|Title||Studies on the effect of MegaPixel sensor resolution on displayed image quality and relevant metrics|
|Chuang Hsin Hung|
This paper investigates camera phone image quality, namely the effect of sensor megapixel (MP) resolution on the perceived quality of images displayed at full size on high-quality desktop displays. For the purpose, we use images from simulated cameras with different sensor MP resolutions. We employ methods recommended in the IEEE 1858 Camera Phone Image Quality (CPIQ) standard, as well as other established psychophysical paradigms, to obtain subjective image quality ratings for systems with varying MP resolution from large numbers of observers. These are subsequently used to validate image quality metrics (IQMs) relating to sharpness and resolution, including those from the CPIQ standard. Further, we define acceptable levels of quality - when changing MP resolution - for mobile phone images in Subjective Quality Scale (SQS) units. Finally, we map SQS levels to categories obtained from star-rating experiments (commonly used to rate consumer experience). Our findings draw a relationship between the MP resolution of the camera sensor and the LCD device. The chosen metrics predict quality accurately, but only the metrics proposed by CPIQ return results in calibrated JNDs in quality. We close by discussing the appropriateness of star-rating experiments for the purpose of measuring subjective image quality and metric validation.
|Keywords||image quality, camera phone, resolution, sharpness, CPIQ|
|Conference||IS&T Electronic Imaging: Image Quality and System Performance XVII|
|Publisher||The Society of Imaging Science and Technology|
|Web address (URL)||http://www.imaging.org/site/IST/IST/Conferences/EI/EI_2020/Conference/C_IQSP.aspx|