diff --git a/src/GUI.py b/src/GUI.py
index 20718a4..b930786 100644
--- a/src/GUI.py
+++ b/src/GUI.py
@@ -1,75 +1,146 @@
-import tkinter as tk
-from tkinter import filedialog
-from PIL import ImageTk
-from ImageContainer import ImageContainer
-from ImageManipulation.ManipulationList import *
-
-
-class GUI:
-    """The GUI class responsible for the main application GUI.
-
-    @warning This class is a singleton.
-    """
-    _instance = None
-
-    # If the GUI has been initialised.
-    _isInitialised = False
-
-    _currentImage = None
-
-    def __new__(cls):
-        if cls._instance is None:
-            cls._instance = super(GUI, cls).__new__(cls)
-        return cls._instance
-
-    def initialise(self):
-        """Initialise the GUI."""
-
-        if self._isInitialised:
-            return
-        else:
-            self._isInitialised = True
-
-        # Main window
-        root = tk.Tk()
-        root.title("Image Viewer")
-        root.geometry("800x600")
-        root.config(bg="white")
-        icon = tk.PhotoImage(file='icon.png')
-        root.tk.call('wm', 'iconphoto', root._w, icon)
-        root.minsize(800, 600)
-
-        # Menus
-        menu = tk.Menu(root)
-        root.config(menu=menu)
-        file_menu = tk.Menu(menu, tearoff=0)
-        menu.add_cascade(label="File", menu=file_menu)
-        file_menu.add_command(label="Open Image", command=lambda: self._openImage())
-        file_menu.add_command(label="Save Image", command=lambda: _save_image(OPENED_IMAGE))
-        file_menu.add_command(label="Exit", command=root.quit)
-
-
-        test_menu = tk.Menu(menu, tearoff=0)
-        menu.add_cascade(label="Filters", menu=test_menu)
-        for manipulation in GetImageManipulationList():
-            test_menu.add_command(label=manipulation.getManipulationName(), command=lambda: manipulation.manipulateImage())
-
-        # Frame to hold image
-        imgframe = tk.Frame(root, width=500, height=500, bg="lightgray", relief="sunken", bd=2)
-        imgframe.pack(side="top", pady=10)
-
-        # Label to display image
-        image_label = tk.Label(imgframe, width=500, height=500, bg="white")
-        image_label.pack(expand=True)
-
-        root.mainloop()
-
-    def _openImage(self) -> None:
-        file_path = filedialog.askopenfilename(
-            filetypes=[("Image files", "*.jpg *.jpeg *.png *.gif *.bmp")]
-        )
-        if not file_path:
-            return
-
-        self._currentImage = ImageContainer()
-        self._currentImage.loadImage(file_path)
\ No newline at end of file
+import tkinter as tk
+from tkinter import filedialog
+from PIL import ImageTk
+from ImageContainer import ImageContainer
+from ImageManipulation.ManipulationList import *
+from functools import partial
+
+
+class GUI:
+    """The GUI class responsible for the main application GUI.
+
+    @warning This class is a singleton.
+    """
+    _instance = None
+
+    # If the GUI has been initialised.
+    _isInitialised = False
+
+    _currentImage = None
+
+    def __new__(cls):
+        if cls._instance is None:
+            cls._instance = super(GUI, cls).__new__(cls)
+        return cls._instance
+
+    def initialise(self):
+        """Initialise the GUI."""
