image has too big height to display - ios

Question

Please, help me study objective-c!
My program takes a screenshot of whole UIWebView content, saves it, and supposed to display it.
It works fine, until it meets a very long page. Seems like the height of a page is an issue, since it displays 5 Mb screenshots just fine, as long as they are not too long (don't have to much height), however 1Mb but extremely long screenshots do not display in the UIImageView at all. It displays the UIImageView's background and that's it.
My code, attempts to resize the page to be maximum 2000 in height, and minimum 75% of the whole screen size. Aspect ratio is secondary. However, the image is still missing:
- (void)viewDidLoad
{
[super viewDidLoad];
CGFloat divider = 2;
CGFloat imageDisplayLimit = 2000;
CGFloat width = _image.size.width;
CGFloat height = _image.size.height;
//determine the leading parameter (just in case of a fat-S image)
if (width > imageDisplayLimit || height > imageDisplayLimit) {
if (width > height) {
divider = width / imageDisplayLimit;
} else {
divider = height / imageDisplayLimit;
}
}
//don't let it get too fat
CGFloat minimumWidth = self.view.frame.size.width / 1.5;
if (width / divider < minimumWidth) {
width = minimumWidth;
} else {
width /= divider;
}
//don't let it get too long
CGFloat minimumHeight = self.view.frame.size.height / 1.5;
if (height / divider < minimumHeight) {
height = minimumHeight;
} else {
height /= divider;
}
_imageView = [[UIImageView alloc] initWithImage:_image];
_imageView.frame = CGRectMake(0, 0, width, height);
//now just to make it obvious - red background
_imageView.backgroundColor = [UIColor redColor];
_imageView.frame = CGRectMake(0, 0, _image.size.width / divider, _image.size.height / divider);
_imageView.autoresizingMask = (UIViewAutoresizingFlexibleLeftMargin|UIViewAutoresizingFlexibleRightMargin);
_imageView.contentMode = UIViewContentModeScaleAspectFill;
[_scrollView addSubview:_imageView];
_scrollView.contentSize = _imageView.bounds.size;
_scrollView.delegate = self;
//just to make scroll visible during debug
_scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
...
At this point nothing shows, but the red background on a scrollable view.
I'm studying objective-c and don't know A LOT, but I was trying to find a solution for 2 days now. Please, save me!
My guess is aspect fill or fit doesn't do anything just because they don't actually change the image - just a display. What I really should be using (IMHO) is the UIGraphicsBeginImageContext. But I simply don't know how to make it shrink to max 2000 px. I am able to cut it by using
UIGraphicsBeginImageContext(someSizeWith2000Height)
[originalImage drawInRect:CGRectMake(resized_x, resized_y, resized_width, resized_height)];
UIImage* resized_image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
or something like that, but I don't wanna cut it - just shrink (or stretch if too short).
Any ideas? I've run out of those.

Answer 1

Well, since stackoverflow's system is so great, it drops questions between the desks and none can find them, I had to give up on this problem, and the only solution I could come up with is replace UIImageView with UIWebView as an image-displaying view. It makes the image displayed with TERRIBLE quality, but at least it is displayed.
Please, if anyone finds this question by chance and can help.... help! :)