Images being downloaded on my iphone app are being pixelated - iPhone SDK

Has anyone ever ran into the problem where images being downloaded are slightly pixelated. The only thing they have in common with each other is they are being resized using this function:

-(UIImage *)imageWithImage:(UIImage *)image CovertToSize:(CGRect)rect {
    CGSize size = CGSizeMake(rect.size.width, rect.size.height);
    UIGraphicsBeginImageContext(size);
    [image drawInRect:rect];
    UIImage *destImage = UIGraphicsGetImageFromCurrentImageConte开发者_StackOverflow中文版xt();    
    UIGraphicsEndImageContext();
    return destImage;
}

These images are jpegs. Has anyone ever heard of this or knows of solution?