Files
object-segmentation/src/gui/widgets/image_display_widget.py
2025-12-10 16:55:28 +02:00

283 lines
8.8 KiB
Python

"""
Image display widget with zoom functionality for the microscopy object detection application.
Reusable widget for displaying images with zoom controls.
"""
from PySide6.QtWidgets import QWidget, QVBoxLayout, QLabel, QScrollArea
from PySide6.QtGui import QPixmap, QImage, QKeyEvent
from PySide6.QtCore import Qt, QEvent, Signal
from pathlib import Path
import numpy as np
from src.utils.image import Image, ImageLoadError
from src.utils.logger import get_logger
logger = get_logger(__name__)
class ImageDisplayWidget(QWidget):
"""
Reusable widget for displaying images with zoom functionality.
Features:
- Display images from Image objects
- Zoom in/out with mouse wheel
- Zoom in/out with +/- keyboard keys
- Reset zoom with Ctrl+0
- Scroll area for large images
Signals:
zoom_changed: Emitted when zoom level changes (float zoom_scale)
"""
zoom_changed = Signal(float) # Emitted when zoom level changes
def __init__(self, parent=None):
"""
Initialize the image display widget.
Args:
parent: Parent widget
"""
super().__init__(parent)
self.current_image = None
self.original_pixmap = None # Store original pixmap for zoom
self.zoom_scale = 1.0 # Current zoom scale
self.zoom_min = 0.1 # Minimum zoom (10%)
self.zoom_max = 10.0 # Maximum zoom (1000%)
self.zoom_step = 0.1 # Zoom step for +/- keys
self.zoom_wheel_step = 0.15 # Zoom step for mouse wheel
self._setup_ui()
def _setup_ui(self):
"""Setup user interface."""
layout = QVBoxLayout()
layout.setContentsMargins(0, 0, 0, 0)
# Scroll area for image
self.scroll_area = QScrollArea()
self.scroll_area.setWidgetResizable(True)
self.scroll_area.setMinimumHeight(400)
self.image_label = QLabel("No image loaded")
self.image_label.setAlignment(Qt.AlignCenter)
self.image_label.setStyleSheet(
"QLabel { background-color: #2b2b2b; color: #888; }"
)
self.image_label.setScaledContents(False)
# Enable mouse tracking for wheel events
self.image_label.setMouseTracking(True)
self.scroll_area.setWidget(self.image_label)
# Install event filter to capture wheel events on scroll area
self.scroll_area.viewport().installEventFilter(self)
layout.addWidget(self.scroll_area)
self.setLayout(layout)
# Set focus policy to receive keyboard events
self.setFocusPolicy(Qt.StrongFocus)
def load_image(self, image: Image):
"""
Load and display an image.
Args:
image: Image object to display
Raises:
ImageLoadError: If image cannot be displayed
"""
self.current_image = image
# Reset zoom when loading new image
self.zoom_scale = 1.0
# Convert to QPixmap and display
self._display_image()
logger.debug(f"Loaded image into display widget: {image.width}x{image.height}")
def clear(self):
"""Clear the displayed image."""
self.current_image = None
self.original_pixmap = None
self.zoom_scale = 1.0
self.image_label.setText("No image loaded")
self.image_label.setPixmap(QPixmap())
logger.debug("Cleared image display")
def _display_image(self):
"""Display the current image in the image label."""
if self.current_image is None:
return
try:
# Get RGB image data
if self.current_image.channels == 3:
image_data = self.current_image.get_rgb()
height, width, channels = image_data.shape
else:
image_data = self.current_image.get_grayscale()
height, width = image_data.shape
channels = 1
# Ensure data is contiguous for proper QImage display
image_data = np.ascontiguousarray(image_data)
# Use actual stride from numpy array for correct display
bytes_per_line = image_data.strides[0]
qimage = QImage(
image_data.data,
width,
height,
bytes_per_line,
self.current_image.qtimage_format,
).copy() # Copy to ensure Qt owns its memory after this scope
# Convert to pixmap
pixmap = QPixmap.fromImage(qimage)
# Store original pixmap for zooming
self.original_pixmap = pixmap
# Apply zoom and display
self._apply_zoom()
except Exception as e:
logger.error(f"Error displaying image: {e}")
raise ImageLoadError(f"Failed to display image: {str(e)}")
def _apply_zoom(self):
"""Apply current zoom level to the displayed image."""