+
+        if self._isInitialised:
+            return
+        else:
+            self._isInitialised = True
+
+        # Main window
+        root = tk.Tk()
+        root.title("Image Viewer")
+        root.geometry("800x600")
+        root.config(bg="white")
+        icon = tk.PhotoImage(file='icon.png')
+        root.tk.call('wm', 'iconphoto', root._w, icon)
+        root.minsize(800, 600)
+
+        # Menus
+        menu = tk.Menu(root)
+        root.config(menu=menu)
+        file_menu = tk.Menu(menu, tearoff=0)
+        menu.add_cascade(label="File", menu=file_menu)
+        file_menu.add_command(label="Open Image", command=lambda: self._openImage())
+        file_menu.add_command(label="Save Image", command=lambda: self._saveImage())
+        file_menu.add_command(label="Exit", command=root.quit)
+
+        edit_menu = tk.Menu(menu, tearoff=0)
+        menu.add_cascade(label="Edit", menu=edit_menu)
+        edit_menu.add_command(label="Undo", accelerator="Ctrl+Z", command=lambda: self._undo())
+
+
+        test_menu = tk.Menu(menu, tearoff=0)
+        menu.add_cascade(label="Filters", menu=test_menu)
+        for manipulation in GetImageManipulationList():
+            test_menu.add_command(
+                label=manipulation.getManipulationName(),
+                command=partial(self._applyManipulation, manipulation)
+            )
+
+        # Manual Test menu listing all manipulations explicitly
+        manual_menu = tk.Menu(menu, tearoff=0)
+        menu.add_cascade(label="Test", menu=manual_menu)
+        manual_menu.add_command(label="Padding", command=partial(self._applyManipulation, Padding(), {"border_width": 50}))
+        manual_menu.add_command(label="Crop", command=partial(self._applyManipulation, CropImage()))
+        manual_menu.add_command(label="Resize", command=partial(self._applyManipulation, ResizeImage(), {"width": 200, "height": 200}))
+        manual_menu.add_command(label="Copy", command=partial(self._applyManipulation, CopyImage()))
+        manual_menu.add_command(label="Greyscale", command=partial(self._applyManipulation, Grayscale()))
+        manual_menu.add_command(label="HSV", command=partial(self._applyManipulation, HSV()))
+        manual_menu.add_command(label="Hue Shifted", command=partial(self._applyManipulation, HueShift(), {"hue": 50}))
+        manual_menu.add_command(label="Smoothed", command=partial(self._applyManipulation, BoxBlur(), {"ksize": 15}))
+        manual_menu.add_command(label="Rotated", command=partial(self._applyManipulation, RotateImage(), {"angle": 90}))
+        manual_menu.add_command(label="Flip (Horizontal)", command=partial(self._applyManipulation, FlipImage(), {"mode": "horizontal"}))
+        manual_menu.add_command(label="Flip (Vertical)", command=partial(self._applyManipulation, FlipImage(), {"mode": "vertical"}))
+        manual_menu.add_command(label="Color Adjust", command=partial(self._applyManipulation, ColorAdjust(), {"brightness": 10, "contrast": 1.2, "saturation": 1.1}))
+        manual_menu.add_command(label="Gaussian Blur", command=partial(self._applyManipulation, GaussianBlur(), {"ksize": 5}))
+        manual_menu.add_command(label="Sobel Edge", command=partial(self._applyManipulation, SobelEdge(), {"dx": 1, "dy": 0, "ksize": 3}))
+        manual_menu.add_command(label="Binary Threshold", command=partial(self._applyManipulation, BinaryThreshold(), {"thresh": 127}))
+        manual_menu.add_command(label="Histogram Threshold", command=partial(self._applyManipulation, HistogramThreshold()))
+
+        # Frame to hold image
+        imgframe = tk.Frame(root, width=500, height=500, bg="lightgray", relief="sunken", bd=2)
+        imgframe.pack(side="top", pady=10)
+
+        # Label to display image
+        self._imageLabel = tk.Label(imgframe, width=500, height=500, bg="white")
+        self._imageLabel.pack(expand=True)
+
+        self._root = root
+
+        # Key bindings
