Fabulous Image Processing in Swift

Hi, I use your library to resize my images in my tableview and I noticed that the memory keeps increasing in my app when I use instruments. It shows your library and I checked out your code and I noticed that theres not memory management handling in your closures. It shows that on line 598 on the Toucan class reaching 200+mb's in the closure. Do you mind if I make a pull request and do a fix on it? I'm using your library for a production app

My app keeps crashing at this point when I try to resize an image and add a corner radius mask:

The crash occurs at this point:

        static func drawImageWithClosure(size size: CGSize!, closure: (size: CGSize, context: CGContext) -> ()) -> UIImage {
            UIGraphicsBeginImageContextWithOptions(size, false, 0)
            closure(size: size, context: UIGraphicsGetCurrentContext()!)
            let image : UIImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            return image
        }

UIGraphicsGetCurrentContext()! ==> fatal error: unexpectedly found nil while unwrapping an Optional value

Not sure what the desired way to resolve this would be:

• The current podspec could be updated, with the spec.swift_version property set to '4.0'
• Wait until Swift 4.2 has been released fully and migrate Toucan accordingly.

In either case, setting the swift_version in the podspec would be a good idea to avoid this sort of thing in the future.

Note that the migrations for Toucan are (so far) very simple, just several instances of

UIImageOrientation has been renamed to UIImage.Orientation.

I have the same code which I use on iPad mini 1 and iPhone 6. The code takes photo by camera and then applies resizeByScaling:CGSizeMake(128, 128).

For iPad mini 1: it correctly resizes the image to 128x128. On iPhone 6, it is 256x256.

I think there is something wrong with the function. Perhaps it doesn't factor in retina level????

I am getting an exception when trying to resize the attached image (I hope the upload won't change the metadata)

Toucan.swift: 549 in Util.CGImageWithCorrectOrientation

: CGBitmapContextCreate: invalid data bytes/row: should be at least 4000 for 8 integer bits/component, 3 components, kCGImageAlphaNoneSkipLast

I think this is the same issue related to orientation: http://stackoverflow.com/a/11958833

We've recently had some crashes in our app due to the overuse of force unwrapped optionals in Toucan, so we've created our own fork to avoid them. And maybe it is also useful for others, so here you have this PR 😄

Basically what this PR does is just return an "empty" UIImage whenever something in the processing goes wrong.

I found that Toucan framework is not in zip file,so I tried to build and archive the Toucan project. Finally I got a Toucan.framework,but I found the header file just include:

#import <UIKit/UIKit.h>

//! Project version number for Toucan.
FOUNDATION_EXPORT double ToucanVersionNumber;

//! Project version string for Toucan.
FOUNDATION_EXPORT const unsigned char ToucanVersionString[];

Is anything I did wrong?

It looks like the image dimensions are swapped for left or right orientated images. I get stretched/scaled images after calling resizeImage when the image orientation is left, left mirrored, right, or right mirrored (for example, images from the device camera in portrait orientation). This seemed to fix the issue.

If we could get another v3 release as well, that would be great. Here are my changes for v3.

See https://developer.apple.com/library/content/qa/qa1964/_index.html#//apple_ref/doc/uid/DTS40017675 and https://github.com/Carthage/Carthage/pull/2057

I got this error when i select image captured by front camera.

let myImage = Toucan.init(image: images[0]).image

This is the error message:

UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
Dec 27 22:56:42  mask It[469] <Error>: CGBitmapContextCreate: invalid data bytes/row: should be at least 1920 for 8 integer bits/component, 3 components, kCGImageAlphaNoneSkipFirst.
fatal error: unexpectedly found nil while unwrapping an Optional value

When using resize and crop mode, it appears to crop the image from the middle. How can we crop from the top left corner? For example, if I have a UIImageView that is 400 x 200 and I want the image to be 400 width but crop anything over 200 high so just the top 200 pixels are visible, how can I do that?

Do you have any best practices/guide for using the API in a way that doesn't block the main thread?

let roundImage = Toucan(image: image).maskWithEllipse(borderWidth: 3.0, borderColor: UIColor.white).image

Especially when used in a TableView with lots of rounded images causes quite a bit of main thread activity.

