Create_Intensity_Lookup.py

# coding=utf-8
"""
//////////////////////////////////////////////////////////////////////////////////
// OpenNX4 - Open source firmware for Barco NX4 tiles
// Company: Bohemian Bits
// Engineer: Richard Aplin (Twitter: @DrTune)
// Copyright (C) 2017 Richard Aplin
// Released under the Attribution-NonCommercial 2.0 Generic (CC BY-NC 2.0)
// You may not use this code or a derived work for commercial purposes unless you have a commercial license, contact drtune@gmail.com
//////////////////////////////////////////////////////////////////////////////////
"""
from __future__ import division, print_function
from NX4CommsHeaderReader import NX4

# output Xilinx ISE  "COE" file (coeffs) to be includes in the ram 8b->12b pixel lookup
with open("ipcore_dir/Intensity_Lookup.coe", "w") as fout:

    # http://jared.geek.nz/2013/feb/linear-led-pwm

    bits = NX4.INTERNAL_PIXEL_WIDTH_BITS

    res = """
    ;GENERATED BY CREATE_INTENSITY_LOOKUP.PY DO NOT EDIT
    ; Generated for a 256x{:d} dual port BRAM
    memory_initialization_radix=16;
    memory_initialization_vector=
    """.format(bits)

    fullScale = 1 << bits


    def cie1931(L):
        L = L * 100.0
        if L <= 8:
            return L / 902.3
        else:
            return ((L + 16.0) / 116.0) ** 3


    if True:
        out = []

        for n in range(256):
            # adjust for eye response
            if False:
                gamma = pow(fullScale - 1, (n / 256.0))
                gamma = int(gamma * fullScale) >> bits
            else:
                gamma = round(cie1931(float(n) / 255) * (fullScale - 1))

            if n == 0:
                gamma = 0
            out.append(gamma)
        res += (",".join(["{:03x}".format(n) for n in out]))

    res += ";\n"

    print(res, file=fout)
    print(res)