COO-24 Add ability to view histograms

fits_viewer.py

@@ -9,15 +9,14 @@
 
 # Standard Library Imports
 import os
-import sys
-import glob
 
 from fits_viewer_ui import FITSViewerUI
 from image_utils import normalize_image, convert_to_qimage
 from viewfinder import ViewfinderPopup
+from histogram import Histogram
 
 # Third-Party Library Imports
-from PyQt5.QtWidgets import QMainWindow, QLabel, QVBoxLayout, QHBoxLayout, QPushButton, QSlider, QTextEdit, QFileDialog, QDesktopWidget
+from PyQt5.QtWidgets import QFileDialog, QDesktopWidget
 from PyQt5.QtCore import Qt, QSize, QEvent, QRect
 from PyQt5.QtGui import QPixmap, QImage
 from astropy.io import fits
@@ -43,16 +42,6 @@ def __init__(self):
         self.reset_image = None
         self.update_subtraction = False
         self.image_dir = None
-        self.setup_connections()
-
-    def setup_connections(self):
-        self.match_mode_action.toggled.connect(self.toggle_match_mode)
-        self.show_header_action.triggered.connect(self.show_header_tab)
-        self.slider.valueChanged.connect(self.adjust_contrast)
-        self.subtract_signal_action.triggered.connect(self.subtract_from_images)
-
-        # Add a connection to open the viewfinder popup
-        self.viewfinder_action.triggered.connect(self.open_viewfinder_popup)
 
     def open_fits_image(self):
         """
@@ -162,13 +151,13 @@ def update_result_label_size(self):
         """
         Adjust result_label to match the size of image_label1 and image_label2
         """
-        #if self.image_label1.pixmap():
-        size = self.image_label1.pixmap().size()
-        self.result_label.setFixedSize(size)
-        self.result_label.setPixmap(self.result_label.pixmap().scaled(size, Qt.KeepAspectRatio, Qt.SmoothTransformation))
-        # else:
-        #     # Default size if image_label1 has no pixmap
-        #     self.result_label.setFixedSize(1000, 500)  # or any default size you prefer
+        if self.image_label1.pixmap():
+            size = self.image_label1.pixmap().size()
+            self.result_label.setFixedSize(size)
+            self.result_label.setPixmap(self.result_label.pixmap().scaled(size, Qt.KeepAspectRatio, Qt.SmoothTransformation))
+        else:
+            # Default size if image_label1 has no pixmap
+            self.result_label.setFixedSize(1000, 500)  # or any default size you prefer
 
     def display_image(self, pixmap):
         """
@@ -612,3 +601,24 @@ def update_viewfinder(self):
 
             # Update the viewfinder popup with the cropped pixmap
             self.viewfinder_popup.set_image(cropped_pixmap)
+
+    def show_histogram(self):
+        """
+        Opens a histogram dialog for the cached images and result image.
+        """
+        if None in self.cached_images and self.result_image is None:
+            print("No images available for histogram.")
+            return
+
+        # Combine cached images and result image into one list
+        images_to_display = [img for img in self.cached_images if img is not None]
+        if self.result_image is not None:
+            images_to_display.append(QPixmap.fromImage(self.result_image))
+
+        if not images_to_display:
+            print("No valid images available for histogram.")
+            return
+
+        # Create and show the histogram dialog
+        histogram_dialog = Histogram(images_to_display, self)
+        histogram_dialog.exec_()

fits_viewer_ui.py

@@ -230,6 +230,10 @@ def create_tools_menu(self):
         self.show_header_action.triggered.connect(self.show_header_tab)
         self.tools_menu.addAction(self.show_header_action)
 
+        self.show_histogram_action = QAction("Histogram", self)
+        self.show_histogram_action.triggered.connect(self.show_histogram)
+        self.tools_menu.addAction(self.show_histogram_action)
+
     def create_view_menu(self):
         """
         Creates and configures the View menu.

