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guilan-multimedia-lab/backend/processing/registry.py

434 lines
21 KiB
Python

import math
import cv2
import numpy as np
from .algorithms import (
ProcessingError,
bit_plane,
box_filter,
contrast_stretch,
gamma,
gray_slice,
gray_to_rgb,
histogram_equalization,
logarithmic,
negative,
normalize_to_uint8,
to_gray,
weighted_average,
median_filter,
high_boost,
ensure_uint8,
)
CH_BASIC = "Basic"
CH3 = "Image Enhancement in the Spatial Domain"
CH4 = "Image Enhancement in the Frequency Domain"
CH6 = "Color Image Processing"
def with_meta(schema, *, label=None, description=None, show_when=None):
"""Attach frontend display metadata to a parameter schema."""
if label:
schema["label"] = label
if description:
schema["description"] = description
if show_when:
schema["show_when"] = show_when
return schema
def odd_param(default=3, max_value=35, **meta):
"""Build a schema for odd-valued mask parameters such as K or N."""
return with_meta({"type": "int", "default": default, "min": 3, "max": max_value, "step": 2, "odd": True}, **meta)
def float_param(default, min_value, max_value, step=0.1, **meta):
"""Build a schema for a floating-point slider/input parameter."""
return with_meta({"type": "float", "default": default, "min": min_value, "max": max_value, "step": step}, **meta)
def int_param(default, min_value, max_value, step=1, **meta):
"""Build a schema for an integer slider/input parameter."""
return with_meta({"type": "int", "default": default, "min": min_value, "max": max_value, "step": step}, **meta)
def select_param(default, choices, **meta):
"""Build a schema for a dropdown/select parameter."""
return with_meta({"type": "select", "default": default, "choices": choices}, **meta)
def bool_param(default=False, **meta):
"""Build a schema for a boolean/toggle parameter."""
return with_meta({"type": "bool", "default": default}, **meta)
def kernel_preview(title, matrix, scale=None):
"""Describe a single matrix preview shown beside an operation."""
return {"title": title, "matrix": matrix, "scale": scale}
def kernel_pair_preview(title, gx, gy):
"""Describe related Gx/Gy derivative masks shown as one preview."""
return {"title": title, "kernels": [{"label": "Gx", "matrix": gx}, {"label": "Gy", "matrix": gy}]}
def mask_param(default=3, max_value=35, label="Mask size"):
"""Build the common odd window-size parameter used by order-statistic filters."""
schema = odd_param(default, max_value)
schema["label"] = label
return schema
def histeq(image, params):
"""Apply MATLAB-style histogram equalization to grayscale or RGB channels.
Use it to automatically improve global contrast without manually choosing gray-level limits.
"""
if image.ndim == 2:
return histogram_equalization(image, params)
channels = [histogram_equalization(image[:, :, idx], params)[:, :, 0] for idx in range(3)]
return np.stack(channels, axis=2).astype(np.uint8)
def rgb_to_gray_matlab(image, params):
"""Convert RGB to grayscale using configurable MATLAB-style channel weights.
Use it before intensity-based processing when color is not needed or when matching MATLAB examples.
"""
if image.ndim == 2:
return image
red_weight = float(params.get("red_weight", 0.299))
green_weight = float(params.get("green_weight", 0.587))
blue_weight = float(params.get("blue_weight", 0.114))
total = red_weight + green_weight + blue_weight
if not np.isfinite(total) or math.isclose(total, 0.0):
raise ProcessingError("Grayscale weights must have a non-zero finite sum.")
weights = np.array([red_weight, green_weight, blue_weight], dtype=np.float32) / total
gray = np.tensordot(image.astype(np.float32), weights, axes=([2], [0]))
return ensure_uint8(np.round(gray))
def gaussian_noise(image, params):
"""Add Gaussian noise, g = f + n, where n has configurable mean and variance.
Use it to simulate sensor-like random noise before testing smoothing filters.
"""
mean = float(params.get("mean", 0))
variance = float(params.get("variance", 0.01))
sigma = math.sqrt(max(variance, 0.0)) * 255.0
noise = np.random.default_rng().normal(mean * 255.0, sigma, size=image.shape)
return ensure_uint8(np.round(image.astype(np.float32) + noise))
def salt_pepper_noise(image, params):
"""Add impulse noise by randomly replacing pixels with black or white values.
Use it to test order-statistic denoising, especially the median filter.
"""
amount = float(params.get("amount", 0.03))
salt_ratio = float(params.get("salt_ratio", 0.5))
output = image.copy()
rng = np.random.default_rng()
mask = rng.random(image.shape[:2])
salt = mask < amount * salt_ratio
pepper = (mask >= amount * salt_ratio) & (mask < amount)
output[salt] = 255
output[pepper] = 0
return output
def noise_filter(image, params):
"""Dispatch the selected noise model from the single public Noise Filter operation.
