UIImage Category for efficient thumbnail gen

Clientcode.m

cell.imageView.image = [UIImage imageThumbnailNamed:@"example.jpg" width:20];

UIImage+Thumbnail.h

#import <UIKit/UIKit.h>

@interface UIImage (Thumbnail)


+ (UIImage *)imageThumbnailNamed:(NSString *)name width:(int)thumbWidth;

@end

UIImage+Thumbnail.m

#import <ImageIO/ImageIO.h>
#import "UIImage+Thumbnail.h"

@implementation UIImage (Thumbnail)

+ (UIImage *)imageThumbnailNamed:(NSString *)name width:(int)thumbWidth {

    NSString *fname = [[name lastPathComponent] stringByDeletingPathExtension];
    NSString *ext =  [name pathExtension];

    NSURL* url = [[NSBundle mainBundle] URLForResource:fname withExtension:ext];
    CGImageSourceRef src = CGImageSourceCreateWithURL((__bridge CFURLRef)url, NULL);
    CGFloat scale = [UIScreen mainScreen].scale;
    CGFloat w = thumbWidth*scale;
    
    NSDictionary* d =[NSDictionary dictionaryWithObjectsAndKeys:(id)kCFBooleanTrue, kCGImageSourceShouldAllowFloat, (id)kCFBooleanTrue, kCGImageSourceCreateThumbnailWithTransform, (id)kCFBooleanTrue, kCGImageSourceCreateThumbnailFromImageAlways, [NSNumber numberWithInt:(int)w], kCGImageSourceThumbnailMaxPixelSize, nil];
    CGImageRef imref =CGImageSourceCreateThumbnailAtIndex(src, 0, (__bridge CFDictionaryRef)d);
    
    return [UIImage imageWithCGImage:imref scale:scale orientation:UIImageOrientationUp];
    
}

@end