+        root.bind_all('<Control-z>', lambda event: self._undo())
+
+        root.mainloop()
+
+    def _openImage(self) -> None:
+        file_path = filedialog.askopenfilename(
+            filetypes=[("Image files", "*.jpg *.jpeg *.png *.gif *.bmp")]
+        )
+        if not file_path:
+            return
+
+        self._currentImage = ImageContainer()
+        self._currentImage.loadImage(file_path)
+        self._renderCurrentImage()
+
+    def _renderCurrentImage(self) -> None:
+        if self._currentImage is None or self._currentImage.getImage() is None:
+            return
+        pil_img = self._currentImage.getImage()
+        width, height = pil_img.size
+        tk_img = ImageTk.PhotoImage(pil_img)
+        # Keep reference to avoid garbage collection
+        self._imageLabel.image = tk_img
+        self._imageLabel.config(image=tk_img, width=width, height=height)
+
+    def _applyManipulation(self, manipulation, params: dict | None = None) -> None:
+        if self._currentImage is None:
+            return
+        # Take undo snapshot
+        self._currentImage.snapshot()
+        if params is None:
+            # default demo params for crop
+            params = {"width": 200, "height": 200}
+        manipulation.manipulateImage(self._currentImage, params)
+        self._renderCurrentImage()
+
+    def _saveImage(self) -> None:
+        if self._currentImage is None or self._currentImage.getImage() is None:
+            return
+        path = filedialog.asksaveasfilename(defaultextension=".png", filetypes=[
+            ("PNG", "*.png"), ("JPEG", "*.jpg;*.jpeg"), ("Bitmap", "*.bmp"), ("All Files", "*.*")
+        ])
+        if not path:
+            return
+        self._currentImage.saveImage(path)
+
+    def _undo(self) -> None:
+        if self._currentImage is None:
+            return
+        self._currentImage.undo()
+        self._renderCurrentImage()
\ No newline at end of file
diff --git a/src/ImageContainer.py b/src/ImageContainer.py
index 4f948eb..9004d99 100644
--- a/src/ImageContainer.py
+++ b/src/ImageContainer.py
@@ -1,25 +1,51 @@
-import cv2
-from PIL import Image, ImageTk
-
-class ImageContainer:
-    _imageData = None
-    _path = None
-
-    def loadImage(self, path: str) -> None:
-        """ Load image file from the path.
-
-        :param path: Path to the image file.
-        """
-        imgcv2 = cv2.imread(path)
-        height, width, channels = imgcv2.shape
-
-        # Open and resize image (optional)
-        _imageData = Image.open(path)
-        _imageData = _imageData.resize((height, width), Image.LANCZOS)  # Resize to fit frame
-
-        _path = path
-
-        print("Opened image:", path)
-
-    def getDimensions(self) -> tuple[int,int]:
-        return self._imageData.shape
\ No newline at end of file
+import cv2
+from PIL import Image, ImageTk
+
+class ImageContainer:
+    _imageData = None
+    _path = None
+    _history = None
+
+    def loadImage(self, path: str) -> None:
+        """ Load image file from the path.
+
+        :param path: Path to the image file.
+        """
+        imgcv2 = cv2.imread(path)
+        height, width, channels = imgcv2.shape
+
+        # Open and resize image (optional)
+        self._imageData = Image.open(path)
+        # PIL expects (width, height)
+        self._imageData = self._imageData.resize((width, height), Image.LANCZOS)
+
+        self._path = path
+        self._history = []
+
+        print("Opened image:", path)
+
+    def getDimensions(self) -> tuple[int,int]:
+        # PIL Image.size returns (width, height)
+        return self._imageData.size if self._imageData is not None else (0, 0)
+
+    def getImage(self) -> Image:
+        return self._imageData
+
+    def saveImage(self, path: str) -> None:
+        if self._imageData is not None:
+            self._imageData.save(path)
+
+    def snapshot(self) -> None:
+        """Push a copy of current image to history for undo."""
