Feature Extraction Image Targets

Vuforia SDK Version: Vuforia Engine v7.5.26 - Description with steps to reproduce: We get a lot of jittering augmentations lately (this happens since start of the year) even if we are using the same techniques to "optimize" (slightly increase of contrast and exposure for better edge detection) the images before putting them into the target manager for feature extraction and we are working with very similar kind of images as before too. The target manager show 5/5 stars and there are a lot of "good features" (based on your definition of good feature points in the documentation). It also seems to affect only newly added images. Already existing image targets perform much better but as soon as i remove a "good performing" old image target and immediately add it again, it performs much worse than before. Maybe i'm just crazy but it kinda feels like something changed in your feature extraction mechanism in the image target manager. - Development OS (Mac OS X, Windows, Linux): Mac OS X - Mobile OS and Version: iOS 12.1.2 (16C101) - Mobile Device Manufacturer and Model name: iPhone 6s - Do the Vuforia Sample Applications show the same behavior?: