Fredrik_T:

I only have two classes. So maybe place all other objects in an “other” class?


Please check:
  
    
    
    How can I specialize my model for precision, and make it default to an output if it is not certain enough to sacrifice accuracy? General Discussion
  
  
    I think that generally it is hard to handle a “default/none/other/garbage” dedicated class. 
I suppose that you could start to think about OOD that itself it is not an easy job also in Deep Learning. 
But you could start to take an overview in:
  


Generalized Out-of-Distribution Detection: A Survey:

Out-of-distribution (OOD) detection is critical to ensuring the reliability and safety of machine learning systems. For instance, in autonomous driving, we would like the driving system to issue an alert and hand over the control to humans when it detects unusual scenes or objects that it has never seen before and cannot make a safe decision. This problem first emerged in 2017 and since then has received increasing attention from the research community, leading to a plethora of methods developed, ranging from classification-based to density-based to distance-based ones. Meanwhile, several other problems are closely related to OOD detection in terms of motivation and methodology. These include anomaly detection (AD), novelty detection (ND), open set recognition (OSR), and outlier detection (OD). Despite having different definitions and problem settings, these problems often confuse readers and practitioners, and as a result, some existing studies misuse terms. In this survey, we first present a generic framework called generalized OOD detection, which encompasses the five aforementioned problems, i.e., AD, ND, OSR, OOD detection, and OD. Under our framework, these five problems can be seen as special cases or sub-tasks, and are easier to distinguish. Then, we conduct a thorough review of each of the five areas by summarizing their recent technical developments. We conclude this survey with open challenges and potential research directions.