UIImage的扩展方法——裁剪图片和等比列缩放图片-翻转-圆形等
@interface UIImage (extend)
//按比例改变图片大小
-(UIImage*)changeImageSizeWithOriginalImage:(UIImage*)image percent:(float)percent;
//圆形
-(UIImage*)circleImage:(UIImage*)image;
//截取部分图像
-(UIImage*)getSubImage:(CGRect)rect;
//等比例缩放
-(UIImage*)scaleToSize:(CGSize)size;
-(UIImage *)rotateImage:(UIImage *)aImage with:(UIImageOrientation)theorient;
-(UIImage *)fixOrientation:(UIImage *)aImage;
@endstatic void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth,
float ovalHeight)
{
float fw, fh;
if (ovalWidth == 0 || ovalHeight == 0) {
CGContextAddRect(context, rect);
return;
}
CGContextSaveGState(context);
CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect));
CGContextScaleCTM(context, ovalWidth, ovalHeight);
fw = CGRectGetWidth(rect) / ovalWidth;
fh = CGRectGetHeight(rect) / ovalHeight;
CGContextMoveToPoint(context, fw, fh/2); // Start at lower right corner
CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1); // Top right corner
CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner
CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner
CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right
CGContextClosePath(context);
CGContextRestoreGState(context);
}
@implementation UIImage (extend)
//按比例改变图片大小
-(UIImage*)changeImageSizeWithOriginalImage:(UIImage*)image percent:(float)percent
{
// change the image size
UIImage *changedImage=nil;
float iwidth=image.size.width*percent;
float iheight=image.size.height*percent;
if (image.size.width != iwidth && image.size.height != iheight)
{
CGSize itemSize = CGSizeMake(iwidth, iheight);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[image drawInRect:imageRect];
changedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
else
{
changedImage = image;
}
return changedImage;
}
//圆角
-(UIImage *) createRoundedRectImage:(UIImage*)image size:(CGSize)size roundSize:(CGSize)roundSize
{
// the size of CGContextRef
int w = size.width;
int h = size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
CGRect rect = CGRectMake(0, 0, w, h);
CGContextBeginPath(context);
addRoundedRectToPath(context, rect, roundSize.width, roundSize.height);
CGContextClosePath(context);
CGContextClip(context);
CGContextDrawImage(context, CGRectMake(0, 0, w, h), image.CGImage);
CGImageRef imageMasked = CGBitmapContextCreateImage(context);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
UIImage *image2 = [UIImage imageWithCGImage:imageMasked];
CGImageRelease(imageMasked);
return image2;
}
//圆形
-(UIImage*)circleImage:(UIImage*)image
{
CGFloat inset = 0.1f;
UIGraphicsBeginImageContext(image.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 2);
CGContextSetStrokeColorWithColor(context, [UIColor clearColor].CGColor);
CGRect rect = CGRectMake(inset, inset, image.size.width - inset * 2.0f, image.size.height - inset * 2.0f);
CGContextAddEllipseInRect(context, rect);
CGContextClip(context);
[image drawInRect:rect];
CGContextAddEllipseInRect(context, rect);
CGContextStrokePath(context);
UIImage *newimg = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newimg;
}
//将image按照theSize大小等比缩放并裁剪
-(UIImage*)autoImage:(UIImage*)image size:(CGSize)theSize
{
if (image == nil)
{
return nil;
}
CGSize imgSize = image.size;
if (imgSize.height == 0 || imgSize.width == 0 || theSize.width == 0 || theSize.height == 0)
{
return nil;
}
CGFloat nx = 0.0f;
CGFloat ny = 0.0f;
CGFloat nw = 0.0f;
CGFloat nh = 0.0f;
UIImage *autoImg = image;
if (imgSize.width/imgSize.height >= theSize.width/theSize.height)
{
autoImg = [self changeImageSizeWithOriginalImage:image percent:theSize.height/imgSize.height];
nw = theSize.width;
nh = autoImg.size.height;
ny = 0;
nx = ABS(autoImg.size.width - theSize.width)/2;
}
else
{
autoImg = [self changeImageSizeWithOriginalImage:image percent:theSize.width/imgSize.width];
nh = theSize.height;
nw = autoImg.size.width;
nx = 0;
ny = ABS(autoImg.size.height - theSize.height)/2;
}
CGRect rect = CGRectMake(nx, ny, nw, nh);
CGImageRef subImageRef = CGImageCreateWithImageInRect(autoImg.CGImage, rect);
CGRect smallBounds = CGRectMake(0, 0, CGImageGetWidth(subImageRef), CGImageGetHeight(subImageRef));
UIGraphicsBeginImageContext(smallBounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextDrawImage(context, smallBounds, subImageRef);
UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];
UIGraphicsEndImageContext();
CGImageRelease(subImageRef);
return smallImage;
}
//截取部分图像
-(UIImage*)getSubImage:(CGRect)rect
{
CGImageRef subImageRef = CGImageCreateWithImageInRect(self.CGImage, rect);
CGRect smallBounds = CGRectMake(0, 0, CGImageGetWidth(subImageRef), CGImageGetHeight(subImageRef));
