iOS图片压缩方法

#define KCompressibilityFactor 1280.00

@implementationWeChatJPEGImager

#pragma mark - 压缩一张图片 最大宽高1280 类似于微信算法

- (UIImage*)getJPEGImagerImg:(UIImage*)image{

CGFloat oldImg_WID = image.size.width;

CGFloat oldImg_HEI = image.size.height;

//CGFloat aspectRatio = oldImg_WID/oldImg_HEI;//宽高比

if(oldImg_WID > KCompressibilityFactor || oldImg_HEI > KCompressibilityFactor){

//超过设置的最大宽度 先判断那个边最长

if(oldImg_WID > oldImg_HEI){

//宽度大于高度

oldImg_HEI = (KCompressibilityFactor* oldImg_HEI)/oldImg_WID;

oldImg_WID = KCompressibilityFactor;

}else{

oldImg_WID = (KCompressibilityFactor* oldImg_WID)/oldImg_HEI;

oldImg_HEI = KCompressibilityFactor;

}

}

UIImage*newImg = [selfimageWithImage:imagescaledToSize:CGSizeMake(oldImg_WID, oldImg_HEI)];

NSData*dJpeg =nil;

if(UIImagePNGRepresentation(newImg)==nil) {

dJpeg = UIImageJPEGRepresentation(newImg,0.5);

}else{

dJpeg = UIImagePNGRepresentation(newImg);

}

return[UIImageimageWithData:dJpeg];

}

#pragma mark - 压缩多张图片 最大宽高1280 类似于微信算法

- (NSArray*)getJPEGImagerImgArr:(NSArray*)imageArr{

NSMutableArray*newImgArr = [NSMutableArraynew];

for(inti =0; i

UIImage*newImg = [selfgetJPEGImagerImg:imageArr[i]];

[newImgArraddObject:newImg];

}

returnnewImgArr;

}

#pragma mark - 压缩一张图片 自定义最大宽高

- (UIImage*)getJPEGImagerImg:(UIImage*)imagecompressibilityFactor:(CGFloat)compressibilityFactor{

CGFloat oldImg_WID = image.size.width;

CGFloat oldImg_HEI = image.size.height;

//CGFloat aspectRatio = oldImg_WID/oldImg_HEI;//宽高比

if(oldImg_WID > compressibilityFactor || oldImg_HEI > compressibilityFactor){

//超过设置的最大宽度 先判断那个边最长

if(oldImg_WID > oldImg_HEI){

//宽度大于高度

oldImg_HEI = (compressibilityFactor* oldImg_HEI)/oldImg_WID;

oldImg_WID = compressibilityFactor;

}else{

oldImg_WID = (compressibilityFactor* oldImg_WID)/oldImg_HEI;

oldImg_HEI = compressibilityFactor;

}

}

UIImage*newImg = [selfimageWithImage:imagescaledToSize:CGSizeMake(oldImg_WID, oldImg_HEI)];

NSData*dJpeg =nil;

if(UIImagePNGRepresentation(newImg)==nil) {

dJpeg = UIImageJPEGRepresentation(newImg,0.5);

}else{

dJpeg = UIImagePNGRepresentation(newImg);

}

return[UIImageimageWithData:dJpeg];

}

#pragma mark - 压缩多张图片 自定义最大宽高

- (NSArray*)getJPEGImagerImgArr:(NSArray*)imageArrcompressibilityFactor:(CGFloat)compressibilityFactor{

NSMutableArray*newImgArr = [NSMutableArraynew];

for(inti =0; i

UIImage*newImg = [selfgetJPEGImagerImg:imageArr[i]compressibilityFactor:compressibilityFactor];

[newImgArraddObject:newImg];

}

returnnewImgArr;

}

#pragma mark - 根据宽高压缩图片

- (UIImage*)imageWithImage:(UIImage*)imagescaledToSize:(CGSize)newSize{

UIGraphicsBeginImageContext(newSize);

[imagedrawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

returnnewImage;

}