edit_image.py

import collections
import math
import os
import random
import subprocess
from pathlib import Path
from struct import pack
from typing import Dict, Tuple

import cv2
from jinja2 import Template
from PIL import Image


def edit_image(img_path: str, change: str, value: float) -> Image.Image:
    if math.isclose(parameter_range[change]["default"], value):
        print(f"default called: {change}: {value}")
        return Image.open(img_path)

    if "lcontrast" == change:  # not my fault: localcontrast xmp in darktable is broken atm. no idea why
        img = cv2.imread(img_path)
        img_lab = cv2.cvtColor(img, cv2.COLOR_BGR2LAB)
        l, a, b = cv2.split(img_lab)

        cl = cv2.createCLAHE(clipLimit=value, tileGridSize=(8, 8)).apply(l)

        limg = cv2.merge((cl, a, b))

        img = cv2.cvtColor(limg, cv2.COLOR_LAB2RGB)
        img = Image.fromarray(img)
        return img

    edit_file = "/tmp/edit.xmp"
    out_file = f"/tmp/out{Path(img_path).suffix}"

    create_xmp_file(edit_file, change, value)

    subprocess.run(["darktable-cli", img_path, edit_file, out_file, "--core", "--library", ":memory:"])
    img = Image.open(out_file)
    os.remove(out_file)
    return img


def create_xmp_file(path: str, change: str, value: float):
    if "contrast" == change or "brightness" == change or "saturation" == change:
        template_file = "./darktable_xmp/colisa.xmp"
        param_index = ["contrast", "brightness", "saturation"].index(change)
        default_str = "".join(["%02x" % b for b in bytearray(pack("f", 0))])
        change_val_enc = "".join(["%02x" % b for b in bytearray(pack("f", value))])
        change_str = "".join([change_val_enc if _ == param_index else default_str for _ in range(3)])

    if "shadows" == change or "highlights" == change:
        template_file = "./darktable_xmp/shadhi.xmp"
        if "shadows" == change:
            change_str = f"000000000000c842{''.join(['%02x' % b for b in bytearray(pack('f', value))])}000000000000c84200000000000048420000c842000048427f000000bd37863500000000"
        elif "highlights" == change:
            change_str = f"000000000000c8420000484200000000{''.join(['%02x' % b for b in bytearray(pack('f', float(value)))])}00000000000048420000c842000048427f000000bd37863500000000"

    if "exposure" == change:
        template_file = "./darktable_xmp/exposure.xmp"
        change_str = f"0000000000000000{''.join(['%02x' % b for b in bytearray(pack('f', value))])}00004842000080c0"

    if "vibrance" == change:
        template_file = "./darktable_xmp/vibrance.xmp"
        change_str = "".join(["%02x" % b for b in bytearray(pack("f", value))])

    if "temperature" == change or "tint" == change:
        template_file = "./darktable_xmp/temperature.xmp"
        change_str = parameter_range[change]["rangemapping"][value]

    with open(template_file) as template_file:
        Template(template_file.read()).stream(value=change_str).dump(path)


parameter_range = collections.defaultdict(dict)
parameter_range["contrast"]["min"] = -1
parameter_range["contrast"]["default"] = 0
parameter_range["contrast"]["max"] = 1
parameter_range["contrast"]["range"] = [-1.0, -0.8, -0.6, -0.4, -0.2, 0.0, 0.2, 0.4, 0.6, 0.8, 1.0]

parameter_range["brightness"] = parameter_range["contrast"]
parameter_range["saturation"] = parameter_range["contrast"]

parameter_range["shadows"]["min"] = -100
parameter_range["shadows"]["default"] = 50
parameter_range["shadows"]["max"] = 100
parameter_range["shadows"]["range"] = [-100, -80, -60, -40, -20, 0, 20, 40, 50, 60, 80, 100]

parameter_range["highlights"]["min"] = -100
parameter_range["highlights"]["default"] = -50
parameter_range["highlights"]["max"] = 100
parameter_range["highlights"]["range"] = [-100, -80, -60, -50, -40, -20, 0, 20, 40, 60, 80, 100]

parameter_range["exposure"]["min"] = -3
parameter_range["exposure"]["default"] = 0
parameter_range["exposure"]["max"] = 3
parameter_range["exposure"]["range"] = [-3.0, -2.4, -1.8, -1.2, -0.6, 0.0, 0.6, 1.2, 1.8, 2.4, 3.0]

parameter_range["vibrance"]["min"] = 0
parameter_range["vibrance"]["default"] = 25
parameter_range["vibrance"]["max"] = 100
parameter_range["vibrance"]["range"] = [0, 20, 25, 40, 60, 80, 100]

