A new method for extracting visual saliency map for visual prosthesis / 国际生物医学工程杂志

ABSTRACT

Objective Salient regions may express the main content (salient objects) in an image or scene.Since the number of implanted electrodes for visual prosthesis is limited,only the low-resolution image is used.Extraction of the salient regions may help capture salient objects in the scenes of visual prosthesis.Methods Salient regions detected by Itti model,one of salient detection models,have some differences with human visual perceptions and its salient objects boundary are also unclear.The Itti model was optimized by removing the orientation and the color characteristics,and converting the RGB image in an image or scene into the HSI color space with three new feature components of hue,saturation and intensity.In saliency map,the ratio of the salient point area in salient objects regions and the total salient point area was defined as salient accuracy and computed,which was used to compare the effects of the two methods of extracting salient map.Results Compared with the Itti method for extracting saliency map,the salient accuracy of the improved method was increased by about 20％,and the time for detecting the same salient regions by our method was shorter by nearly 50％.Conclusions The proposed algorithm can be an alternative method to extract salient map from a complex image or scene for retinal prosthesis with higher salient accuracy and less running time.