Create Thumbnail from pdf file

- (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;
}

// Resize Thumbnail
- (UIImage *)image:(UIImage*)originalImage scaledToSize:(CGSize)size
{
    //avoid redundant drawing
    if (CGSizeEqualToSize(originalImage.size, size))
    {
        return originalImage;
    }
    
    //create drawing context
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
    
    //draw
    [originalImage drawInRect:CGRectMake(0.0f, 0.0f, size.width, size.height)];
    
    //capture resultant image
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    //return image
    return image;
}

 

How to Use

NSString *pdfpath = [documentsDirectory stringByAppendingPathComponent:[filePathsArray objectAtIndex:indexPath.row]];
NSURL* pdfFileUrl = [NSURL fileURLWithPath:pdfpath];
CGPDFDocumentRef pdf = CGPDFDocumentCreateWithURL((CFURLRef)pdfFileUrl);
UIImage *pdfthumb = [self imageFromPDFWithDocumentRef:pdf];

cell.imageView.image = [self image:pdfthumb scaledToSize:CGSizeMake(40, 40)];

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