Question

I am building a simple app that allows the user to take photos that will be saved in the photo album. Because I expect users will be taking a lot of images of objects that look similar but not the same (for example, details of pieces of furniture in a house), I would like to add a small text caption on the image itself to describe the content of the image.

Not worrying about how the user will enter this text at the moment, can anyone give me some advice as to how I can add some text to an image taken with the UIImagePickerController?

Answer 1

1. Create a new graphics context.
2. Draw the image into the context.
3. Draw the text over it.
4. Create a new image from the context.

The code should be something like this:

UIGraphicsBeginImageContextWithOptions(sourceImage.size, YES, sourceImage.scale);
[sourceImage drawAtPoint:CGPointZero];

NSString *caption = @"Hello World";
UIFont *captionFont = [UIFont boldSystemFontOfSize:24.0];
[[UIColor whiteColor] setFill]; // or setStroke? I am not sure.
;

UIImage *resultImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();