Methods To Improve The Image Grayscale Resolution And Its Quality Evaluation

In biomedical imaging,the image quality determines the level of diagnosis and treatment,and grayscale resolution is an important parameter to measure image quality.Especially in the detection of breast tumors,increasing the grayscale level of the image helps to extract the edges of tumor tissue more accurately and improve the accuracy of clinical diagnosis.However,the current methods for improving image quality and quality assessment pay little attention to the grayscale resolution,basically based on spatial resolution.Therefore,based on the grayscale resolution of the image,this paper proposes a quality assessment metric and two methods of improving the grayscale resolution of the image,and completes the following main contents:(1)Frame accumulation technique is an effective means to improve the grayscale resolution of images,in order to evaluate the quality of the frame accumulated image,this paper proposes a metric,“mean signal-to-noise ratio”(MSNR).The images were acquired under a constant il umination signal.The mean image of enough images was regarded as the reference image.Several groups of averaged images by different frame numbers were regarded as the evaluated images and their MSNR were calculated.The experimental results show that,compared with other quality assessment methods,the MSNR metric is simpler,more effective,and more suitable for evaluating the quality of frame accumulated images,which provides a basis for the quality evaluation of frame accumulated images under the sawtooth-shaped-function(SSF)signal il umination.(2)In order to further improve the grayscale resolution of the image,from the perspective of changing the light intensity,an il umination method of selecting the appropriate range of SSF light intensity is proposed.By avoiding the portion of the weak light intensity and the strong light intensity near the camera saturation area,an appropriate range of il umination intensity is gotten,where the MSNR of image is higher.And through experiments,it is proved that using this range of light intensity il umination,the acquired image has higher grayscale resolution and better quality.(3)From the perspective of image processing,the image oversampling and downsampling techniques are used to prove the effectiveness of the method of obtaining high gray-scale resolution at the cost of a certain spatial resolution of image.The experimental results show that the image compression method further improves the grayscale resolution of the image,enriches the grayscale information of the image,and improves the accuracy and quality of the image.In the future research of breast tumor detection,using the quality assessment metric and the method of improving image grayscale resolution proposed in this paper can extract the edges of tumor tissue more accurately,which is conducive to the classification and analysis of tumor tissue and improve the accuracy of clinical diagnosis.