GPUImageVideoCamera Live Preview with Custom LUT using GPUImagePicture - ios

Question

I'm using Swift 3 with GPUImage. I have a LUT image file named: lut_lookup.png I have successfully used this with GPUImage on a still image and it applies and displays the result using the LUT filter.
I'm now trying to apply the same LUT filter to the live camera view, but I cannot seem to get it to work. It essentially doesn't even display the camera.
I've supplied my code below, any help would be greatly appreciated. It's probably something simple I've missed/done wrong, but I can't seem to spot it.
import UIKit
import GPUImage
class LiveCameraVC: UIViewController
{
// MARK: - Variables
let videoCamera: GPUImageVideoCamera? = {
if let videoCamera = GPUImageVideoCamera(sessionPreset: AVCaptureSessionPreset640x480, cameraPosition: .back) {
videoCamera.outputImageOrientation = .portrait
videoCamera.horizontallyMirrorFrontFacingCamera = false
videoCamera.horizontallyMirrorRearFacingCamera = false
return videoCamera
} else {
print("GPUImageVideoCamera Nil")
return nil
}
}()
let filter: GPUImageLookupFilter = {
let filter = GPUImageLookupFilter()
filter.intensity = 1.0
return filter
}()
// MARK: - UI
let modifiedImageView: GPUImageView = {
let imageView = GPUImageView.newAutoLayout()
imageView.fillMode = kGPUImageFillModePreserveAspectRatioAndFill;
imageView.isUserInteractionEnabled = true
return imageView
}()
// MARK: - Life Cycle
override func viewDidLoad() {
super.viewDidLoad()
let tapGesture:UITapGestureRecognizer = UITapGestureRecognizer().bk_init { [unowned self] (sender:UIGestureRecognizer?, state:UIGestureRecognizerState, location:CGPoint) in
print("Tapped")
self.performLut()
} as! UITapGestureRecognizer
modifiedImageView.addGestureRecognizer(tapGesture)
}
override func loadView() {
super.loadView()
self.view.addSubview(modifiedImageView)
modifiedImageView.autoPinEdgesToSuperviewEdges()
}
// MARK: - Private
private func performLut() {
print("performLut")
if let videoCamera = videoCamera {
if let lookupImageSource = GPUImagePicture(image: UIImage(named:"lut_lookup")) {
videoCamera.addTarget(filter, atTextureLocation: 0)
lookupImageSource.addTarget(filter, atTextureLocation: 1)
filter.addTarget(modifiedImageView)
videoCamera.startCapture()
} else {
print("videoCamera Nil")
}
} else {
print("GPUImageVideoCamera Nil")
}
}
}
Thanks

Answer 1

Solved it. I changed the code to this:
let imagePicture: GPUImagePicture? = {
if let imagePicture = GPUImagePicture(image: UIImage(named:"lut_lookup")) {
return imagePicture
} else {
print("GPUImagePicture Nil")
return nil
}
}()
private func performLut() {
if let videoCamera = videoCamera {
if let imagePicture = imagePicture {
videoCamera.addTarget(filter)
imagePicture.addTarget(filter)
imagePicture.processImage()
filter.addTarget(modifiedImageView)
videoCamera.startCapture()
}
}
}
Hopefully that helps someone!