CGImageGetBytesPerRow(CGImageRef cg_nullable image)
/* Return the color space of `image', or NULL if `image' is an image
mask. */
CG_EXTERN CGColorSpaceRef __nullable CGImageGetColorSpace(CGImageRef cg_nullable image)
/* Return the alpha info of `image'. */
CG_EXTERN CGImageAlphaInfo CGImageGetAlphaInfo(CGImageRef cg_nullable image)
/* Return the data provider of `image'. */
CG_EXTERN CGDataProviderRef __nullable CGImageGetDataProvider(CGImageRef cg_nullable image)
/* Return the decode array of `image'. */
CG_EXTERN const CGFloat * __nullable CGImageGetDecode(CGImageRef cg_nullable image)
/* Return the interpolation parameter of `image'. */
CG_EXTERN bool CGImageGetShouldInterpolate(CGImageRef cg_nullable image)
/* Return the rendering intent of `image'. */
CG_EXTERN CGColorRenderingIntent CGImageGetRenderingIntent(cg_nullable CGImageRef image)
/* Return the bitmap info of `image'. */
CG_EXTERN CGBitmapInfo CGImageGetBitmapInfo(CGImageRef cg_nullable image)
/* Return the UTType of `image'. */
CG_EXTERN CFStringRef __nullable CGImageGetUTType(cg_nullable CGImageRef image)