gobo.ies

Contents

• Introduction
• Installation
• Usage
• Contributing
• License

Introduction

The gobo.ies project is a Python-based tool that generates IES (Illuminating Engineering Society) files from image inputs. IES files are a standard format used to represent the photometric distribution of a light source, essentially describing how the light is emitted. This tool allows users to create these files from images.

It leverages the polarTransform library to convert the image into a polar coordinate system, which is essential for representing the light distribution around a source. The script then calculates the luminous intensity based on the pixel values in the transformed image and generates the IES file.

Installation

To install the required dependencies, use pip:

pip install -r requirements.txt

This will install the following packages:

• polarTransform
• Pillow
• numpy

Usage

1. Ensure you have the required libraries installed (see Installation).
2. Run the image2ies.py script, providing the path to your image file, the desired beam angle, and the maximum candela value. You can also optionally specify the output filename, and the angle steps for theta and phi.

   python src/image2ies.py [-h] [-o <output.ies>] [-s <source.ies>] [-b BEAM_ANGLE] [-c MAX_CANDELA] [-t THETA_STEP]
                    [-p PHI_STEP] [-e [EDGE_FADE ...]] [-a] <image.jpg>

   • -h, --help: Show the help message and exit
   • -o, --output <output.ies> (optional): The name of the output IES file. Defaults to image file name with .ies extension
   • -s <source.ies>, --source <source.ies> (optional): Filename of an .ies file to use as the source distribution.
   • -a, --allow_spill (optional): If using <source.ies>, allow spill light from beyond beam angle.
   • -b, --beam_angle BEAM_ANGLE_DEG (optional): The beam angle of the light source in degrees.
   • -e [EDGE_FADE ...], --edge_fade [shape parameters ...] (optional): Fade edge optionally followed by up to 3 values to specify shape:
     • [WIDTH_INSIDE_BEAM] (degrees) width of fade inside beam angle,
     • [WIDTH_OUTSIDE_BEAM] (degrees) width of fade beyond beam angle, and
     • [SLOPE] (ratio), a slope of 0 is linear, 0.5 is a smooth s-curve, 1 is a sharp edge (same as no edge fade).
   • -c, --max_candela MAX_CANDELA (optional): The maximum luminous intensity (candela) of the light source.
   • -t, --theta_step THETA_STEP (optional): Step size for vertical angles (theta) in degrees. Defaults to 1.0 degree.
   • -p, --phi_step PHI_STEP (optional): Step size for horizontal angles (phi) in degrees. Defaults to 2.5 degrees.
   • <image.jpg>: Path to the input image file (e.g., JPEG, PNG).

For example:

python src/image2ies.py -b 60 -c 1000 -t 5 -p 10 -o my_light.ies example_image.jpg

This will generate an IES file named my_light.ies based on the image example_image.jpg, with a beam angle of 60 degrees and a maximum candela of 1000.

Contributing

We welcome contributions to this project! If you'd like to contribute, please follow these steps:

1. Fork the repository.
2. Create a new branch for your feature or bug fix.
3. Make your changes.
4. Ensure your code follows the project's style guidelines (Black).
5. Submit a pull request

License

This project is released under the Creative Commons Zero v1.0 Universal license. See the LICENSE file for more information.