Use it to keep noise experiments in one UI action while changing only the noise type.
"""
kind = params.get("kind", "gaussian")
if kind == "salt_pepper":
return salt_pepper_noise(image, params)
return gaussian_noise(image, params)
def average_noisy_copies(image, params):
"""Generate N Gaussian-noisy copies of one image and average them into one result.
Use it to demonstrate how averaging many independent noisy observations reduces random Gaussian noise.
"""
count = int(params.get("N", 100))
if count < 1 or count > 500:
raise ProcessingError("N must be between 1 and 500.")
kind = params.get("kind", "gaussian")
if kind != "gaussian":
raise ProcessingError("Only gaussian noise is supported for noisy-copy averaging.")
mean = float(params.get("mean", 0))
variance = float(params.get("variance", 0.01))
if not np.isfinite(mean) or not np.isfinite(variance) or variance < 0:
raise ProcessingError("Gaussian mean must be finite and variance must be non-negative.")
rng = np.random.default_rng()
sigma = math.sqrt(variance) * 255.0
source = image.astype(np.float32)
total = np.zeros_like(source, dtype=np.float32)
for _ in range(count):
noise = rng.normal(mean * 255.0, sigma, size=image.shape)
total += np.clip(source + noise, 0, 255)
return ensure_uint8(np.round(total / count))
def gaussian_filter(image, params):
"""Apply a Gaussian low-pass filter controlled by mask size K and variance Q.
Use it to reduce Gaussian noise with a smoother, more natural blur than a box filter.
"""
size = int(params.get("K", params.get("size", 3)))
variance = float(params.get("Q", params.get("variance", 1.0)))
if size < 3 or size % 2 == 0:
raise ProcessingError("K must be an odd integer >= 3.")
sigma = math.sqrt(max(variance, 1e-8))
return cv2.GaussianBlur(image, (size, size), sigmaX=sigma, sigmaY=sigma, borderType=cv2.BORDER_REFLECT)
def max_filter(image, params):
"""Apply a max filter that replaces each pixel with the local neighborhood maximum.
Use it to expand bright regions or reduce isolated dark pepper noise.
"""
size = int(params.get("mask_size", params.get("N", params.get("size", 3))))
if size < 3 or size % 2 == 0:
raise ProcessingError("Mask size must be an odd integer >= 3.")
return cv2.dilate(image, np.ones((size, size), np.uint8))
def min_filter(image, params):
"""Apply a min filter that replaces each pixel with the local neighborhood minimum.
Use it to expand dark regions or reduce isolated bright salt noise.
"""
size = int(params.get("mask_size", params.get("N", params.get("size", 3))))
if size < 3 or size % 2 == 0:
raise ProcessingError("Mask size must be an odd integer >= 3.")
return cv2.erode(image, np.ones((size, size), np.uint8))
def box_denoise(image, params):
"""Apply the average/box filter using a K x K normalized mask.
Use it as the simplest low-pass filter for smoothing and basic noise reduction.
"""
return box_filter(image, {"size": params.get("K", params.get("mask_size", params.get("size", 3)))})
def weighted_denoise(image, params):
"""Apply the fixed 3 x 3 weighted average filter with 1/16 normalization.
Use it when you want mild smoothing that keeps the center pixel more important.
"""
return weighted_average(image, {"size": 3})
def median_denoise(image, params):
"""Apply median filtering with an odd local window, useful for salt-and-pepper noise.
Use it when impulse noise appears as random black and white pixels.
"""
return median_filter(image, {"size": params.get("mask_size", params.get("N", params.get("size", 3)))})
def gaussian_denoise(image, params):
"""Apply Gaussian smoothing using K for mask size and Q for variance.
Use it for denoising random Gaussian noise while avoiding the blocky look of a box filter.
"""
size = params.get("K", params.get("mask_size", params.get("size", 3)))
variance = params.get("Q", params.get("variance", 1.0))
return gaussian_filter(image, {"K": size, "Q": variance})
def high_boost_slide(image, params):
"""Apply high-boost filtering with slide-style parameters A and K.
Use it to make edges and fine structures stronger after smoothing has removed the low-frequency background.
"""
return high_boost(image, {"amplification": params.get("A", params.get("amplification", 1.5)), "size": params.get("K", params.get("size", 3))})
def laplacian_slide(image, params):
"""Sharpen with one of the two taught Laplacian sharpening masks.
Use it to highlight fine detail with the same cross or diagonal masks shown in the slides.