+        if self._imageData is None:
+            return
+        # Ensure a deep copy (PIL copy is sufficient)
+        self._history.append(self._imageData.copy())
+        # Cap history size to avoid memory blow-up
+        if len(self._history) > 20:
+            self._history.pop(0)
+
+    def undo(self) -> None:
+        if not self._history:
+            return
+        self._imageData = self._history.pop()
\ No newline at end of file
diff --git a/src/ImageManipulation/BoxBlur.py b/src/ImageManipulation/BoxBlur.py
new file mode 100644
index 0000000..f821151
--- /dev/null
+++ b/src/ImageManipulation/BoxBlur.py
@@ -0,0 +1,28 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class BoxBlur(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Box Blur"
+
+    def getParameters(self) -> List[str]:
+        return ["ksize"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        k = 15
+        if isinstance(parameters, dict) and parameters.get("ksize"):
+            k = int(parameters.get("ksize"))
+        if k % 2 == 0:
+            k += 1
+        blurred = cv2.blur(cv_img, (k, k))
+        image._imageData = cv2_to_pil(blurred)
+
+
diff --git a/src/ImageManipulation/ColorAdjust.py b/src/ImageManipulation/ColorAdjust.py
new file mode 100644
index 0000000..bf63be5
--- /dev/null
+++ b/src/ImageManipulation/ColorAdjust.py
@@ -0,0 +1,45 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+import numpy as np
+
+
+class ColorAdjust(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Color Adjust"
+
+    def getParameters(self) -> List[str]:
+        return ["brightness", "contrast", "saturation"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+
+        brightness = 0.0
+        contrast = 1.0
+        saturation = 1.0
+
+        if isinstance(parameters, dict):
+            if parameters.get("brightness") is not None:
+                brightness = float(parameters.get("brightness"))  # -100..100 (additive)
+            if parameters.get("contrast") is not None:
+                contrast = float(parameters.get("contrast"))      # 0.0..3.0 (multiplicative)
+            if parameters.get("saturation") is not None:
+                saturation = float(parameters.get("saturation"))  # 0.0..3.0 (multiplicative)
+
+        # Apply brightness/contrast on BGR
+        adjusted = cv2.convertScaleAbs(cv_img, alpha=contrast, beta=brightness)
+
+        # Adjust saturation in HSV
+        hsv = cv2.cvtColor(adjusted, cv2.COLOR_BGR2HSV).astype(np.float32)
+        h, s, v = cv2.split(hsv)
+        s = np.clip(s * saturation, 0, 255)
+        hsv = cv2.merge([h, s, v]).astype(np.uint8)
+        result = cv2.cvtColor(hsv, cv2.COLOR_HSV2BGR)
+
+        image._imageData = cv2_to_pil(result)
+
diff --git a/src/ImageManipulation/CopyImage.py b/src/ImageManipulation/CopyImage.py
new file mode 100644
index 0000000..d552d61
--- /dev/null
+++ b/src/ImageManipulation/CopyImage.py
@@ -0,0 +1,23 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import numpy as np
+
+
+class CopyImage(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Copy"
+
+    def getParameters(self) -> List[str]:
+        return []
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        # Deep copy using numpy array roundtrip to ensure a new buffer
+        pil_img = image.getImage()
+        arr = np.array(pil_img)
+        image._imageData = pil_img.copy()
+
+
diff --git a/src/ImageManipulation/CropImage.py b/src/ImageManipulation/CropImage.py
index 0887a14..18d25cf 100644
--- a/src/ImageManipulation/CropImage.py
+++ b/src/ImageManipulation/CropImage.py
@@ -1,39 +1,69 @@
-from ImageManipulation.ImageManipulation import ImageManipulation
-from ImageContainer import ImageContainer
-from typing import Any, List
-
-
-class CropImage(ImageManipulation):
-    """Concrete implementation for cropping images."""
-
-    def __init__(self):
-        # You can initialize any instance variables here
-        self.manipulation_name = "Crop"
-
-    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
-        """
-        Manipulate the given image using the provided parameters.
-
-        Args:
-            image: The image to manipulate
-            parameters: Parameters for the manipulation (e.g., crop coordinates)
-        """
-        pass
-
-    def getParameters(self) -> List[str]:
-        """
-        Get the list of parameters required for cropping.
-
-        Returns:
-            List of parameter names
-        """
-        return ["width", "height"]
-
-    def getManipulationName(self) -> str:
-        """
-        Get the name of this manipulation operation.
-
-        Returns:
-            The name of the manipulation
-        """
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from PIL import Image
+
+
+class CropImage(ImageManipulation):
+    """Concrete implementation for cropping images."""
+
+    def __init__(self):
+        # You can initialize any instance variables here
+        self.manipulation_name = "Crop"
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        """
+        Manipulate the given image using the provided parameters.
