deconwolf v0.4.3

deconwolf[^9] is a software for 3-D deconvolution of fluorescent wide-field images:

• The deconvolved images shows very mild boundary effects which means that relatively small regions of interest can be used.
• RAM usage can be reduced at the cost of slightly longer computation times by tiling. That makes it possible to deconvolve large images on small machines.
• Critical parts run on separate threads (as many as you would like). However, for maximal throughput (and if you have enough RAM), run several instances of dw in parallel.
• It is shipped with program to generate Point Spread Functions (PSFs) according to the Born and Wolf model. Our program is the only one we know of that actually integrate the PSF over each pixel.
• The programs are developed under Linux but can be compiled on Mac and Windows as well.
• Fully open source. And we embrace contributions and suggestions.

Deconwolf does not:

• Have a full-featured Graphical User Interface (GUI), however, if you like to click buttons there is a limited GUI.
• Show your images, for that, try ImageJ
• Diagnose your imaging system and correct for typical CMOS or CCD artifacts.
• Estimate your PSF based on real images.
• Tell you how many iterations that you should use although there are three ways to make it stop i) after a fixed number of iterations ii) when the progress is slow, or iii) at a fixed difference between the input image and the current guess (convolved with the PSF).
• If you miss one or more of these features, or just want something else, there is an (incomplete) list of alternative software.

Except for this README.me there is also a short USAGE.md, a CHANGELOG.md and a TODO.md.

After building and installing you will find two binaries:

• dw -- for deconvolution, man page
• dw_bw -- to create PSFs using the Born-Wolf model man page

At the moment we don't provide pre-built packages. You will have to build deconwolf from the source code, instructions follows below.

Method

The deconvolution algorithm is based on the Richardson-Lucy (RL) method [^2][^3]. The scaled heavy ball (SHB) [^4] is used for acceleration, i.e. to do more work per iteration. Compared to the "Biggs" acceleration, it use less memory, it also has a proven convergence without any modifications to the algorithm.

The default boundary handling method is based on [^1] , although extended to 3D. In our experiments it cause the least artifacts close to the image borders, especially important in the axial direction. To disable boundary handling, i.e. use periodic deconvolution, the option --periodic can be used.

The PSF calculations in dw_bw implements the "Born and Wolf" model [^5] which is also decribed well in [^6]. It is possible to speed up the calculations using the method from [^7] using the --li argument. At some point (after some more testing) it might become the default method. An important difference to the PSFGenerator is that each pixel in the PSF is integrated full, rather than just using one sample at the pixel centre. This modification gives measureable improvements, especially when the pixel size to resolution limit is low. dw psf also contains a few other PSF models which eventually will be documented as well.

For GPU calculations dw use VkFFT [^8] via OpenCL. Until version 0.3.6 libclfft2 was used for this purpose. Since OpenCL is vendor neutral, this option should work for all major GPU brands. On the CPU side FFTW is used, although it can of course be swapped with API compatible alternatives like MKL.

Build and install

Deconwolf runs on 64-bit machines with, both aarch64 and x86_64, and require no special hardware. For some platforms there are pre-compiled binaries available, see releases.

To compile and install deconwolf should take less than a minute on a Linux machine but might be more cumbersome on MacOS and Windows. For platform specific build instructions, see INSTALL.md. We hope to provide pre-compiled binaries in the future.

Dependencies

Deconwolf uses:

• FFTW for Fourier Transforms. Or alternatively Intel MKL.
• libtiff to read and write TIFF files.
• GNU Scientific Library for integration and special functions.
• OpenMP for automatic parallelization of code, used in dw.

If these libraries are available for your platform, chances are that deconwolf can be built as well.

To enable GPU acceleration, deconwolf also requires a GPU and OpenCL drivers installed.

Performance hints

The performance depends on the system and the image size. Except for some initialization (read images, padding, cropping ... ) and writing the output, the time is linear with the number of iterations.

Here is a table with performance figures for some real images. Run on a system with: a 4-core Intel i7-6700K CPU, 64 GB RAM, NVIDIA GeForce RTX 3090, using the --gpu flag and 50 iterations (--iter 50).

Running only on the CPU the throughput drops drastically on this machine, having only 4 cores:

Yes, deconvolution is time consuming without a GPU :(

Below there will be some hints on the performance relative to other software. For that purpose synthetic data will be used where periodic boundary conditions (--periodic) can be used. dw should not try to crop the PSF (which is usually done automatically to save some memory/gain some speed) in this case, hence the flag --xyfactor 0 is added as well.