The following code takes the upper bound of 170.6666 (which is 171) when UIScreen.main.scale is 3.0

let size = 512 / UIScreen.main.scale
let image = Toucan(image: item.image!).resize(CGSize(width: size, height: size), fitMode: Toucan.Resize.FitMode.clip).image!

It should have been resized the image according to the float in size. Not the upper bound of it.

We currently expire crashes in our app, which we "fixed" by removing force unwraps and adding logging to get more insights.

Crashlog

Crashed: com.apple.root.user-interactive-qos
0  Rabbit                         0x104977fc4 specialized static Toucan.Util.CGImageWithCorrectOrientation(UIImage) -> CGImage (Toucan.swift:571)
1  Rabbit                         0x10497871c specialized static Toucan.Resize.resizeImage(UIImage, size : CGSize, fitMode : Toucan.Resize.FitMode) -> UIImage? (Toucan.swift)
2  Rabbit                         0x1049c9100 specialized ThumbnailGenerator.generate(for : UIImage) -> [ThumbnailGenerator.GeneratedThumbnail] (ThumbnailGenerator.swift:61)
3  Rabbit                         0x1049fa134 specialized ContentMetadataFetcher.(generateVisualPreviews(for : Content, image : UIImage, storageController : LocalStorageController, completionHandler : ([VisualPreview]) -> ()) -> ()).(closure #2).(closure #1) (ContentMetadataFetcher+Thumbnails.swift:73)
4  Rabbit                         0x1049fa08c partial apply for ContentMetadataFetcher.(generateVisualPreviews(for : Content, image : UIImage, storageController : LocalStorageController, completionHandler : ([VisualPreview]) -> ()) -> ()).(closure #2).(closure #1) (ContentMetadataFetcher+Thumbnails.swift)
5  Rabbit                         0x10493db00 thunk (ContentCreationController.swift)
6  libdispatch.dylib              0x1851a6a54 _dispatch_call_block_and_release + 24
7  libdispatch.dylib              0x1851a6a14 _dispatch_client_callout + 16
8  libdispatch.dylib              0x1851b3ea4 _dispatch_root_queue_drain + 1032
9  libdispatch.dylib              0x1851b3a38 _dispatch_worker_thread3 + 120
10 libsystem_pthread.dylib        0x18544f06c _pthread_wqthread + 1268
11 libsystem_pthread.dylib        0x18544eb6c start_wqthread + 4

Device and system information

iOS 10 and iOS 11 iPad and iPhone

Known stats from logging

The crash is happening on this line which force unwraps the CGContext. It seems that scenarios exist in which the created context is nil.

After adding a guard and logging in the return statement, we've seen logs like this:

Error Domain=Toucan Code=-3 "width: 3840 height: 5760 bitsPerComponent: 8 bitmapInfo: 5" UserInfo={NSLocalizedDescription=width: 3840 height: 5760 bitsPerComponent: 8 bitmapInfo: 5}

Error Domain=Toucan Code=-3 "width: 120 height: 160 bitsPerComponent: 8 bitmapInfo: 0" UserInfo={NSLocalizedDescription=width: 120 height: 160 bitsPerComponent: 8 bitmapInfo: 0}

I've tried to reproduce the crash by hardcoding these values, but that didn't reproduce the crash. I've also made sure that the cgImage and Colorspace are non nil:

guard let cgImage = image.cgImage else {
    throw NSError(domain: "Toucan", code: -1, userInfo: [NSLocalizedDescriptionKey: "CGImage is nil"])
}

guard let colorSpace = cgImage.colorSpace else {
    throw NSError(domain: "Toucan", code: -2, userInfo: [NSLocalizedDescriptionKey: "Color space is nil"])
}

We've never seen these being logged.

Next steps

We for now prevented this crash from happening again by adding guards and throws instead of force unwrapping. It would be great if we can find the cause of this crash and fix it instead.

Hello,

We're using toucan in our app to resize product images using FitMode.crop. This fit mode produce really bad quality image even though the cropped image would maintain same aspect ratio as the original image.

Resize code in UIImageExtension:

Toucan(image: self).resize(CGSize(width: 345, height: 519), fitMode: Toucan.Resize.FitMode.crop).image!

I couldn't find any reason why this is happening. Please help.