Transform byte array(original image file in byte) to OpenCVMat
A transformer chain two FeatureTransformer together.
Distributerd ImageFrame, it keeps an rdd of ImageFeature
FeatureTransformer is a transformer that transform ImageFeature
Each ImageFeature keeps information about single image, it can include various status of an image, e.
ImageFrame wraps a set of ImageFeature
Transforms tensors that map inputKeys and targetKeys to sample
Local ImageFrame, keeps an array of ImageFeature
Transform OpenCVMat to float array, note that in this transformer, the mat is released
transform opencv mat to tensor