How to rotate image by 90 degrees and save

Question

I want to take image from documents directory then rotate and reflect the changes to the same image file in documents directory.

I am getting image by using imagepath like this

[UIImage imageWithContentsOfFile:imgURL];

I want to rotate this image by 90 degrees and save at the same path with same image name.

Considering the state of the art in iOS, I don't know a way to save an image by 90 degrees. — , Nov 11 '13 at 06:38
http://stackoverflow.com/questions/1315251/how-to-rotate-a-uiimage-90-degrees — Arun, Nov 11 '13 at 06:43
Actually real question is,how do i make this change to original file? — Preetam Jadakar, Nov 11 '13 at 06:50

Raon · Accepted Answer · 2013-11-11T06:54:10.043

1

  UIImage *image = [UIImage imageWithContentsOfFile:imgURL];
    UIImage *newImage=[image imageRotatedByDegrees:90.0]; // i guess "image" is your orginal image
[[NSFileManager defaultManager] removeItemAtPath:imgURL];
    [UIImageJPEGRepresentation(newImage) writeToFile:imgURL atomically:YES];

edited Nov 11 '13 at 06:54

answered Nov 11 '13 at 06:48

Raon

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but how do i make this change to original file? – Preetam Jadakar Nov 11 '13 at 06:49
@preetam write the new file to disk. [UIImageJPEGRepresentation(image, 1.0) writeToFile:[self filePath:aName] atomically:YES] – sbarow Nov 11 '13 at 06:50
@sbarow: can I write by same name?does it overrides? – Preetam Jadakar Nov 11 '13 at 06:52
1

@preetam http://stackoverflow.com/questions/14280989/renaming-an-existing-file-with-obj-c – sbarow Nov 11 '13 at 06:53

score 1 · Answer 2 · answered Nov 11 '13 at 07:15

Try this code:

UIImageView *starimage=[[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile: imgURL]];
starimage.transform=CGAffineTransformMakeRotation(3.14159265/2 * -1); //For Left rotation

starimage.transform=CGAffineTransformMakeRotation(3.14159265/2 * 1); //For Right rotation

NSData *imagedata=UIImagePNGRepresentation(starimage.image);

//------Now writte image data to file --------

NSString *fileName = [NSString stringWithFormat:@"test.png"];

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *saveDirectory = [paths objectAtIndex:0];
NSString *saveFileName = fileName;
NSString *documentPath = [saveDirectory stringByAppendingPathComponent:saveFileName];
// [imagedata writeToFile:documentPath atomically:YES encoding:NSUTF8StringEncoding error:nil];
[imagedata writeToFile:documentPath atomically:YES];

How to rotate image by 90 degrees and save

2 Answers2