  We report an algorithm, based on quantum optics formulation, where a coherent
state is used as the elementary quantum resource for the image representation.
We provide an architecture with constituent optical elements in linear order
with respect to the image resolution. The obtained phase-distributed multimode
coherent state is fed into an image retrieval scheme and we identify the
appropriate laser intensity parameter for similarity measurement. The use of
the principle of quantum superposition in the similarity measurement protocol
enables us to encode multiple input images. We demonstrate the viability of the
protocol through an objective quality assessment of images by adding
consecutive layers of noises. The results are in good agreement with the
expected outcome. The image distortion-sensitivity analysis of the metric
establishes the further merit of the model. Our quantum algorithm has wider
applicability also in supervised machine learning tasks.
