Browsing by Author "Hsu, Shau-Wei"

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Evaluation of video quality by CWSSIM method
(2010-01-01)
Chen, Yu-Ta
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Hsu, Shau-Wei
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Pong, Bao-Jen
;
Mang Ou-Yang
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電控工程研究所
Several estimative factors of image quality have been developed for approaching the human perception objectively(1-3). We propose to take systematically distorted videos into the estimative factors and analyze the relationship between them. Several types of noise and noise weight were took into COSME standard video and verified the image quality estimative factors which were MSE (Mean Square Error). SSIM (Structural SIMilarity). CWSSIM (Complex Wavelet SSIM). PQR (Picture Quality Ratings) and DVQ (Digital Video Quality). The noise includes white noise, blur and luminance. etc. In the results, CWSSIM index has higher sensitivity at image structure and it could estimate the distorted videos which have the same noise type at the different levels. PQR is similar to CWSSIM, but the ratings of distribution were banded together; SSIM index divides the noise types into two groups and DVQ has linear relationship with MSE in the logarithmic scale.
Measurement of binocular disparity in polarized based stereoscopic display by using digital camera
(2013-06-01)
Chen, Yu-Ta
;
Hsu, Shau-Wei
;
Pong, Bao-Jen
;
Ou-Yang, Mang
;
Lee, Cheng-Chung
This work presents an image displacement measurement by using a box pattern and the edge spread function analysis in the polarized based stereoscopic displays. The measurement determines to identify three factors (i.e., box size, image displacement, and spatial frequency response (SFR)) from the box patterns. The polarized based stereoscopic displays might sacrifice pixels for producing 3D images, which might produce errors in the image displacement and then affect the depth perception indirectly. Based on the measurement, the errors can be quantified by using the three factors. Owing to the light leakage distorting the edge spread function to obtain an inferior SFR, exactly how light leakage affects the edge spread function can be resolved on the basis of the SFR results, especially at a frequency (1/display pixel) of 1.9 in the case of the horizontal displacement. Light leakage also induces the error of the box height in even and odd intervals of the vertical displacements more than 2pixels and 0.5pixels, respectively. The image displacement measurement provides a simple and comprehensive means of evaluating the optical characteristics, disparity, and sharpness of the stereoscopic displays, via the three factors.