if self.original_pixmap is None:
return
# Calculate scaled size
scaled_width = int(self.original_pixmap.width() * self.zoom_scale)
scaled_height = int(self.original_pixmap.height() * self.zoom_scale)
# Scale pixmap
scaled_pixmap = self.original_pixmap.scaled(
scaled_width,
scaled_height,
Qt.KeepAspectRatio,
(
Qt.SmoothTransformation
if self.zoom_scale >= 1.0
else Qt.FastTransformation
),
)
# Display in label
self.image_label.setPixmap(scaled_pixmap)
self.image_label.setScaledContents(False)
self.image_label.adjustSize()
# Emit zoom changed signal
self.zoom_changed.emit(self.zoom_scale)
def zoom_in(self):
"""Zoom in on the image."""
if self.original_pixmap is None:
return
new_scale = self.zoom_scale + self.zoom_step
if new_scale <= self.zoom_max:
self.zoom_scale = new_scale
self._apply_zoom()
logger.debug(f"Zoomed in to {int(self.zoom_scale * 100)}%")
def zoom_out(self):
"""Zoom out from the image."""
if self.original_pixmap is None:
return
new_scale = self.zoom_scale - self.zoom_step
if new_scale >= self.zoom_min:
self.zoom_scale = new_scale
self._apply_zoom()
logger.debug(f"Zoomed out to {int(self.zoom_scale * 100)}%")
def reset_zoom(self):
"""Reset zoom to 100%."""
if self.original_pixmap is None:
return
self.zoom_scale = 1.0
self._apply_zoom()
logger.debug("Reset zoom to 100%")
def set_zoom(self, scale: float):
"""
Set zoom to a specific scale.
Args:
scale: Zoom scale (1.0 = 100%)
"""
if self.original_pixmap is None:
return
# Clamp to min/max
scale = max(self.zoom_min, min(self.zoom_max, scale))
self.zoom_scale = scale
self._apply_zoom()
logger.debug(f"Set zoom to {int(self.zoom_scale * 100)}%")
def get_zoom_percentage(self) -> int:
"""
Get current zoom level as percentage.
Returns:
Zoom level as integer percentage (e.g., 100 for 100%)
"""
return int(self.zoom_scale * 100)
def keyPressEvent(self, event: QKeyEvent):
"""Handle keyboard events for zooming."""
if event.key() in (Qt.Key_Plus, Qt.Key_Equal):
# + or = key (= is the unshifted + on many keyboards)
self.zoom_in()
event.accept()
elif event.key() == Qt.Key_Minus:
# - key
self.zoom_out()
event.accept()
elif event.key() == Qt.Key_0 and event.modifiers() == Qt.ControlModifier:
# Ctrl+0 to reset zoom
self.reset_zoom()
event.accept()
else:
super().keyPressEvent(event)
def eventFilter(self, obj, event: QEvent) -> bool:
"""Event filter to capture wheel events for zooming."""
if event.type() == QEvent.Wheel:
wheel_event = event
if self.original_pixmap is not None:
# Get wheel angle delta
delta = wheel_event.angleDelta().y()
# Zoom in/out based on wheel direction
if delta > 0:
# Scroll up = zoom in
new_scale = self.zoom_scale + self.zoom_wheel_step
if new_scale <= self.zoom_max:
self.zoom_scale = new_scale
self._apply_zoom()
else:
# Scroll down = zoom out
new_scale = self.zoom_scale - self.zoom_wheel_step
if new_scale >= self.zoom_min:
self.zoom_scale = new_scale
self._apply_zoom()
return True # Event handled
return super().eventFilter(obj, event)