+
+        Args:
+            image: The image to manipulate
+            parameters: Parameters for the manipulation (e.g., crop coordinates)
+        """
+        if image is None or getattr(image, "_imageData", None) is None:
+            return
+
+        pil_image = image._imageData
+
+        # If parameters provided as dict with width/height, do centered crop
+        if isinstance(parameters, dict) and "width" in parameters and "height" in parameters:
+            target_width = int(parameters["width"]) if parameters["width"] is not None else None
+            target_height = int(parameters["height"]) if parameters["height"] is not None else None
+            if target_width is None or target_height is None:
+                return
+            img_width, img_height = pil_image.size
+            crop_width = min(target_width, img_width)
+            crop_height = min(target_height, img_height)
+            left = (img_width - crop_width) // 2
+            top = (img_height - crop_height) // 2
+            right = left + crop_width
+            bottom = top + crop_height
+        else:
+            # Default: trim margins similar to demo in root main.py
+            img_width, img_height = pil_image.size
+            left = 80
+            top = 80
+            right = max(0, img_width - 130)
+            bottom = max(0, img_height - 130)
+            if right <= left or bottom <= top:
+                return
+
+        cropped = pil_image.crop((left, top, right, bottom))
+        image._imageData = cropped
+
+    def getParameters(self) -> List[str]:
+        """
+        Get the list of parameters required for cropping.
+
+        Returns:
+            List of parameter names
+        """
+        return ["width", "height"]
+
+    def getManipulationName(self) -> str:
+        """
+        Get the name of this manipulation operation.
+
+        Returns:
+            The name of the manipulation
+        """
         return "Crop Image"
\ No newline at end of file
diff --git a/src/ImageManipulation/Filters.py b/src/ImageManipulation/Filters.py
new file mode 100644
index 0000000..1675218
--- /dev/null
+++ b/src/ImageManipulation/Filters.py
@@ -0,0 +1,84 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class GaussianBlur(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Gaussian Blur"
+
+    def getParameters(self) -> List[str]:
+        return ["ksize"]  # odd int
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        ksize = 5
+        if isinstance(parameters, dict) and parameters.get("ksize"):
+            ksize = int(parameters.get("ksize"))
+        if ksize % 2 == 0:
+            ksize += 1
+        cv_img = pil_to_cv2(pil_img)
+        blurred = cv2.GaussianBlur(cv_img, (ksize, ksize), 0)
+        image._imageData = cv2_to_pil(blurred)
+
+
+class SobelEdge(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Sobel Edge"
+
+    def getParameters(self) -> List[str]:
+        return ["dx", "dy", "ksize"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        gray = cv2.cvtColor(cv_img, cv2.COLOR_BGR2GRAY)
+        dx = int(parameters.get("dx", 1)) if isinstance(parameters, dict) else 1
+        dy = int(parameters.get("dy", 0)) if isinstance(parameters, dict) else 0
+        ksize = int(parameters.get("ksize", 3)) if isinstance(parameters, dict) else 3
+        sobel = cv2.Sobel(gray, cv2.CV_64F, dx, dy, ksize=ksize)
+        abs_sobel = cv2.convertScaleAbs(sobel)
+        image._imageData = cv2_to_pil(abs_sobel)
+
+
+class BinaryThreshold(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Binary Threshold"
+
+    def getParameters(self) -> List[str]:
+        return ["thresh"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        gray = cv2.cvtColor(cv_img, cv2.COLOR_BGR2GRAY)
+        thresh_val = int(parameters.get("thresh", 127)) if isinstance(parameters, dict) else 127
+        _, thresh = cv2.threshold(gray, thresh_val, 255, cv2.THRESH_BINARY)
+        image._imageData = cv2_to_pil(thresh)
+
+
+class HistogramThreshold(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Histogram Threshold"
+
+    def getParameters(self) -> List[str]:
+        return []
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        gray = cv2.cvtColor(cv_img, cv2.COLOR_BGR2GRAY)