Benchmarking is performed on the microtubules image using the accompanying PSF. Please note that it does not simulate "real" wide field data very well since it is created by periodic convolution.

System: Ubuntu 22.04.4 LTS, AMD Ryzen 7 3700X 8-Core Processor, 64 GB RAM, 12 GB RX 6700 XT GPU. Iterations: 115.

Notes:

• sys-mem is measured by parsing the VmPeak value from /proc/pid/status. In the case of DeconvolutionLab2 the values does not necessarily reflect the required memory since it is written in Java which is garbage collected. For MATLAB/deconvlucy the memory includes the full MATLAB environment.

• self-mem is the memory usage reported by the software if available.

• DeconlutionLab2 use vanilla RL, i.e. without any acceleration which means that more iterations will be needed before convergence.

• MATLAB/deconvlucy use "Biggs" acceleration. Matlab version R2020b was used in this case.

• For "real" data, when --periodic is not used, the input image is padded automagically during processing and the relevant part is cropped out at the end.

• Also works on Raspberry PI5 :) In that case it took 146 s.

Installation

These instructions should work under Linux, BSD, Windows (via WSL), and MacOS.

1. Get the dependencies. The required libraries should be found on most platforms, however, the installation process differs slightly. See INSTALL.md for per-platform advice.

2. Compile and install

mkdir builddir
cd builddir
cmake ..
cmake --build .
sudo make install

Once again, see INSTALL.md for more options.

Minimal usage example

To generate a parametric PSF and deconvolve an image, all you need is something like this:

# generate PSF.tif
dw_bw --resxy 130 \
--resz 250 \
--NA 1.46 \
--ni 1.518 \
--lambda 460 PSF.tiff
# Deconvolve image.tiff -> dw_image.tiff
dw --iter 50 image.tiff PSF.tiff

For available options, please see

dw --help
dw_bw --help

To validate that dw does not create random garbage, run it on /demo/dapi_001.tif

cd demo
make
imagej dapi_001.tif dw_dapi_001.tif

The run time on an AMD 3700x was 8s. To use GPU accelerated deconvolution, test

dw --iter 20 dapi_001.tif PSF_dapi.tif --gpu --prefix dwgpu

The results should be visually identical.

For more documentation see the short usage guide, and the manual pages for both binaries, man dw man dw_bw.

Bugs

Most likely there are bugs and they can only be fixed when they are known. Please open a new ticket if you have any issues with the program.

Alternatives

This is a non-complete list of alternative deconvolution software:

Deconvolution

Free and open source:

• Deconvolution Lab2

Commercial:

• Huygens
• Microvolution

Point spread functions

• PSF Generator

Others

• nd2tool Convert nd2 files (Nikon) to tif files. Can also generate scripts for deconvolution with dw.

References

[^1]: M. Bertero and P. Boccacci, A simple method for the reduction of boundary effects in the Richardson-Lucy approach to image deconvolution, A&A 437, 369-374 (2005). doi

[^2]: Richardson, William Hadley (1972). "Bayesian-Based Iterative Method of Image Restoration". JOSA. 62 (1): 55–59. doi

[^3]: Lucy, L. B. (1974). "An iterative technique for the rectification of observed distributions". Astronomical Journal. 79 (6): 745–754. doi

[^4]: Wang H, et al. Scaled Heavy-Ball Acceleration of the Richardson-Lucy Algorithm for 3D Microscopy Image Restoration. IEEE Trans Image Process. 2014 doi.

[^5]: Max Born. Principles of optics : electromagnetic theory of propagation, interference, and diffraction of light. Cambridge: Cambridge University Press, 2019. ISBN: 978-1-108-47743-7.

[^6]: F. Aguet. “Super-Resolution Fluorescence Microscopy Based on Physical Models”. EPFL Thesis no. 4418 (2009), 209 p. Swiss Federal Institute of Technology Lausanne (EPFL), May 2009 url

[^7]: Jizhou Li, Feng Xue, and Thierry Blu. “Fast and accurate three-dimensional point spread function computation for fluorescence microscopy”. In: Journal of the Optical Society of America A 34.6 (May 2017), p. 1029. doi

[^8]: D. Tolmachev, "VkFFT-A Performant, Cross-Platform and Open-Source GPU FFT Library," in IEEE Access, vol. 11, pp. 12039-12058, 2023, doi

[^9]: E. Wernersson et al. "Deconwolf enables high-performance deconvolution of widefield fluorescence microscopy images", in Nature Methods, 2024, doi