numpyHDR/readme.md

numpyHDR

• Micro Library for HDR image creation using the Mertens Fusion Alghoritm
• Optional Raspicam integration with picamera2 lib
• CLI Application "makehdr.py"
• Processing time on raspi zero ca 15 min with full res 12MP files.

Intention

• numpy and PIL, picamera2 for Raspicam funtionality.
• Whenever dependencies of other bigger image librarys aren´t satisfyable.
• 32-bit armv6 or oudated Kernels etc.

Function

Use makehdr.py CLI app for testing before implementation

• Captures an exposure bracket stack from the raspicam as fast as possible
• Alternatively from image sequences form file
• Either direct processing or save files in between
• Uses a conversion of the Mertens Fusion alghoritm
• Stretches Information to the full spectrum like Contrast or compression
• Lifts the shadows softly with an envelope.
• Clips to Image range and saves via PIL

Setup

• Download and install dependencies from requirements.txt into env
• pip install -r requirements.txt
• Install picamera2 and libcamera
• pip install picamera2
• pip install libcamera

Usage

• Start makehdr.py

• python3 makehdr.py

• Follow commandline instructions

• Be patient on Raspi zero

• Example on how to use the library can be found in makehdr.py

Using the library

Import numpyHDR modules

• import file_utility as file
• import numpyHDR as hdr
• import picamburst as pcb

Get image arrays from raspicam

• stack = pcb.get_exposure_stack()

Get image arrays from files

• stack = file.openImageList(path_list, True)

Process HDR with mertens fusion and post effects

• result = hdr.process(stack, 1, 1, 1, True)

Save Result to File

• The filename gets extended by ".jpg" and "_hdr" automatically
• file = file.saveResultToFile(result, 'hdr/result', 75)