histogram.py

@@ -0,0 +1,144 @@
+# -----------------------------------------------------------------------------
+# @file     histogram.py
+# @brief    A class for displaying histograms of images with interactive bin count adjustment and image navigation.
+# @author   Prakriti Gupta <[email protected]>
+# -----------------------------------------------------------------------------
+
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
+from PyQt5.QtWidgets import QDialog, QVBoxLayout, QSlider, QLabel, QPushButton, QHBoxLayout
+from PyQt5.QtCore import Qt
+from PyQt5.QtGui import QImage
+
+class Histogram(QDialog):
+    """
+    A class for displaying histograms of images with interactive bin count adjustment and image navigation.
+    """
+    def __init__(self, images, parent=None):
+        super().__init__(parent)
+        self.images = images  # List of QPixmap objects
+        self.current_image_index = 0  # Start with the first image
+
+        self.setWindowTitle("Image Histograms")
+
+        # Create layout
+        layout = QVBoxLayout()
+        self.setLayout(layout)
+
+        # Create a figure and axis for Matplotlib
+        self.figure, self.ax = plt.subplots(figsize=(8, 6))
+        self.canvas = FigureCanvas(self.figure)
+        layout.addWidget(self.canvas)
+
+        # Create a slider for adjusting the number of bins
+        self.slider = QSlider(Qt.Horizontal)
+        self.slider.setMinimum(1)
+        self.slider.setMaximum(256)
+        self.slider.setValue(256)
+        self.slider.setTickInterval(1)
+        self.slider.setTickPosition(QSlider.TicksBelow)
+        self.slider.valueChanged.connect(self.update_histogram)
+        layout.addWidget(self.slider)
+
+        # Create a label to display current bin count
+        self.bin_label = QLabel()
+        layout.addWidget(self.bin_label)
+
+        # Create navigation buttons
+        nav_layout = QHBoxLayout()
+        self.prev_button = QPushButton("Previous")
+        self.next_button = QPushButton("Next")
+        self.prev_button.clicked.connect(self.show_prev_image)
+        self.next_button.clicked.connect(self.show_next_image)
+        nav_layout.addWidget(self.prev_button)
+        nav_layout.addWidget(self.next_button)
+        layout.addLayout(nav_layout)
+
+        # Update initial histogram
+        self.update_histogram()
+
+    def update_histogram(self):
+        """
+        Updates the histogram plot based on the current bin count from the slider.
+        """
+        self.ax.clear()
+
+        # Get the current image data
+        image_data = self.pixmap_to_array(self.images[self.current_image_index])
+
+        # Flatten the image data to 1D
+        image_data_flat = image_data.flatten()
+
+        # Compute the histogram with the current number of bins
+        bin_count = self.slider.value()
+        histogram, bin_edges = np.histogram(image_data_flat, bins=bin_count, range=(np.min(image_data_flat), np.max(image_data_flat)))
+
+        # Plot the histogram with color-coded bins
+        colors = plt.cm.viridis(np.linspace(0, 1, bin_count))  # Use a colormap for colors
+        self.ax.bar(bin_edges[:-1], histogram, width=np.diff(bin_edges), color=colors, edgecolor='black')
+
+        # Set labels and title
+        self.ax.set_title('Histogram of Pixel Intensities')
+        self.ax.set_xlabel('Pixel Intensity')
+        self.ax.set_ylabel('Frequency')
+        self.ax.grid(True)
+
+        # Update the bin count label
+        self.bin_label.setText(f'Number of Bins: {bin_count}')
+
+        # Draw the canvas
+        self.canvas.draw()
+
+    def pixmap_to_array(self, pixmap):
+        """
+        Converts a QPixmap to a numpy array.
+        Handles both monochrome (grayscale), RGB, RGBA, and multispectral images.
+        """
+        # Convert QPixmap to QImage
+        image = pixmap.toImage()
+        width, height = image.width(), image.height()
+
+        # Convert to numpy array
+        ptr = image.bits()
+        if image.format() == QImage.Format_Grayscale8:
+            # Monochrome image (8-bit grayscale)
+            ptr.setsize(width * height)  # 1 byte per pixel
+            arr = np.array(ptr).reshape((height, width))
+        else:
+            # RGB or RGBA image (8-bit per channel)
+            ptr.setsize(width * height * 4)  # 4 bytes per pixel (RGBA)
+            arr = np.array(ptr).reshape((height, width, 4))  # RGBA image
+
+            # Handle different formats
+            if image.format() == QImage.Format_RGB888:
+                arr = arr[:, :, :3]  # Extract RGB channels
+            elif image.format() == QImage.Format_RGBA8888:
+                arr = arr[:, :, :3]  # Use RGB channels only
+            else:
+                # Handle multispectral images
+                if arr.shape[2] > 3:
+                    # Multispectral image with more than 3 channels
+                    # You can choose how to handle this, e.g., extract specific bands or process all bands
+                    # For demonstration, we will use all bands
+                    pass
+                else:
+                    raise ValueError("Unsupported image format")
+
+        return arr
+
+    def show_prev_image(self):
+        """
+        Shows the previous image in the list.
+        """
+        if self.current_image_index > 0:
+            self.current_image_index -= 1
+            self.update_histogram()
+
+    def show_next_image(self):
+        """
+        Shows the next image in the list.
+        """
+        if self.current_image_index < len(self.images) - 1:
+            self.current_image_index += 1
+            self.update_histogram()

requirements.txt

@@ -1,3 +1,4 @@
 astropy
 numpy
 PyQt5
+matplotlib

viewfinder.py

@@ -1,5 +1,5 @@
 # -----------------------------------------------------------------------------
-# @file     fits_viewer_ui.py
+# @file     viewfinder.py
 # @brief    A dialog window for displaying and selecting between different image views. 
 # @author   Prakriti Gupta <[email protected]>
 # -----------------------------------------------------------------------------