app.py

import gradio as gr
import csv
from io import StringIO
from PIL import Image
import numpy as np
import base64

# Define the annotation types
ANNOTATION_TYPES = ['rect', 'circle']

# Define the Annotation class
class Annotation:
    def __init__(self, x, y, width, height, annotation_type):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.type = annotation_type

# Define the Gradio interface
def annotate_images(images):
    # Define the canvas size
    canvas_size = (600, 600)

    # Define the initial state
    state = {
        'image': None,
        'annotations': [],
        'annotation_type': ANNOTATION_TYPES[0],
        'start_point': None
    }

    # Define the canvas drawing function
    def draw_canvas(canvas, image_data, annotations):
        # Convert the image data to a PIL Image object
        image = Image.fromarray(image_data)

        # Resize the image to fit the canvas
        image = image.resize(canvas_size)

        # Draw the image on the canvas
        canvas.draw_image(image, (canvas_size[0]/2, canvas_size[1]/2))

        # Draw the annotations on the canvas
        for annotation in annotations:
            x, y, width, height = annotation.x, annotation.y, annotation.width, annotation.height
            if annotation.type == 'rect':
                canvas.draw_rect(x, y, width, height, stroke_color='red')
            elif annotation.type == 'circle':
                radius = np.sqrt(np.power(width, 2) + np.power(height, 2)) / 2
                center_x, center_y = x + width / 2, y + height / 2
                canvas.draw_circle(center_x, center_y, radius, stroke_color='red')

    # Define the canvas mousedown event handler
    def canvas_mousedown(canvas, x, y):
        state['start_point'] = (x, y)

    # Define the canvas mousemove event handler
    def canvas_mousemove(canvas, x, y):
        if state['start_point'] is not None:
            start_x, start_y = state['start_point']
            end_x, end_y = x, y
            annotation_type = state['annotation_type']
            draw_annotation(canvas, start_x, start_y, end_x, end_y, annotation_type)

    # Define the canvas mouseup event handler
    def canvas_mouseup(canvas, x, y):
        if state['start_point'] is not None:
            start_x, start_y = state['start_point']
            end_x, end_y = x, y
            annotation_type = state['annotation_type']
            add_annotation(start_x, start_y, end_x, end_y, annotation_type)
            state['start_point'] = None

    # Define the add annotation function
    def add_annotation(start_x, start_y, end_x, end_y, annotation_type):
        # Calculate the width and height of the annotation
        width = np.abs(start_x - end_x)
        height = np.abs(start_y - end_y)

        # Create the annotation object
        annotation = Annotation(start_x, start_y, width, height, annotation_type)

        # Add the annotation to the array
        state['annotations'].append(annotation)

        # Redraw the canvas
        draw_canvas(canvas, state['image'], state['annotations'])

    #

            # Define the draw annotation function
    def draw_annotation(canvas, start_x, start_y, end_x, end_y, annotation_type):
        canvas.clear()
        draw_canvas(canvas, state['image'], state['annotations'])
        width = np.abs(start_x - end_x)
        height = np.abs(start_y - end_y)
        if annotation_type == 'rect':
            canvas.draw_rect(start_x, start_y, width, height, stroke_color='red')
        elif annotation_type == 'circle':
            radius = np.sqrt(np.power(width, 2) + np.power(height, 2)) / 2
            center_x, center_y = start_x + width / 2, start_y + height / 2
            canvas.draw_circle(center_x, center_y, radius, stroke_color='red')

    # Define the annotation type dropdown event handler
    def annotation_type_changed(value):
        state['annotation_type'] = value

    # Define the download annotations button click event handler
    def download_annotations_clicked():
        # Define the csv headers
        headers = ['x', 'y', 'width', 'height', 'type']

        # Define the csv data
        rows = [[str(annotation.x), str(annotation.y), str(annotation.width), str(annotation.height), annotation.type]
                for annotation in state['annotations']]

        # Create the csv string
        csv_string = StringIO()
        csv_writer = csv.writer(csv_string)
        csv_writer.writerow(headers)
        for row in rows:
            csv_writer.writerow(row)

        # Download the csv file
        b64_csv = base64.b64encode(csv_string.getvalue().encode()).decode()
        href = f'data:text/csv;base64,{b64_csv}'
        download_link = f'<a href="{href}" download="annotations.csv">Download Annotations CSV</a>'
        gr.Interface.show(download_link)

    # Define the interface components
    image = gr.inputs.Image(label='Image')
    annotation_type = gr.inputs.Dropdown(ANNOTATION_TYPES, label='Annotation Type', default=ANNOTATION_TYPES[0], onchange=annotation_type_changed)
    download_annotations = gr.outputs.Button(label='Download Annotations', type='button', onclick=download_annotations_clicked)
    canvas = gr.outputs.Canvas(draw_event_handlers={
        'mousedown': canvas_mousedown,
        'mousemove': canvas_mousemove,
        'mouseup': canvas_mouseup
    })

    # Define the interface function
    def annotate_images(images):
        state['image'] = images[0]
        draw_canvas(canvas, state['image'], state['annotations'])
        return canvas, annotation_type, download_annotations

    # Create the interface
    interface = gr.Interface(annotate_images, inputs=image, outputs=[canvas, annotation_type, download_annotations], capture_session=True)

    return interface