UIGraphicsBeginImageContext(smallBounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextDrawImage(context, smallBounds, subImageRef);
UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];
UIGraphicsEndImageContext();
return smallImage;
}
//等比例缩放
-(UIImage*)scaleToSize:(CGSize)size
{
CGFloat width = CGImageGetWidth(self.CGImage);
CGFloat height = CGImageGetHeight(self.CGImage);
float verticalRadio = size.height*1.0/height;
float horizontalRadio = size.width*1.0/width;
float radio = 1;
if(verticalRadio>1 && horizontalRadio>1)
{
radio = verticalRadio > horizontalRadio ? horizontalRadio : verticalRadio;
}
else
{
radio = verticalRadio < horizontalRadio ? verticalRadio : horizontalRadio;
}
width = width*radio;
height = height*radio;
int xPos = (size.width - width)/2;
int yPos = (size.height-height)/2;
// 创建一个bitmap的context
// 并把它设置成为当前正在使用的context
UIGraphicsBeginImageContext(size);
// 绘制改变大小的图片
[self drawInRect:CGRectMake(xPos, yPos, width, height)];
// 从当前context中创建一个改变大小后的图片
UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
// 使当前的context出堆栈
UIGraphicsEndImageContext();
// 返回新的改变大小后的图片
return scaledImage;
}
//方向旋转 水平:UIImageOrientationUpMirrored
-(UIImage *)rotateImage:(UIImage *)aImage with:(UIImageOrientation)theorient
{
CGImageRef imgRef = aImage.CGImage;
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGAffineTransform transform = CGAffineTransformIdentity;
CGRect bounds = CGRectMake(0, 0, width, height);
CGFloat scaleRatio = 1;
CGFloat boundHeight;
UIImageOrientation orient = theorient;//aImage.imageOrientation;
switch(orient)
{
case UIImageOrientationUp: //EXIF = 1
transform = CGAffineTransformIdentity;
break;
case UIImageOrientationUpMirrored: //EXIF = 2
transform = CGAffineTransformMakeTranslation(width, 0.0);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
break;
case UIImageOrientationDown: //EXIF = 3
transform = CGAffineTransformMakeTranslation(width, height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationDownMirrored: //EXIF = 4
transform = CGAffineTransformMakeTranslation(0.0, height);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
break;
case UIImageOrientationLeftMirrored: //EXIF = 5
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(height, width);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationLeft: //EXIF = 6
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(0.0, width);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationRightMirrored: //EXIF = 7
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
case UIImageOrientationRight: //EXIF = 8
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(height, 0.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
default:
[NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];
}
UIGraphicsBeginImageContext(bounds.size);
CGContextRef context = UIGraphicsGetCurrentContext();
if (orient == UIImageOrientationRight || orient == UIImageOrientationLeft) {
CGContextScaleCTM(context, -scaleRatio, scaleRatio);
CGContextTranslateCTM(context, -height, 0);
}
else {
CGContextScaleCTM(context, scaleRatio, -scaleRatio);
CGContextTranslateCTM(context, 0, -height);
}
CGContextConcatCTM(context, transform);
CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, width, height), imgRef);
UIImage *imageCopy = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return imageCopy;
}
//方向
-(UIImage *)fixOrientation:(UIImage *)aImage
{
// No-op if the orientation is already correct
if (aImage.imageOrientation == UIImageOrientationUp)
return aImage;
// 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 (aImage.imageOrientation) {
case UIImageOrientationDown:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
transform = CGAffineTransformRotate(transform, M_PI_2);
break;
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);
transform = CGAffineTransformRotate(transform, -M_PI_2);
break;
default:
break;
}
switch (aImage.imageOrientation) {
case UIImageOrientationUpMirrored:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
transform = CGAffineTransformScale(transform, -1, 1);
break;
case UIImageOrientationLeftMirrored:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);
transform = CGAffineTransformScale(transform, -1, 1);
break;
default:
break;
}
// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
CGImageGetBitsPerComponent(aImage.CGImage), 0,
CGImageGetColorSpace(aImage.CGImage),
CGImageGetBitmapInfo(aImage.CGImage));
CGContextConcatCTM(ctx, transform);
switch (aImage.imageOrientation) {
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
// Grr...
CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);
break;
default:
CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.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;
}
@end其他:
Combine two UIImages
To add two UIImages together you need to make use of Graphics Context.
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- (UIImage *)addImage:(UIImage *)image1 toImage:(UIImage *)image2 {
UIGraphicsBeginImageContext(image1.size);
// Draw image1
[image1 drawInRect:CGRectMake(0, 0, image1.size.width, image1.size.height)];
// Draw image2
[image2 drawInRect:CGRectMake(0, 0, image2.size.width, image2.size.height)];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resultingImage;
}
Save UIImage to Photo Album
This is just a one-liner:
UIImageWriteToSavedPhotosAlbum(image, self, @selector(imageSavedToPhotosAlbum: didFinishSavingWithError: contextInfo:), context);
And to know if the save was successful:
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- (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
NSString *message;
NSString *title;
if (!error) {
title = NSLocalizedString(@"SaveSuccessTitle", @"");
message = NSLocalizedString(@"SaveSuccessMessage", @"");
} else {
title = NSLocalizedString(@"SaveFailedTitle", @"");
message = [error description];
}
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title
message:message
delegate:nil
cancelButtonTitle:NSLocalizedString(@"ButtonOK", @"")
otherButtonTitles:nil];
[alert show];
[alert release];
} //UIImage转为灰度图
-(UIImage*)getGrayImage:(UIImage*)sourceImage
{
int width = sourceImage.size.width;
int height = sourceImage.size.height;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
CGColorSpaceRelease(colorSpace);
if (context == NULL) {
return nil;
}
CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);
UIImage *grayImage = [UIImage imageWithCGImage:CGBitmapContextCreateImage(context)];
CGContextRelease(context);
return grayImage;
}// 视图抖动动画
+ (void)shakeView:(UIView *)view
{
float fDuration = 1.2f;
if (view && (fDuration >= 0.1f))
{
CABasicAnimation* shake = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
//设置抖动幅度
shake.fromValue = [NSNumber numberWithFloat:-0.3];
shake.toValue = [NSNumber numberWithFloat:+0.3];
shake.duration = 0.1f;
shake.repeatCount = fDuration/4/0.1f;
shake.autoreverses = YES;
[view.layer addAnimation:shake forKey:@"shakeView"];
}else{}
}
// 对指定视图进行截图
+ (UIImage *)screenShotView:(UIView *)view
{
UIImage *imageRet = nil;
if (view)
{
if(UIGraphicsBeginImageContextWithOptions != NULL)
{
UIGraphicsBeginImageContextWithOptions(view.frame.size, NO, 0.0);
}
else
{
UIGraphicsBeginImageContext(view.frame.size);
}
//获取图像
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
imageRet = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum(imageRet, nil, nil, nil);
}else{APP_ASSERT_STOP}
return imageRet;
}
//将gif图片解析成image数组
+ (NSMutableArray *)praseGIFDataToImageArray:(NSData *)data;
{
NSMutableArray *frames = [[NSMutableArray alloc] init];
CGImageSourceRef src = CGImageSourceCreateWithData((CFDataRef)data, NULL);
CGFloat animationTime = 0.f;
if (src) {
size_t l = CGImageSourceGetCount(src);
frames = [NSMutableArray arrayWithCapacity:l];
for (size_t i = 0; i < l; i++) {
CGImageRef img = CGImageSourceCreateImageAtIndex(src, i, NULL);
NSDictionary *properties = (NSDictionary *)CGImageSourceCopyPropertiesAtIndex(src, i, NULL);
NSDictionary *frameProperties = [properties objectForKey:(NSString *)kCGImagePropertyGIFDictionary];
NSNumber *delayTime = [frameProperties objectForKey:(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
animationTime += [delayTime floatValue];
if (img) {
[frames addObject:[UIImage imageWithCGImage:img]];
CGImageRelease(img);
}
}
CFRelease(src);
}
return frames;
}