Core Image for Fun and Profit

Over the last few months, I've been working on a project around better CoreImage filter documentation (https://cifilter.io). Using that as a framework, this talk goes through an overview of CIImage and CIFilter, how to use them in Swift, how we use CIFilter at PlanGrid, some tricky CoreImage gotchas. There will even be a demo or two about applying real CIFilters.

Transcript

1. Core Image for Fun and Profit Noah Gilmore @noahsark769 Swift Language User Group 3/27/2019
5. Two things - 207 powerful image processing filters (as of iOS 12) - Documentation is inaccessible/out of date
6. CIFilter.io
7. Fun Profit
8. Agenda - CIImage and CIFilter - Common and useful filters - CoreImage gotchas - Demo (compositing images)
9. Core Image
10. What is Core Image - : “Use built-in or custom filters to process still and video images.” Documentation
11. What is Core Image Documentation CIImage - : “Use built-in or custom filters to process still and video images.”
12. What is Core Image Documentation CIFilter - : “Use built-in or custom filters to process still and video images.”
13. What is CIImage - : “Not an image”
14. What is CIImage - : “Not an image” - A recipe for producing pixel data
15. What is CIImage - : “Not an image” - A recipe for producing pixel data, based on kernels and transforms - When you instantiate a CIImage, no pixel loading actually happens
16. What is CIImage CIImage CGImage UIImage CVPixelBuffer MTLTexture Data
17. What is CIFilter - Accepts 0 or more inputs via KVO - Images, ints, floats, vectors, colors, you name it
18. What is CIFilter - Accepts 0 or more inputs via KVO - Images, ints, floats, vectors, colors, you name it - Outputs one outputImage
19. What is CIFilter - Accepts 0 or more inputs via KVO - Images, ints, floats, vectors, colors, you name it - Outputs one outputImage - Can be applied to still images (CIImage) or video (AVVideoComposition)
20. CIFilter Example CIBoxBlur https://cifilter.io/#CIBoxBlur 100 inputImage inputRadius outputImage
21. CIFilter Example https://cifilter.io/#CIBoxBlur
22. Useful filters
23. Compositing operations CISourceInCompositing CISourceOutCompositing CISourceAtopCompositing CISourceOverCompositing https://cifilter.io/#CISourceInCompositing, https://cifilter.io/#CISourceOutCompositing, https://cifilter.io/#CISourceAtopCompositing, https://cifilter.io/#CISourceOverCompositing
24. Generators CIPDF417BarcodeGenerator CIAztecCodeGenerator CIQRCodeGenerator https://cifilter.io/#CIQRCodeGenerator, https://cifilter.io/#CIAztecCodeGenerator, https://cifilter.io/#CIPDF417BarcodeGenerator
25. Effects CISepiaTone CIThermal CIXRay CIComicEffect CICrystallize CIPointillize CIPixellate
26. Gotchas
27. Extent - The extent of a CIImage specifies its bounds (as a CGRect)
28. Extent - The extent of a CIImage specifies its bounds (as a CGRect) - Some CIImages have infinite extent - CIImage(color: CIColor.red)
29. Extent - The extent of a CIImage specifies its bounds (as a CGRect) - Some CIImages have infinite extent - CIImage(color: CIColor.red) - What happens if you set: - myImageView.image = UIImage(ciImage: CIImage(color: CIColor.red))
30. Extent - The extent of a CIImage specifies its bounds (as a CGRect) - Some CIImages have infinite extent - CIImage(color: CIColor.red) - What happens if you set: - myImageView.image = UIImage(ciImage: CIImage(color: CIColor.red)) - Use cropped(to:) to crop an infinite CIImage
31. UIImage and UIImageView - UIImage is backed by either a CGImage or a CIImage - myUIImage.ciImage and myUIImage.cgImage will be nil if their types do not back the image
32. UIImage and UIImageView - UIImage is backed by either a CGImage or a CIImage - myUIImage.ciImage and myUIImage.cgImage will be nil if their types do not back the image - UIImageView will render the image when it’s displayed - Main thread issues
33. UIImage and UIImageView
34. Processing time - Don’t depend on quick application of filters
35. Demo time
37. Thank you
38. Thank You - https://cifilter.io - https://github.com/noahsark769/CIFilter.io - https://twitter.com/noahsark769 - https://plangrid.com/careers