This project is a desktop application designed to assist users in creating custom digital filters through zeros-poles placement on the z-plane. Implemented using Python and PyQt5, the application provides an interactive interface for filter design and real-time signal processing.
The core of the application is the interactive z-plane plot, which includes:
- Placing Zeros and Poles: Users can click on the plot to place zeros and poles. These elements are essential for defining the characteristics of the digital filter.
- Modifying Zeros and Poles: Dragging allows users to adjust the positions of zeros and poles, providing a dynamic way to tweak filter parameters.
- Deleting Elements: Users can click on a zero or pole to delete it, enabling easy correction of mistakes or adjustments.
- Conjugate Addition: For complex elements, users have the option to add conjugates automatically, simplifying the design of symmetric filters.
As users interact with the z-plane plot, the application provides real-time updates of the filter's frequency response:
- Magnitude Response: Displays how the amplitude of the filter varies with frequency.
- Phase Response: Shows how the phase of the filter varies with frequency. These visualizations help users understand the impact of their design choices on the filter's performance.
The application supports applying the designed filter to a real-time signal:
- Filtering a Lengthy Signal: Users can load a signal with at least 10,000 points and observe how the filter processes it over time.
- Adjustable Processing Speed: A slider allows users to control the speed of the filtering process, from processing 1 point per second to 100 points per second, or any rate in between.
- Signal Visualization: The application plots both the original and filtered signals, showing the filtering progress in real-time.
Users can create real-time signals by moving the mouse on a designated area:
- Mouse Movement Input: The x- or y-coordinate of the mouse generates the input signal.
- Frequency Control: Faster mouse movements create higher frequency signals, while slower movements create lower frequency signals.
To correct phase distortions introduced by the filter, the application includes a library of all-pass filters:
- All-Pass Filter Library: Users can browse and visualize the zero-pole combinations and phase responses of predefined all-pass filters.
- Custom All-Pass Filters: If the library filters are insufficient, users can create custom all-pass filters by specifying parameters.
- Enable/Disable All-Pass Filters: Users can selectively enable or disable added all-pass filters through a drop-down menu or checkboxes, allowing for fine-tuning of the filter design.
To run this application, follow these steps:
-
Clone the repository:
git clone https://github.com/omarrrefaatt/realtime-digital-filter-design.git cd realtime-digital-filter-design -
Run the application:
python main.py
- Placing: Click on the z-plane plot to add a zero or pole.
- Modifying: Drag the placed zeros or poles to new positions as needed.
- Deleting: Right-click on a zero or pole to remove it.
- Adding Conjugates: Use the provided option to add conjugate pairs for complex zeros and poles.
- The application displays the magnitude and phase responses of the filter in real-time as you modify the z-plane plot.
- Use these visualizations to adjust the filter design for the desired frequency characteristics.
- Loading a Signal: Load a signal file to apply the filter.
- Adjusting Speed: Use the slider to control the processing speed of the filter.
- Viewing Results: The application plots the original and filtered signals, showing the effects of the filter in real-time.
- Mouse Input: Move the mouse in the designated area to generate real-time input signals.
- Frequency Control: Adjust the speed of mouse movement to control the signal frequency.
- Browsing the Library: Explore the provided all-pass filters and visualize their characteristics.
- Creating Custom Filters: Define custom all-pass filters if the library filters are insufficient.
- Enabling/Disabling Filters: Use the interface to enable or disable selected all-pass filters to achieve the desired phase correction.
- Fork the repository.
- Create a new branch (
git checkout -b feature-branch). - Commit your changes (
git commit -am 'Add new feature'). - Push to the branch (
git push origin feature-branch). - Create a new Pull Request.
- EarLevel Engineering for inspiration and resources on digital filter design.