+        # Otsu's threshold as histogram-based method
+        _, otsu = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
+        image._imageData = cv2_to_pil(otsu)
+
diff --git a/src/ImageManipulation/FlipImage.py b/src/ImageManipulation/FlipImage.py
new file mode 100644
index 0000000..c78cdc8
--- /dev/null
+++ b/src/ImageManipulation/FlipImage.py
@@ -0,0 +1,26 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class FlipImage(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Flip"
+
+    def getParameters(self) -> List[str]:
+        return ["mode"]  # horizontal|vertical
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        mode = "horizontal"
+        if isinstance(parameters, dict) and parameters.get("mode") in ("horizontal", "vertical"):
+            mode = parameters.get("mode")
+        cv_img = pil_to_cv2(pil_img)
+        flip_code = 1 if mode == "horizontal" else 0
+        flipped = cv2.flip(cv_img, flip_code)
+        image._imageData = cv2_to_pil(flipped)
+
diff --git a/src/ImageManipulation/Grayscale.py b/src/ImageManipulation/Grayscale.py
new file mode 100644
index 0000000..a54c239
--- /dev/null
+++ b/src/ImageManipulation/Grayscale.py
@@ -0,0 +1,23 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class Grayscale(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Grayscale"
+
+    def getParameters(self) -> List[str]:
+        return []
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        gray = cv2.cvtColor(cv_img, cv2.COLOR_BGR2GRAY)
+        image._imageData = cv2_to_pil(gray)
+
+
diff --git a/src/ImageManipulation/HSV.py b/src/ImageManipulation/HSV.py
new file mode 100644
index 0000000..d7c4897
--- /dev/null
+++ b/src/ImageManipulation/HSV.py
@@ -0,0 +1,23 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class HSV(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "HSV"
+
+    def getParameters(self) -> List[str]:
+        return []
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        hsv = cv2.cvtColor(cv_img, cv2.COLOR_BGR2HSV)
+        image._imageData = cv2_to_pil(hsv)
+
+
diff --git a/src/ImageManipulation/HueShift.py b/src/ImageManipulation/HueShift.py
new file mode 100644
index 0000000..8ec1a90
--- /dev/null
+++ b/src/ImageManipulation/HueShift.py
@@ -0,0 +1,32 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+import numpy as np
+
+
+class HueShift(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Hue Shift"
+
+    def getParameters(self) -> List[str]:
+        return ["hue"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        hsv = cv2.cvtColor(cv_img, cv2.COLOR_BGR2HSV).astype(np.uint8)
+        hue_delta = 50
+        if isinstance(parameters, dict) and parameters.get("hue") is not None:
+            hue_delta = int(parameters.get("hue"))
+        h, s, v = cv2.split(hsv)
+        # OpenCV H range is [0,179]; wrap around using modulo
+        h = ((h.astype(np.int16) + hue_delta) % 180).astype(np.uint8)
+        hsv_shifted = cv2.merge([h, s, v])
+        bgr = cv2.cvtColor(hsv_shifted, cv2.COLOR_HSV2BGR)
+        image._imageData = cv2_to_pil(bgr)
+
+
diff --git a/src/ImageManipulation/ImageManipulation.py b/src/ImageManipulation/ImageManipulation.py
index 909cd3c..caef028 100644
--- a/src/ImageManipulation/ImageManipulation.py
+++ b/src/ImageManipulation/ImageManipulation.py
@@ -1,39 +1,38 @@
-from abc import ABC, abstractmethod
-from typing import Any
-
-from ImageContainer import ImageContainer
-
-
-class ImageManipulation(ABC):
-    """Abstract base class for image manipulation operations."""
-
-    @abstractmethod
-    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
-        """
-        Manipulate the given image using the provided parameters.
-
-        Args:
-            image: The image to manipulate
-            parameters: Parameters for the manipulation
-        """
-        pass
-
-    @abstractmethod
-    def getParameters(self) -> list[str]:
-        """
-        Get the list of parameters required for this manipulation.
-
-        Returns:
-            List of parameter names
-        """
-        pass
-
-    @abstractmethod
-    def getManipulationName(self) -> str:
-        """
-        Get the name of this manipulation operation.
