utils_edit_image.py

# Copyright 2023 Google LLC
#
# 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
#
#     https://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 module for image generation and editing with Imagen
"""


import io
import numpy as np
from PIL import Image
import streamlit as st
from streamlit_drawable_canvas import st_canvas


def edit_image_canvas(result_image_key: str, background_image: bytes):
    """This function allows users to edit an image using a Streamlit canvas component. 
    The user can select a painting tool and stroke width, and then draw on the canvas. 
    The edited image is then stored in the Streamlit session state and can be displayed.

    Args:
        result_image_key (str): 
            The key to store the edited image in the Streamlit session state.
        background_image (bytes): 
            The background image to be edited.
    """
    # Specify canvas parameters in application
    drawing_dict = {
        "⬜ Rectangle": "rect",
        "🖌️ Brush": "freedraw",
        "⚪ Circle": "circle",
        "📏 Move/Scale/Rotate": "transform"
    }
    
    drawing_mode = st.selectbox(
        "[Optional] Draw a mask where you want to edit the image using one of the provided drawing tools", drawing_dict.keys(),
        key=f"{result_image_key}_canvas_selectbox"
    )
    
    stroke_width = st.slider(
        "Stroke width: ", 10, 50, 20, key=f"{result_image_key}_canvas_slider")
    
    background_image = Image.open(io.BytesIO(background_image))
    height = int(background_image.size[1] / (background_image.size[0] / 704))
    background = Image.new('RGB', background_image.size)

    # Create a canvas component
    canvas_result = st_canvas(
        fill_color="rgba(255, 255, 255, 1)",  # Fixed fill color with some opacity
        stroke_width=stroke_width,
        stroke_color="rgba(255, 255, 255, 1)",
        background_color="#000",
        background_image=background_image,
        update_streamlit=True,
        height=height,
        width=704,
        drawing_mode=drawing_dict[drawing_mode],
        point_display_radius=0,
        key=f"{result_image_key}_canvas",
    )

    # Do something interesting with the image data and paths
    if canvas_result.image_data is not None and canvas_result.image_data.any():
        foreground = Image.fromarray(canvas_result.image_data)
        foreground_merge = foreground.resize(background.size)
        image_merge = background.copy()
        image_merge.paste(foreground_merge, (0, 0), foreground_merge)
        with io.BytesIO() as buffer_out:
            image_merge.save(buffer_out, format="PNG")
            bytes_data = buffer_out.getvalue()
        st.session_state[result_image_key] = bytes_data
        # st.image(image_merge.resize(foreground.size))