QDSpy_gamma.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
QDSpy module - gamma correction functions

Copyright (c) 2013-2024 Thomas Euler
All rights reserved.

2021-10-15 - Adapt to LINUX
"""
# ---------------------------------------------------------------------
__author__ = "code@eulerlab.de"

import numpy
import time
import platform
import QDSpy_global as glo
import QDSpy_stim as stm
import Libraries.log_helper as _log

PLATFORM_WINDOWS = platform.system == "Windows"
if PLATFORM_WINDOWS:
    from ctypes import windll
    from ctypes.wintypes import LPCVOID

# ---------------------------------------------------------------------
def generateLinearLUT():
    '''Return a linear LUT (see setGammaLUT for details)
    '''
    tempLUT = []
    for j in range(3):
        temp = list(range(256))
        temp = [float(v) / 255.0 for v in temp]
        tempLUT.append(temp)

    newLUT = numpy.array(tempLUT)
    newLUT = (255 * newLUT).astype(numpy.uint16)
    newLUT.byteswap(True)
    return newLUT


# ---------------------------------------------------------------------
def generateInverseLUT():
    '''.. for testing purposes
    '''
    tempLUT = []
    for j in range(3):
        temp = list(range(255, -1, -1))
        temp = [float(v) / 255.0 for v in temp]
        tempLUT.append(temp)

    newLUT = numpy.array(tempLUT)
    newLUT = (255 * newLUT).astype(numpy.uint16)
    newLUT.byteswap(True)
    return newLUT


# ---------------------------------------------------------------------
def setGammaLUT(_winDC, _LUT):
    '''Set a look-up table (LUT) that allows to correct all presented color
    values, e.g. if the presentation device is not linear.
    `_LUT` has to be an uint16-type 3x256 numpy array.
    '''
    if not PLATFORM_WINDOWS:
        return stm.StimErrC.notYetImplemented

    if (len(_LUT) != 3) or (len(_LUT[0]) != 256):
        return stm.StimErrC.invalidDimensions

    # For some unclear reason it fails to return a valid result when called
    # for the first time ...
    for j in range(5):
        try:
            res = windll.gdi32.SetDeviceGammaRamp(
                _winDC & LPCVOID(0xFFFFFFFF), _LUT.ctypes
            )
        except TypeError:
            res = windll.gdi32.SetDeviceGammaRamp(_winDC, _LUT.ctypes)
        time.sleep(0.1)
        if res:
            break

    if res:
        _log.Log.write("OK", "SetDeviceGammaRamp worked")
        return stm.StimErrC.ok
    else:
        _log.Log.write("ERROR", "SetDeviceGammaRamp failed")
        return stm.StimErrC.SetGammaLUTFailed


# ---------------------------------------------------------------------
def restoreGammaLUT(_winDC):
    return setGammaLUT(_winDC, generateLinearLUT())


# ---------------------------------------------------------------------
def loadGammaLUT(_fName):
    _log.Log.write(" ", "Loading user-defined gamma LUT file ...")

    try:
        rgb = []
        r = []
        g = []
        b = []
        fName = _fName + glo.QDSpy_LUTFileExt
        with open(fName, "r") as LUTFile:
            for line in LUTFile:
                rgb = [int(v.strip()) for v in line.split(",")]
                r.append(rgb[0])
                g.append(rgb[1])
                b.append(rgb[2])

        newLUT = numpy.array([r, g, b])
        newLUT = newLUT.astype(numpy.uint16)
        _log.Log.write("ok", "... done")
        return newLUT

    except IOError:
        _log.Log.write("ERROR", "gamma LUT file `{0}` not found".format(fName))
        return generateLinearLUT()


# ---------------------------------------------------------------------