"""
mask_name = params.get("mask", "cross")
kernels = {
"cross": np.array([[0, 1, 0], [1, -5, 1], [0, 1, 0]], dtype=np.float32),
"diagonal": np.array([[1, 1, 1], [1, -9, 1], [1, 1, 1]], dtype=np.float32),
}
kernel = kernels.get(mask_name)
if kernel is None:
raise ProcessingError("Unknown Laplacian mask.")
if image.ndim == 2:
return ensure_uint8(cv2.filter2D(image.astype(np.float32), cv2.CV_32F, kernel, borderType=cv2.BORDER_REFLECT))
channels = [cv2.filter2D(image[:, :, idx], cv2.CV_32F, kernel, borderType=cv2.BORDER_REFLECT) for idx in range(image.shape[2])]
result = np.stack(channels, axis=2)
return ensure_uint8(result)
def gradient_abs_sum(image, params):
"""Compute Sobel or Roberts edges as abs(imfilter(f,Gx)) + abs(imfilter(f,Gy)).
Use it to emphasize prominent edges before combining them with a sharpened image.
"""
operator = params.get("operator", "sobel")
gray = to_gray(image).astype(np.float32)
if operator == "roberts":
gx = np.array([[-1, 0], [0, 1]], dtype=np.float32)
gy = np.array([[0, -1], [1, 0]], dtype=np.float32)
else:
gx = np.array([[-1, -2, -1], [0, 0, 0], [1, 2, 1]], dtype=np.float32)
gy = np.array([[-1, 0, 1], [-2, 0, 2], [-1, 0, 1]], dtype=np.float32)
fx = cv2.filter2D(gray, cv2.CV_32F, gx, borderType=cv2.BORDER_REFLECT)
fy = cv2.filter2D(gray, cv2.CV_32F, gy, borderType=cv2.BORDER_REFLECT)
return gray_to_rgb(normalize_to_uint8(np.abs(fx) + np.abs(fy)))
def rgb_channel(image, params):
"""Extract one RGB channel and show it as a grayscale image.
Use it to inspect how much information each color component contributes.
"""
if image.ndim == 2:
return image
channel = params.get("channel", "r")
index = {"r": 0, "g": 1, "b": 2}.get(channel, 0)
return gray_to_rgb(image[:, :, index])
def fft_spectrum(image, params):
"""Display the DFT magnitude, log magnitude, or phase spectrum of an image.
Use it to understand whether image information is concentrated in low or high frequencies.
"""
gray = to_gray(image).astype(np.float32)
spectrum = np.fft.fftshift(np.fft.fft2(gray))
mode = params.get("mode", "log_magnitude")
if mode == "phase":
return gray_to_rgb(normalize_to_uint8(np.angle(spectrum)))
magnitude = np.abs(spectrum)
if mode == "log_magnitude":
magnitude = np.log1p(magnitude)
return gray_to_rgb(normalize_to_uint8(magnitude))
def operation(id, label, chapter, slide_group, func, params=None, supports="both", matrices=None, formula="", repeatable=True):
"""Create one operation registry entry consumed by the API and frontend."""
return {
"id": id,
"label": label,
"chapter": chapter,
"slide_group": slide_group,
"params": params or {},
"supports": supports,
"matrices": matrices or [],
"formula": formula,
"repeatable": repeatable,
"func": func,
}
OPERATIONS = [
operation("histeq", "Histogram Equalization", CH_BASIC, "Histogram", histeq, formula="Default histeq: map gray levels by the cumulative histogram CDF.", repeatable=False),
operation("negative", "Negative", CH3, "Point Processing", negative, formula="s = 255 - r", repeatable=False),
operation("log", "Log", CH3, "Point Processing", logarithmic, {"c": float_param(1.44, 0.1, 5, 0.05, description="Scale factor in s = c log(1 + r).")}, formula="s = c log(1 + r)", repeatable=False),
operation("gamma", "Power-Law / Gamma", CH3, "Point Processing", gamma, {"gamma": float_param(1.0, 0.1, 5, 0.05, description="Exponent gamma in s = c r^gamma."), "c": float_param(1.0, 0.1, 3, 0.05, description="Scale factor c in s = c r^gamma.")}, formula="s = c r^gamma", repeatable=False),
operation("contrast_stretch", "Gray-Level Dynamic Range", CH3, "Piecewise Linear", contrast_stretch, {"low": int_param(30, 0, 254, description="Input gray level mapped toward 0."), "high": int_param(220, 1, 255, description="Input gray level mapped toward 255.")}, formula="Stretch [low, high] to [0, 255].", repeatable=False),
operation("gray_slice", "Gray-Level Slicing", CH3, "Piecewise Linear", gray_slice, {"start": int_param(96, 0, 255, description="Lower bound A of highlighted range [A, B]."), "end": int_param(160, 0, 255, description="Upper bound B of highlighted range [A, B]."), "preserve_background": bool_param(True, description="Keep original background outside [A, B].")}, formula="Highlight gray range A <= r <= B.", repeatable=False),
