- (UIImage*)compressImage:(UIImage*)image newWidth:(CGFloat)newImageWidth

{

if(!image)returnnil;

floatwidth = newImageWidth;

floatheight = image.size.height/(image.size.width/width);

//创建一个bitmap的context

//并把它设置成为当前正在使用的context

UIGraphicsBeginImageContext(CGSizeMake(width, height));

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

//从当前context中创建一个改变大小后的图片

UIImage*newImage =UIGraphicsGetImageFromCurrentImageContext();

//使当前的context出堆栈

UIGraphicsEndImageContext();

returnnewImage;

}

- (NSData*)compressOriginalImage:(UIImage*)image toMaxDataSizeKBytes:(CGFloat)size{

NSData* data =UIImageJPEGRepresentation(image,1.0);

CGFloatdataKBytes = data.length/1024.0;

CGFloatmaxQuality =0.9f;

CGFloatlastData = dataKBytes;

while(dataKBytes > size && maxQuality >0.1f) {

maxQuality = maxQuality -0.1f;

data =UIImageJPEGRepresentation(image, maxQuality);

dataKBytes = data.length/1024.0;

if(lastData == dataKBytes) {

break;

}else{

lastData = dataKBytes;

}

}

returndata;

}