-
-        Returns:
-            The name of the manipulation
-        """
-        pass
+from abc import ABC, abstractmethod
+from typing import Any
+from ImageContainer import ImageContainer
+
+
+class ImageManipulation(ABC):
+    """Abstract base class for image manipulation operations."""
+
+    @abstractmethod
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        """
+        Manipulate the given image using the provided parameters.
+
+        Args:
+            image: The image to manipulate
+            parameters: Parameters for the manipulation
+        """
+        pass
+
+    @abstractmethod
+    def getParameters(self) -> list[str]:
+        """
+        Get the list of parameters required for this manipulation.
+
+        Returns:
+            List of parameter names
+        """
+        pass
+
+    @abstractmethod
+    def getManipulationName(self) -> str:
+        """
+        Get the name of this manipulation operation.
+
+        Returns:
+            The name of the manipulation
+        """
+        pass
diff --git a/src/ImageManipulation/ManipulationList.py b/src/ImageManipulation/ManipulationList.py
index dcc9d23..3cee483 100644
--- a/src/ImageManipulation/ManipulationList.py
+++ b/src/ImageManipulation/ManipulationList.py
@@ -1,4 +1,31 @@
-from ImageManipulation.CropImage import *
-
-def GetImageManipulationList() -> list:
-    return [CropImage()]
+from .CropImage import CropImage
+from .ResizeImage import ResizeImage
+from .RotateImage import RotateImage
+from .FlipImage import FlipImage
+from .ColorAdjust import ColorAdjust
+from .Filters import GaussianBlur, SobelEdge, BinaryThreshold, HistogramThreshold
+from .Padding import Padding
+from .Grayscale import Grayscale
+from .HSV import HSV
+from .HueShift import HueShift
+from .BoxBlur import BoxBlur
+from .CopyImage import CopyImage
+
+def GetImageManipulationList() -> list:
+    return [
+        CropImage(),
+        ResizeImage(),
+        RotateImage(),
+        FlipImage(),
+        ColorAdjust(),
+        Padding(),
+        Grayscale(),
+        HSV(),
+        HueShift(),
+        BoxBlur(),
+        CopyImage(),
+        GaussianBlur(),
+        SobelEdge(),
+        BinaryThreshold(),
+        HistogramThreshold(),
+    ]
\ No newline at end of file
diff --git a/src/ImageManipulation/Padding.py b/src/ImageManipulation/Padding.py
new file mode 100644
index 0000000..1dbd7ea
--- /dev/null
+++ b/src/ImageManipulation/Padding.py
@@ -0,0 +1,33 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class Padding(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Padding"
+
+    def getParameters(self) -> List[str]:
+        return ["border_width"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        cv_img = pil_to_cv2(pil_img)
+        border_width = 50
+        if isinstance(parameters, dict) and parameters.get("border_width") is not None:
+            border_width = int(parameters.get("border_width"))
+        padded = cv2.copyMakeBorder(
+            cv_img,
+            top=border_width,
+            bottom=border_width,
+            left=border_width,
+            right=border_width,
+            borderType=cv2.BORDER_REFLECT,
+        )
+        image._imageData = cv2_to_pil(padded)
+
+
diff --git a/src/ImageManipulation/ResizeImage.py b/src/ImageManipulation/ResizeImage.py
new file mode 100644
index 0000000..561e57f
--- /dev/null
+++ b/src/ImageManipulation/ResizeImage.py
@@ -0,0 +1,31 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class ResizeImage(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Resize"
+
+    def getParameters(self) -> List[str]:
+        return ["width", "height"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        width = None
+        height = None
+        if isinstance(parameters, dict):
