             self.plotLogGraph(samples, maximumValue: sampleMax, zeroValue: self.noiseFloor, imageHeight: heightInPixels) {
                 (image, selectedImage) in
                 DispatchQueue.main.async {
-                    self.image.image = image
+                    self.imageView.image = image
                     self.highlightedImage.image = selectedImage
                     self.cachedSampleRange = renderStartSamples ..< renderEndSamples
                     self.renderingInProgress = false

    }

    /// View for rendered waveform
    fileprivate let image: UIImageView = {
        let retval = UIImageView(frame: CGRect.zero)
        retval.contentMode = .scaleToFill
        return retval


    /// If the cached image is insufficient for the current frame
    fileprivate func cacheIsDirty() -> Bool {
        guard let image = imageView.image else { return true }
        
        if cachedSampleRange.count == 0 {
            return true
