Memristor bridge-based low pass filter for image processing

AbstractIn cryogenic electron microscopy (cryo-EM) of radiation-sensitive biological samples, both the signal-to-noise ratio (SNR) and the contrast of images are critically important in the image processing pipeline. Classic methods improve low-frequency image contrast experimentally, by imaging with high defocus, or computationally, by applying various types of low-pass filter. These contrast improvements typically come at the expense of high-frequency SNR, which is suppressed by high-defocus imaging and removed by low pass filtration. Here, we demonstrate that a convolutional neural network (CNN) denoising algorithm can be used to significantly enhance SNR and generate contrast in cryo-EM images. We provide a quantitative evaluation of bias introduced by the denoising procedure and its influences on image processing and three-dimensional reconstructions. Our study suggests that besides enhancing the visual contrast of cryo-EM images, the enhanced SNR of denoised images may facilitate better outcomes in the other parts of the image processing pipeline, such as classification and 3D alignment. Overall, our results provide a ground of using denoising CNNs in the cryo-EM image processing pipeline.

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Window Memoization In Software As Applied To Image Processing Algorithms

10.32920/ryerson.14654973.v1 ◽

2021 ◽

Author(s):

Tahir Jaffer

Keyword(s):

Image Processing ◽

Lower Bound ◽

Detection Algorithm ◽

Corner Detection ◽

Image Processing Algorithm ◽

Pass Filter ◽

Pixel Intensity ◽

Low Pass Filter ◽

Low Pass ◽

Speed Up

A new local image processing algorithm, the Tahir algorithm, is an adaptation to the standard low-pass filter. Its design is for images that have the spectrum of pixel intensity concentrated at the lower end of the intensity spectrum. Window memoization is a specialization of memoization. Memoization is a technique to reduce computational redundancy by skipping redundant calculations and storing results in memory. An adaptation for window memozation is developed based on improved symbol generation and a new eviction policy. On implementation, the mean lower-bound speed-up achieved was between 0.32 (slowdown of approximately 3) and 3.70 with a peak of 4.86. Lower-bound speed-up is established by accounting for the time to create and delete the cache. Window memoization was applied to: the convolution technique, Trajkovic corner detection algorithm and the Tahir algorithm. Window memoization can be evaluated by calculating both the speed-up achieved and the error introduced to the output image.

Download Full-text

Window Memoization In Software As Applied To Image Processing Algorithms

10.32920/ryerson.14654973 ◽

2021 ◽

Author(s):

Tahir Jaffer

Keyword(s):

Image Processing ◽

Lower Bound ◽

Detection Algorithm ◽

Corner Detection ◽

Image Processing Algorithm ◽

Pass Filter ◽

Pixel Intensity ◽

Low Pass Filter ◽

Low Pass ◽

Speed Up

A new local image processing algorithm, the Tahir algorithm, is an adaptation to the standard low-pass filter. Its design is for images that have the spectrum of pixel intensity concentrated at the lower end of the intensity spectrum. Window memoization is a specialization of memoization. Memoization is a technique to reduce computational redundancy by skipping redundant calculations and storing results in memory. An adaptation for window memozation is developed based on improved symbol generation and a new eviction policy. On implementation, the mean lower-bound speed-up achieved was between 0.32 (slowdown of approximately 3) and 3.70 with a peak of 4.86. Lower-bound speed-up is established by accounting for the time to create and delete the cache. Window memoization was applied to: the convolution technique, Trajkovic corner detection algorithm and the Tahir algorithm. Window memoization can be evaluated by calculating both the speed-up achieved and the error introduced to the output image.

Download Full-text