+            width = parameters.get("width")
+            height = parameters.get("height")
+        if not width or not height:
+            # Default: scale to half
+            w, h = pil_img.size
+            width, height = max(1, w // 2), max(1, h // 2)
+        cv_img = pil_to_cv2(pil_img)
+        resized = cv2.resize(cv_img, (int(width), int(height)), interpolation=cv2.INTER_AREA)
+        image._imageData = cv2_to_pil(resized)
+
diff --git a/src/ImageManipulation/RotateImage.py b/src/ImageManipulation/RotateImage.py
new file mode 100644
index 0000000..3c4f973
--- /dev/null
+++ b/src/ImageManipulation/RotateImage.py
@@ -0,0 +1,28 @@
+from .ImageManipulation import ImageManipulation
+from ImageContainer import ImageContainer
+from typing import Any, List
+from utils.image_utils import pil_to_cv2, cv2_to_pil
+import cv2
+
+
+class RotateImage(ImageManipulation):
+    def getManipulationName(self) -> str:
+        return "Rotate"
+
+    def getParameters(self) -> List[str]:
+        return ["angle"]
+
+    def manipulateImage(self, image: ImageContainer, parameters: Any) -> None:
+        if image is None or image.getImage() is None:
+            return
+        pil_img = image.getImage()
+        angle = 90
+        if isinstance(parameters, dict) and parameters.get("angle") is not None:
+            angle = int(parameters.get("angle"))
+        cv_img = pil_to_cv2(pil_img)
+        (h, w) = cv_img.shape[:2]
+        center = (w // 2, h // 2)
+        M = cv2.getRotationMatrix2D(center, angle, 1.0)
+        rotated = cv2.warpAffine(cv_img, M, (w, h), flags=cv2.INTER_LINEAR, borderMode=cv2.BORDER_REFLECT)
+        image._imageData = cv2_to_pil(rotated)
+
diff --git a/src/Main.py b/src/Main.py
index d79ee9f..d7ecdd7 100644
--- a/src/Main.py
+++ b/src/Main.py
@@ -1,6 +1,13 @@
-#!/usr/bin/python
-from GUI import GUI
-
-if __name__ == "__main__":
-    gui = GUI()
-    gui.initialise()
\ No newline at end of file
+#!/usr/bin/python
+import os
+import sys
+
+CURRENT_DIR = os.path.dirname(__file__)
+if CURRENT_DIR not in sys.path:
+    sys.path.insert(0, CURRENT_DIR)
+
+from GUI import GUI
+
+if __name__ == "__main__":
+    gui = GUI()
+    gui.initialise()
diff --git a/src/utils/image_utils.py b/src/utils/image_utils.py
new file mode 100644
index 0000000..a53f3da
--- /dev/null
+++ b/src/utils/image_utils.py
@@ -0,0 +1,44 @@
+import cv2
+import numpy as np
+from PIL import Image
+
+
+def pil_to_cv2(pil_image: Image.Image) -> np.ndarray:
+    """Convert PIL Image to OpenCV image (always BGR 3-channel when color)."""
+    mode = pil_image.mode
+    arr = np.array(pil_image)
+
+    # Handle grayscale
+    if mode in ("1", "L"):
+        # arr is 2D. Convert to 3-channel BGR for downstream ops expecting color
+        return cv2.cvtColor(arr, cv2.COLOR_GRAY2BGR)
+
+    # Handle images with alpha channel by dropping alpha for processing
+    if mode in ("LA", "RGBA"):
+        # Convert to RGB first
+        pil_rgb = pil_image.convert("RGB")
+        arr = np.array(pil_rgb)
+        return cv2.cvtColor(arr, cv2.COLOR_RGB2BGR)
+
+    # Assume RGB-like
+    if arr.ndim == 3 and arr.shape[2] == 3:
+        return cv2.cvtColor(arr, cv2.COLOR_RGB2BGR)
+
+    # Fallback: if still single-channel, expand to BGR
+    if arr.ndim == 2:
+        return cv2.cvtColor(arr, cv2.COLOR_GRAY2BGR)
+
+    return arr
+
+
+def cv2_to_pil(cv_image: np.ndarray) -> Image.Image:
+    """Convert OpenCV image (BGR or GRAY) to PIL Image (RGB or L)."""
+    if cv_image.ndim == 2:
+        return Image.fromarray(cv_image)
+    rgb = cv2.cvtColor(cv_image, cv2.COLOR_BGR2RGB)
+    return Image.fromarray(rgb)
+
+
+def clamp_int(value: float, min_value: int = 0, max_value: int = 255) -> int:
+    return int(max(min_value, min(max_value, round(value))))
+