scripts/py/gen_rgb_cpp.py

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#  SPDX-License-Identifier: Apache-2.0
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

"""
Utility script to convert a set of RGB images in a given location into
corresponding cpp files and a single hpp file referencing the vectors
from the cpp files.
"""
import glob
import math
import typing
from argparse import ArgumentParser
from dataclasses import dataclass
from pathlib import Path

import numpy as np
from PIL import Image, UnidentifiedImageError
from jinja2 import Environment, FileSystemLoader

from gen_utils import GenUtils

# pylint: disable=duplicate-code
parser = ArgumentParser()

parser.add_argument(
    "--image_path",
    type=str,
    help="path to images folder or image file to convert."
)

parser.add_argument(
    "--source_folder_path",
    type=str,
    help="path to source folder to be generated."
)

parser.add_argument(
    "--header_folder_path",
    type=str,
    help="path to header folder to be generated."
)

parser.add_argument(
    "--image_size",
    type=int,
    nargs=2,
    help="Size (width and height) of the converted images."
)

parser.add_argument(
    "--license_template",
    type=str,
    help="Header template file",
    default="header_template.txt"
)

parsed_args = parser.parse_args()

env = Environment(loader=FileSystemLoader(Path(__file__).parent / 'templates'),
                  trim_blocks=True,
                  lstrip_blocks=True)


# pylint: enable=duplicate-code
@dataclass
class ImagesParams:
    """
    Template params for Images.hpp and Images.cc
    """
    num_images: int
    image_size: typing.Sequence
    image_array_names: typing.List[str]
    image_filenames: typing.List[str]


def write_hpp_file(
        images_params: ImagesParams,
        header_file_path: Path,
        cc_file_path: Path,
        header_template_file: str,
):
    """
    Write Images.hpp and Images.cc

    @param images_params:           Template params
    @param header_file_path:        Images.hpp path
    @param cc_file_path:            Images.cc path
    @param header_template_file:    Header template file name
    """
    print(f"++ Generating {header_file_path}")
    hdr = GenUtils.gen_header(env, header_template_file)

    image_size = str(images_params.image_size[0] * images_params.image_size[1] * 3)

    env \
        .get_template('Images.hpp.template') \
        .stream(common_template_header=hdr,
                imgs_count=images_params.num_images,
                img_size=image_size,
                var_names=images_params.image_array_names) \
        .dump(str(header_file_path))

    env \
        .get_template('Images.cc.template') \
        .stream(common_template_header=hdr,
                var_names=images_params.image_array_names,
                img_names=images_params.image_filenames) \
        .dump(str(cc_file_path))


def resize_crop_image(
        original_image: Image.Image,
        image_size: typing.Sequence
) -> np.ndarray:
    """
    Resize and crop input image

    @param original_image:  Image to resize and crop
    @param image_size:      New image size
    @return:                Resized and cropped image
    """
    # IFM size
    ifm_width = image_size[0]
    ifm_height = image_size[1]

    # Aspect ratio resize
    scale_ratio = (float(max(ifm_width, ifm_height))
                   / float(min(original_image.size[0], original_image.size[1])))
    resized_width = int(original_image.size[0] * scale_ratio)
    resized_height = int(original_image.size[1] * scale_ratio)
    resized_image = original_image.resize(
        size=(resized_width, resized_height),
        resample=Image.Resampling.BILINEAR
    )

    # Crop the center of the image
    resized_image = resized_image.crop((
        (resized_width - ifm_width) / 2,  # left
        (resized_height - ifm_height) / 2,  # top
        (resized_width + ifm_width) / 2,  # right
        (resized_height + ifm_height) / 2  # bottom
    ))

    return np.array(resized_image, dtype=np.uint8).flatten()


def write_individual_img_cc_file(
        rgb_data: np.ndarray,
        image_filename: str,
        cc_filename: Path,
        header_template_file: str,
        array_name: str
):
    """
    Write image.cc

    @param rgb_data:                Image data
    @param image_filename:          Image file name
    @param cc_filename:             image.cc path
    @param header_template_file:    Header template file name
    @param array_name:              C++ array name
    """
    print(f"++ Converting {image_filename} to {cc_filename.name}")

    hdr = GenUtils.gen_header(env, header_template_file, image_filename)

    hex_line_generator = (', '.join(map(hex, sub_arr))
                          for sub_arr in np.array_split(rgb_data, math.ceil(len(rgb_data) / 20)))
    env \
        .get_template('image.cc.template') \
        .stream(common_template_header=hdr,
                var_name=array_name,
                img_data=hex_line_generator) \
        .dump(str(cc_filename))


def main(args):
    """
    Convert images
    @param args:    Parsed args
    """
    # Keep the count of the images converted
    image_idx = 0
    image_filenames = []
    image_array_names = []

    if Path(args.image_path).is_dir():
        filepaths = sorted(glob.glob(str(Path(args.image_path) / '**/*.*'), recursive=True))
    elif Path(args.image_path).is_file():
        filepaths = [args.image_path]
    else:
        raise OSError("Directory or file does not exist.")

    for filepath in filepaths:
        filename = Path(filepath).name

        try:
            original_image = Image.open(filepath).convert("RGB")
        except UnidentifiedImageError:
            print(f"-- Skipping file {filepath} due to unsupported image format.")
            continue

        image_filenames.append(filename)

        # Save the cc file
        cc_filename = (Path(args.source_folder_path) /
                       (Path(filename).stem.replace(" ", "_") + ".cc"))
        array_name = "im" + str(image_idx)
        image_array_names.append(array_name)

        rgb_data = resize_crop_image(original_image, args.image_size)
        write_individual_img_cc_file(
            rgb_data, filename, cc_filename, args.license_template, array_name
        )

        # Increment image index
        image_idx = image_idx + 1

    header_filepath = Path(args.header_folder_path) / "InputFiles.hpp"
    common_cc_filepath = Path(args.source_folder_path) / "InputFiles.cc"

    images_params = ImagesParams(image_idx, args.image_size, image_array_names, image_filenames)

    if len(image_filenames) > 0:
        write_hpp_file(images_params, header_filepath, common_cc_filepath, args.license_template)
    else:
        raise FileNotFoundError("No valid images found.")


if __name__ == '__main__':
    main(parsed_args)