Methods for compressing shape data for a set of electronic designs include inputting a set of shape data, where the shape data represents a set of shapes for a device fabrication process. A convolutional autoencoder is used on the set of shape data, the convolutional autoencoder having a pre-determined set of convolution layers including a kernel size and filter size for each convolution layer. The set of shape data is encoded to compress the set of shape data, using the pre-determined set of convolution layers of the convolutional autoencoder, to create a set of encoded shape data. The set of shape data comprises an SEM image, and the encoded set of shape data identifies a mask defect.