parameter_range["temperature"]["min"] = 1000
parameter_range["temperature"]["default"] = 6500
parameter_range["temperature"]["max"] = 25000
parameter_range["temperature"]["range"] = [
    2000,
    3000,
    5000,
    6000,
    6500,
    7000,
    8000,
    10000,
    12000,
    14000,
    16000,
    18000,
    20000,
    22000,
    25000,
]
parameter_range["temperature"][
    "rangemapping"
] = {  # encoded RGB values, since darktable can't save temperature directly
    2000: "6c71833e0000803f495cfd410000807f",
    3000: "a623f43e0000803f9b9446400000807f",
    4000: "e3832c3f0000803f705af13f0000807f",
    5000: "f954543f0000803f9317ad3f0000807f",
    6000: "ef39733f0000803f8c138b3f0000807f",
    6500: "7405803f0000803fc301803f0000807f",
    7000: "f39e853f0000803f72e86e3f0000807f",
    8000: "17208f3f0000803ffed8553f0000807f",
    9000: "c8c2963f0000803fdeb9443f0000807f",
    10000: "d3029d3f0000803fd95f383f0000807f",
    11000: "5035a23f0000803fcc172f3f0000807f",
    12000: "9e96a63f0000803fb3e4273f0000807f",
    13000: "ae52aa3f0000803f182a223f0000807f",
    14000: "328aad3f0000803f68821d3f0000807f",
    15000: "f555b03f0000803f08a9193f0000807f",
    16000: "13c9b23f0000803f176e163f0000807f",
    17000: "7ff2b43f0000803f37af133f0000807f",
    18000: "10deb63f0000803f2753113f0000807f",
    19000: "4295b83f0000803ff7460f3f0000807f",
    20000: "c61fba3f0000803f2e7c0d3f0000807f",
    21000: "e483bb3f0000803f93e70b3f0000807f",
    22000: "cbc6bc3f0000803f50800a3f0000807f",
    23000: "caecbd3f0000803f593f093f0000807f",
    24000: "7ff9be3f0000803f021f083f0000807f",
    25000: "f3efbf3f0000803fa91a073f0000807f",
}

parameter_range["tint"]["min"] = 0.2
parameter_range["tint"]["default"] = 1.0
parameter_range["tint"]["max"] = 2.3
parameter_range["tint"]["range"] = [0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25]
parameter_range["tint"]["rangemapping"] = {  # encoded RGB values, since darktable can't save tint directly
    0.2: "f16ad3bf0000803f79fd38420000807f",
    0.3: "020b05c00000803f063824410000807f",
    0.4: "0bee3ac00000803fb6e0af400000807f",
    0.5: "cd4cabc00000803f804067400000807f",
    0.6: "bce1b4c20000803fc2b926400000807f",
    0.7: "c63ea9400000803f370cfd3f0000807f",
    0.75: "be6255400000803fb43bdf3f0000807f",
    0.8: "d5ba18400000803fa425c63f0000807f",
    0.85: "b3d7e93f0000803f3fbfb03f0000807f",
    0.9: "5d93ba3f0000803fc4469e3f0000807f",
    0.95: "630b993f0000803f132c8e3f0000807f",
    1.0: "7405803f0000803fc301803f0000807f",
    1.05: "dc43593f0000803f91e6663f0000807f",
    1.1: "da553a3f0000803f797c503f0000807f",
    1.15: "1217213f0000803f965b3c3f0000807f",
    1.2: "13180c3f0000803fb52e2a3f0000807f",
    1.25: "25b7f43e0000803f70b0193f0000807f",
    1.3: "6c5ad63e0000803fa5a70a3f0000807f",
    1.4: "5519a53e0000803fb980e03e0000807f",
    1.5: "6cb97d3e0000803f31a2b33e0000807f",
    1.6: "cea2403e0000803f8f098d3e0000807f",
    1.7: "dfb60e3e0000803f1af8563e0000807f",
    1.8: "df4eca3d0000803f41181c3e0000807f",
    1.9: "8a08843d0000803f810cd03d0000807f",
    2.0: "35ae0f3d0000803f9792663d0000807f",
    2.1: "f6a21d3c0000803f1089803c0000807f",
    2.2: "1f1f4fbc0000803f8250abbc000080ff",
    2.3: "4c3404bd0000803f0c825dbd000080ff",
}

parameter_range["lcontrast"]["min"] = 0
parameter_range["lcontrast"]["default"] = 0
parameter_range["lcontrast"]["max"] = 40
parameter_range["lcontrast"]["range"] = [0, 0.2, 0.4, 0.6, 0.8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40]


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser()
    parser.add_argument("--image", type=str, help="path to a single image", default="/data/442284.jpg")
    parser.add_argument("--parameter", type=str, help="what to change: brightness, contrast...")
    parser.add_argument("--value", type=float, help="change value")
    parser.add_argument("--out", type=str, help="dest for edited images", default="/data/output.jpg")
    args = parser.parse_args()
    edit_image(img_path=args.image, change=args.parameter, value=args.value).save(args.out)

# darktable xmp crashkurs
# to encode
# "".join([ "%02x" % b for b in bytearray(pack("f", 10.0))])
# to decode
# unpack("f", b"\x00\x00\x96\x42")
# unpack("f", bytes.fromhex("00009642"))