Subjective image fidelity metric based on bit allocation of the human visual system in the DCT domain

J. Malo, A.M. Pons and J.M. Artigas
Image and Vision Computing, Vol. 15, 7, pp 535-548 (1997)


Until now, subjective image distortion measures have partially used diverse empirical facts concerning human perception: non-linear perception of luminance, masking of the impairments by a highly textured surround, linear filtering by the threshold frequency response of the visual system, and non-linear post-filtering amplitude corrections in the frequency domain.

In this work, we develop a frequency and contrast dependent metric in the DCT domain using a fully non-linear and suprathreshold contrast perception model: the Information Allocation Function (IAF) of the visual system. It is derived from experimental data about frequency and contrast incremental thresholds and it is consistent with the reported noise adaptation of the visual system frequency response. Exhaustive psychophysical comparison with the results of other subjective metrics confirms that our model deals with a wider range of distortions more accurately than previously reported metrics. The developed metric can, therefore, be incorporated in the design of image coding algorithms as a closer approximation of human assessment of image quality.

Key Words: Subjective image fidelity. Non-linear perception model

References: 29

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