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About this Project

This project is being developed as a practical part of bachelor's thesis at Brno Universtiy of Technology - Faculty of Information Studies. It is as of now a work in progress, no results guaranteed.

The topic of this thesis is Generating a 3D Fingerprint Model. This application can be used to apply series of image processing filters to a fingerprint image to make it more suitable for conversion to 3D stl model and printing. It also includes the functionality to use generated image as a height map for generating an stl model. This model can either be planar or curved.

Prerequisites

For now this is only viable for ubuntu gnu/linux machines Before cloning repository, you need these to succesfully use the application.

  • python version 3.10 is a requirement might work on earlier python 3 versions

    sudo apt install python3.10
    
  • virtualenv for virtual enviroment creation

    pip install virtualenv
    

Installation

  1. Go to a suitable installation folder, for example Documents.

    cd /home/username/Documents
    
  2. Clone the repository to a suitable directory, for example

    git clone ssh://git@strade.fit.vutbr.cz:3022/xlanro00/BP_DP-xlanro00.git
    
  3. Go inside cloned directory

    cd BP_DP-xlanro00
    
  4. Create and enter the virtual enviroment.

    virtualenv .venv && source .venv/bin/activate
    
  5. Install required python modules from requirements.txt.

    pip install -r requirements.txt
    
  6. Run the application, as an example there is a file in res/examples called Palec_P4.tif. This is shown in the section below.

Filtering images

  • You will need to enter the virtual enviroment every time you want to use the application.
    source .venv/bin/activate
    

Once all the requirements are installed, the program is ready to use. There are two ways to enter the filters:

  1. manually list filter names and parameters from command line

    python3 src/main.py res/examples/Palec_P4.tif res/examples/Palec_P4_from_shell.png 600 total_variation weight=0.15 median ksize=5
    
  2. from preset saved in a json config file, that can be used to tune and modify existing presetrs, or create new ones

    python3 src/main.py res/examples/Palec_P4.tif res/examples/Palec_P4_from_preset.png 600 --config config/config.json git_example
    

Configuration and presets

There is an option to input the filter series as a preset from json configuration file.

General format Woking example

{
    "preset": [
        {
            "name": "filter_name",
            "parameter": value,
            "parameter": value
        },
        {
            "name": "filter_name",
            "parameter": value
        }
    ],
    "preset": [
        ...
    ]
    ...
}
        

{
    "git_example": [
        {
            "name": "denoise_tv_chambolle",
            "weight": 0.01,
            "iterations": 1
        },
        {
            "name": "median",
            "ksize": 3
        }
    ]
}
        

All the filters used and their parameters are described below.

Available filters with parameters

  • median blur

    • ksize - Kernel size (int)
  • gaussian blur

    • sigma - Gaussian kernel standart deviation (int)
  • bilateral blur

    • diameter - Diameter of pixel neighborhood used for filtering (int)
    • sigmaColor - Standard deviation for grayvalue/color distance (int)
    • sigmaSpace - Standard deviation for range distance in pixels (int)
  • bilateral_scikit

    • sigmaColor - Standard deviation for grayvalue/color distance (float)
    • sigmaSpace - Standard deviation for range distance in pixels (float)
  • nlmeans (non-local means)

    • patch_size - Size of patches used for denoising (int)
    • patch_distance - Distance in pixels where to search for patches (int)
    • h - Cut-off distance, higher means more smoothed image (float)
  • total_variation

    • weight - Denoising weight. (float)
  • block_match

    • sigma - ? (?)
  • unsharp mask scikit

    • radius - Radius of the gaussian filter (int)
    • amount - Strength of the unsharp mask (float)
  • farid

  • meijering

  • sato

  • hessian

    • sigmas - ? (float)
  • invert

  • scale_values

  • binarize

    • threshold - value to cut differentiate pixels (int)
    • maxval - maximal value (int) ??
    • type - ? (str)
  • binarize_otsu

  • add_margin

    • margin - number of pixels to add to the sides of the image (int)
    • color - color value of newly added pixels (int)
  • erode

    • kernel - kernel shape (numpy.matrix)
  • dilate

    • kernel - kernel shape (numpy.matrix)

Comparison

Image before processing the fingerprint and after applying a presets.

Before After

Generating curved finger model

It is possible to generate 3D printable stl model using --stl switch, which requires aditional parameter containing stl filename. In base mode the output model will be a curved finger model, with optional parameters following the filename controlling its shape. First optional parameter is papilar line height, second rate of curvature along x axis and the third is the rate of curvature along y axis.

  • General form for curved stl generation

    python3 src/main.py input_file output_file dpi --config config_file preset --stl c height_line height_base curvature_x curvature_y
    
  • Working example curved stl generation

    python3 src/main.py res/examples/Palec_P4.tif res/examples/Palec_P4_from_preset.png 600 --config config/config.json git_example --stl c 2 10 2 2
    

Generating planar finger model

Using -p switch makes the generated model planar. Optional parameters are model base thickness and papilar lines height, they are set after stl file name.

  • General form for planar stl generation

    python3 src/main.py input_file output_file dpi --config config_file preset --stl p height_line height_base
    
  • Working example planar stl generation

    python3 src/main.py res/examples/Palec_P4.tif res/examples/Palec_P4_from_preset.png 600 --config config/config.json git_example --stl p 2 10
    

Mapping to existing finger model

This section will be added later, (if implemented) mapping of fingerprint to a given finger model.

  • General form for planar stl generation
    python3 src/main.py input_file output_file dpi --config config_file preset --stl m height_line height_base finger_file
    

Usage

usage: main.py [-h] [-m | --mirror | --no-mirror] input_file output_file dpi ([-c | --config config_file preset] | [filters ...]) [-s | --stl_file p height_line height_base | --stl_file c height_line height_base curv_rate_x curv_rate_y | --stl_file m height_line height_base finger_file]

Program for processing a 2D image into 3D fingerprint.

positional arguments: input_file input file path output_file output file path dpi dpi of used scanner filters list of filter names and their parameters in form [filter_name1 param1=value param2=value filter_name2 param1=value...]

options: -h, --help show this help message and exit -m, --mirror, --no-mirror switch to mirror input image -s [STL_FILE ...], --stl_file [STL_FILE ...] create stl model from processed image -c CONFIG CONFIG, --config CONFIG CONFIG pair: name of the config file with presets, name of the preset

Roadmap

  • Load and store image
  • Apply basic image processing filters
    • Scale the image using given dpi
  • Create filter library with more filters
    • Add more suitable filters to the library
  • Use presets from config files
    • Add the option to save current filter preset to config file
  • Add the option to modify filter parameters
  • Convert the processed image to stl lithophane
  • Add the option to curve the lithophane into the shape of a finger
  • Add the option to map the fingerprint onto a given finger model
  • Export final model ready for 3D print

Author

Rostislav Lán - xlanro00@stud.fit.vutbr.cz

Supervisor

Ing. Petr Malaník

Project Link: https://strade.fit.vutbr.cz/git/xlanro00/BP_DP-xlanro00