Research On Multi-focus Image Fusion Technology Based On Spatial Domain

Multi-focus image fusion technology adopts the method of image processing,so that under the same imaging conditions,objects at different focus positions can be clearly displayed in the same image.This technology overcomes the limitation of the limited focusing range of optical lens,and has been applied to the system of ultra-depth of field microscope,which has extensive application value in medicine and other fields.The image fusion method based on spatial domain is to fuse directly in the image pixel space and fully retain the pixel information in the source image.However,it is difficult to integrate the source information completely into the fusion image,and it is also susceptible to the interference of the surrounding environment.In order to solve the existing problems in this technology,this paper completes the multi-focus image fusion based on image segmentation.The main contents are as follows:(1)The multi-focus image fusion method based on image segmentation is studied,and the definition evaluation method based on wavelet transform combined with optimization and the fusion rule of gradual segmentation are designed.The fusion results of three sets of multi-focus sequence images show that the fusion effect of this method is better than the traditional fusion method in subjective evaluation and objective evaluation,and the obtained fusion images have more details,and effectively reduce the "block effect" of the fusion images.(2)The principle of sharpness evaluation method applicable to image fusion technology is studied,and various image sharpness evaluation methods are compared and analyzed.The wavelet transform based sharpness evaluation method is selected for optimization.Firstly,the wavelet coefficient amplitude of the signal and noise changes inversely with the increase of the scale,and the product of the high frequency components of adjacent scales is taken to effectively suppress the noise influence.Then,in order to fully consider the different proportion of different high frequency components,the weight factor is defined for the texture analysis of the image.The evaluation results of multi-focus image sharpness show that this method has better single-peak,unbiased,sensitivity and anti-noise performance than other methods,and can judge image sharpness results more accurately.(3)A method for measuring the depth of field of a microscope is designed based on the definition discrimination method.Starting from the definition of depth of field,the clear range of system imaging was found by measuring the sharpness of images at different focus positions,and the depth of field results were obtained.The experimental results of three groups of microscope systems show that the measurement scheme was feasible.