  Current algorithms and architecture can create excellent DNN classifier
models from example data. In general, larger training datasets result in better
model estimations, which improve test performance. Existing methods for
predicting generalization performance are based on hold-out test examples. To
the best of our knowledge, at present no method exists that can estimate the
quality of a trained DNN classifier without test data. In this paper, we show
that the quality of a trained DNN classifier can be assessed without any
example data. We consider DNNs to be composed of a feature extractor and a
feature classifier; the feature extractor's output is fed to the classifier.
The proposed method iteratively creates class prototypes in the input space for
each class by minimizing a cross-entropy loss function at the output of the
network. We use these prototypes and their feature relationships to reveal the
quality of the classifier. We have developed two metrics: one using the
features of the prototypes and the other using adversarial examples
corresponding to each prototype. Empirical evaluations show that accuracy
obtained from test examples is directly proportional to quality measures
obtained from the proposed metrics. We report our observations for ResNet18
with Tiny ImageNet, CIFAR100, and CIFAR10 datasets. The proposed metrics can be
used to compare performances of two or more classifiers without test examples.
