Boost productivity on iphone while rendering pdf

Question

I have a UITableView and in each cell a UIImage created from pdf is displayed. But now the performance is very poor. Here is my code that I use to create a UIImage from a PDF.

Creating CGPDFDocumentRef and UIImageView (in cellForRowAtIndexPath method):

...    
CFURLRef pdfURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), (CFStringRef)formula.icon, NULL, NULL);
CGPDFDocumentRef documentRef = CGPDFDocumentCreateWithURL((CFURLRef)pdfURL);
CFRelease(pdfURL);
UIImageView *imageView = [[UIImageView alloc] initWithImage:[self imageFromPDFWithDocumentRef:documentRef]];
...

Create UIImage:

- (UIImage *)imageFromPDFWithDocumentRef:(CGPDFDocumentRef)documentRef {
    CGPDFPageRef pageRef = CGPDFDocumentGetPage(documentRef, 1);
    CGRect pageRect = CGPDFPageGetBoxRect(pageRef, kCGPDFCropBox);

    UIGraphicsBeginImageContext(pageRect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(context, CGRectGetMinX(pageRect),CGRectGetMaxY(pageRect));
    CGContextScaleCTM(context, 1, -1);  
    CGContextTranslateCTM(context, -(pageRect.origin.x), -(pageRect.origin.y));
    CGContextDrawPDFPage(context, pageRef);

    UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return finalImage;
} 

What can I do to increase speed and keep memory lower?

Answer 1

Creating a PDF image for each cell at runtime seems like a huge performance hit.

UIImages UITableView . , , .

, , "" " ".