add image ops to operation mapper (#91)
add image ops to operation mapper (#91)


tensorflow/tfjs-converter,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs-converter,tensorflow/tfjs-converter,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs,tensorflow/tfjs-converter,tensorflow/tfjs,tensorflow/tfjs-converter,tensorflow/tfjs,tensorflow/tfjs