How to Multiple UIImages cropping and saving in a single loop - ios

Question

In my project is using maximum 60 images and One of my feature is needs to be an automatically crop all the 60 images in a given Ratio. I'm using the for loop for this implementation.
Inside the for loop contains crop and save the images. It was Implemented. But My app Meets crash in device because of Due to Memory pressure. Please Help Me
for (int ref=0; ref<[_selectedPhotosCollectionthumb count];ref++)
{
UIScrollView *scrollView=[[UIScrollView alloc] initWithFrame:CGRectMake(0,biManager.screenSize.height/2,biManager.screenSize.width,biManager.screenSize.height/2)];
[scrollView setDelegate:self];
[scrollView setBackgroundColor:[UIColor clearColor]];
[self addSubview:scrollView];
// scrollView.backgroundColor=[UIColor blueColor];
scrollView.userInteractionEnabled=YES;
scrollView.scrollEnabled=YES;
scrollView.tag=ref;
scrollView.hidden=YES;
[_scrollViews addObject:scrollView];
NSLog(#"%i",[_selectedPhotosCollection count]);
NSMutableArray *arrayCell=[_productCollectionsDict valueForKey:[_selectedPhotosCollection objectAtIndex:ref]];
int heightV=0;
for (int cellIndex=0;cellIndex<[arrayCell count];cellIndex++)
{
PrintCellView *cellObj=[arrayCell objectAtIndex:cellIndex];
if(cellObj.pCount>0)
{
PrintEditCellView *cell;
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
cell=[[PrintEditCellView alloc] initWithFrame:CGRectMake(0,heightV*100,biManager.screenSize.width,100)];
scrollView.contentSize=CGSizeMake(0,heightV*100+100);
cell.delegate=self;
}
else
{
cell=[[PrintEditCellView alloc] initWithFrame:CGRectMake(0,heightV*50,biManager.screenSize.width,50)];
scrollView.contentSize=CGSizeMake(0,heightV*50+50);
cell.delegate=self;
}
NSDate *now = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = #"hh:mm:ss";
[dateFormatter setTimeZone:[NSTimeZone systemTimeZone]];
NSLog(#"The Current Time is %#",[dateFormatter stringFromDate:now]);
// NSData *imageData=UIImageJPEGRepresentation(Thumbimage,1.0);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:[_selectedPhotosCollection objectAtIndex:ref]];
NSData *data = [[NSMutableData alloc] initWithContentsOfFile:path];
UIImage *image1=[[UIImage alloc]initWithData:data];
cell.productName.text=cellObj.productName.text;
UIImage * image=[self imageByCropping:image1 CropRatio:cell.productName.text];
NSLog(#"CROPPPP");
NSData *imageData= [[NSData alloc] initWithData:UIImageJPEGRepresentation(image,1.0)];
//
NSString* path1 = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:#"Prydex%i%#.jpg",cellIndex,[dateFormatter stringFromDate:now]]];
NSLog(#"pthhh:%#",path1);
[imageData writeToFile:path1 atomically:YES];
cell.editedImageURL=path1;
NSLog(#"%#,%i",cellObj.productName.text,cellObj.pCount);
[scrollView addSubview:cell];
[cell release];
heightV=heightV+1;
[dateFormatter release];
[image1 release];
// [imageData release];
// [image release];
}
}
//NSLog(#"Scroll Count %i",[_scrollViews count]);
for (UIScrollView *scrollView in _scrollViews)
{
if (scrollView.tag==0)
{
scrollView.hidden=NO;
}
else
{
scrollView.hidden=YES;
}
}
[SVProgressHUD dismiss];
}
Cropping Code
- (UIImage *)imageByCropping:(UIImage *)image CropRatio:(NSString*)ratio
{
CGSize size;
NSArray *array=[ratio componentsSeparatedByString:#"*"];
NSString *productWidth=[array objectAtIndex:0];
NSString *productHeight=[array objectAtIndex:1];
NSLog(#"SIZE:%#,%#",productWidth,productHeight);
NSLog(#"SIZE:%f,%f",image.size.width,image.size.height);
if (image.size.width/[productWidth intValue]>=230)
{
if (image.size.height/[productHeight intValue]>=230) {
size=CGSizeMake([productWidth intValue]*230,[productHeight intValue]*230);
NSLog(#"SIZE Inner:%i,%i",[productWidth intValue],[productHeight intValue]);
}
else if(image.size.width/[productWidth intValue]>=100)
{
if (image.size.height/[productHeight intValue]>=100)
{
size=CGSizeMake([productWidth intValue]*100,[productHeight intValue]*100);
NSLog(#"SIZE outer:%i,%i",[productWidth intValue],[productHeight intValue] );
}
}
}
else if(image.size.width/[productWidth intValue]>=100)
{
if (image.size.height/[productHeight intValue]>=100)
{
size=CGSizeMake([productWidth intValue]*100,[productHeight intValue]*100);
NSLog(#"SIZE outer:%i,%i",[productWidth intValue],[productHeight intValue] );
}
}
NSLog(#"crop---->%#",NSStringFromCGSize(size));
double x = (image.size.width - size.width) / 2.0;
double y = (image.size.height - size.height) / 2.0;
CGRect cropRect = CGRectMake(x, y, size.width, size.height);
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);
UIImage *cropped = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
return cropped;
}

Answer 1

The solution might be using recursion:
Create a method that takes an array of images you need to process. Inside the method check if array count is zero.
If it is empty you should return, possibly doing some callback to notify the application your image processing is done.
If the array is not empty, take the first image from the array, do all the processing, then remove the first object from the array and call the same method with the new array missing that element. The call should be kind of
[self performSelector:#selector(methodName:) withObject:imageArray];
All together should look something like this:
- (void)processImages:(NSArray *)images {
if(images.count < 1) {
[self performSelectorOnMainThread:#selector(imageProcessingDone) withObject:nil waitUntilDone:NO];
}
else {
UIImage *toProcess = images[0];
NSMutableArray *newArray = [images mutableCopy];
[newArray removeObjectAtIndex:0];
//do the processing
[self performSelector:#selector(processImages:) withObject:newArray];
}
}