ios 调整图像大小 Objective-C
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Resizing Images Objective-C
提问by chrisw
I'm trying to downscale an image in Objective-C taken with the iPhone 4 and above so I can send it to the server as quickly as possible. At the moment the image at full size is taking ages.
我正在尝试缩小使用 iPhone 4 及更高版本拍摄的 Objective-C 图像，以便我可以尽快将其发送到服务器。目前，全尺寸图像需要很长时间。
The current of downsizing I am trying is:
我正在尝试的缩小规模的当前是：
CGSize imageSize;
imageSize = CGSizeMake(484, 888);
UIImage *img = [UIImage imageWithContentsOfFile:path];
UIGraphicsBeginImageContext( imageSize );
[img drawInRect:CGRectMake(0,0,imageSize.width,imageSize.height)];
UIImage* realfrontImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
NSData *frontImageData = UIImageJPEGRepresentation(realfrontImage, 1.0);
This gives me an image of 320x460 how do I get it the size I wanted 484x888.
这给了我一个 320x460 的图像，我如何得到我想要的 484x888 的大小。
回答by Anshuk Garg
-(UIImage*)imageWithImage:(UIImage*)image scaledToSize:(CGSize)newSize {
UIGraphicsBeginImageContext(newSize);
[image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
use this method to scale down your images.
使用此方法缩小图像。
回答by Nitin
// call this function with your resize ratio...
// 使用您的调整大小比率调用此函数...
-(UIImage*)scaleByRatio:(float) scaleRatio
{
CGSize scaledSize = CGSizeMake(self.size.width * scaleRatio, self.size.height * scaleRatio);
CGColorSpaceRef colorSpace;
int bitmapBytesPerRow;
bitmapBytesPerRow = (size.width * 4);
//The output context.
UIGraphicsBeginImageContext(scaledSize);
CGContextRef context = context = CGBitmapContextCreate (NULL,
scaledSize .width,
scaledSize .height,
8, // bits per component
bitmapBytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast);
//Percent (101%)
#define SCALE_OVER_A_BIT 1.01
//Scale.
CGContextScaleCTM(context, scaleRatio * SCALE_OVER_A_BIT, scaleRatio * SCALE_OVER_A_BIT);
[self drawAtPoint:CGPointZero];
//End?
UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return scaledImage;
}
Hope, this will help you...
希望能帮到你...
回答by Paul Peelen
Maybe this post helps you out: How to resize the image programmatically in objective-c in iphone
也许这篇文章可以帮到你：How to resize the image in Objective-c in iphone
Beware... you are doing this in Objective-C, ... not XCode. XCode is the application you develop Objective-c within. Just like Netbeans or Eclipse is commonly used for Java and PHP.
当心......你是在Objective-C中这样做的，......不是XCode。XCode 是您在其中开发 Objective-c 的应用程序。就像 Netbeans 或 Eclipse 通常用于 Java 和 PHP。