operation("bit_plane", "Bit-Plane Slicing", CH3, "Piecewise Linear", bit_plane, {"bit": int_param(7, 0, 7, description="Bit plane index, 0 least significant through 7 most significant.")}, formula="Output bit k of each gray level.", repeatable=False),
operation("noise_filter", "Noise Filter", CH3, "Noise and Denoising", noise_filter, {
"kind": select_param("gaussian", ["gaussian", "salt_pepper"], description="Select the noise model."),
"mean": float_param(0, -1, 1, 0.01, description="Gaussian mean in normalized intensity units.", show_when={"param": "kind", "value": "gaussian"}),
"variance": float_param(0.01, 0, 0.2, 0.005, description="Gaussian variance; sigma = sqrt(variance).", show_when={"param": "kind", "value": "gaussian"}),
"amount": float_param(0.03, 0, 0.5, 0.01, description="Salt-and-pepper probability per pixel.", show_when={"param": "kind", "value": "salt_pepper"}),
"salt_ratio": float_param(0.5, 0, 1, 0.05, description="Fraction of impulse noise assigned to salt.", show_when={"param": "kind", "value": "salt_pepper"}),
}, formula="Gaussian: g=f+n. Salt-pepper: pixels become 0 or 255."),
operation("average_noisy_copies", "Average N Noisy Copies", CH3, "Noise and Denoising", average_noisy_copies, {
"N": int_param(100, 1, 500, description="Number of independent noisy copies to generate and average."),
"kind": select_param("gaussian", ["gaussian"], description="Noise type used for generated copies."),
"mean": float_param(0, -1, 1, 0.01, description="Gaussian mean in normalized intensity units."),
"variance": float_param(0.01, 0, 0.2, 0.005, description="Gaussian variance; lower values add weaker noise."),
}, formula="result = (1/N) sum_i (f + n_i), with gaussian n_i.", repeatable=False),
operation("box_filter", "Average / Box Filter", CH3, "Linear Low-Pass Filters", box_denoise, {"K": odd_param(3, 35, description="Odd mask dimension K for the K x K average mask.")}, matrices=[kernel_preview("1 / K^2 box mask", [["1", "1", "1"], ["1", "1", "1"], ["1", "1", "1"]], "1 / K^2")], formula="g = imfilter(f, ones(K,K)/K^2)"),
operation("weighted_average", "Weighted Average Filter", CH3, "Linear Low-Pass Filters", weighted_denoise, matrices=[kernel_preview("Weighted average mask", [[1, 2, 1], [2, 4, 2], [1, 2, 1]], "1 / 16")], formula="g = imfilter(f, weighted mask)"),
operation("gaussian_filter", "Gaussian Filter", CH3, "Linear Low-Pass Filters", gaussian_denoise, {"K": odd_param(3, 35, description="Odd Gaussian mask dimension K."), "Q": float_param(1.0, 0.01, 25, 0.1, description="Variance Q of the Gaussian mask.")}, formula="Gaussian mask controlled by K and variance Q."),
operation("median_filter", "Median Filter", CH3, "Order-Statistics Filters", median_denoise, {"mask_size": mask_param(3, 25, "Window size")}, formula="g(x,y) = median of neighborhood."),
operation("max_filter", "Max Filter", CH3, "Order-Statistics Filters", max_filter, {"mask_size": mask_param(3, 25, "Window size")}, formula="g(x,y) = max of neighborhood."),
operation("min_filter", "Min Filter", CH3, "Order-Statistics Filters", min_filter, {"mask_size": mask_param(3, 25, "Window size")}, formula="g(x,y) = min of neighborhood."),
operation("laplacian_slide", "Laplacian Sharpening Masks", CH3, "Sharpening Spatial Filters", laplacian_slide, {"mask": select_param("cross", ["cross", "diagonal"], description="Choose one of the taught sharpening masks.")}, matrices=[
kernel_preview("Sharpening cross mask", [[0, 1, 0], [1, -5, 1], [0, 1, 0]]),
kernel_preview("Sharpening diagonal mask", [[1, 1, 1], [1, -9, 1], [1, 1, 1]]),
], formula="Sharpen with selected Laplacian mask."),
operation("gradient_abs_sum", "Gradient Operators", CH3, "Gradient Operator", gradient_abs_sum, {"operator": select_param("sobel", ["sobel", "roberts"], description="Choose Gx/Gy pair.")}, matrices=[
kernel_pair_preview("Roberts Cross-Gradient", [[-1, 0], [0, 1]], [[0, -1], [1, 0]]),
kernel_pair_preview("Sobel", [[-1, -2, -1], [0, 0, 0], [1, 2, 1]], [[-1, 0, 1], [-2, 0, 2], [-1, 0, 1]]),
], formula="Gradient image = abs(imfilter(f,Gx)) + abs(imfilter(f,Gy))."),
operation("high_boost", "High-Boost / Edge Emphasis", CH3, "High-Boost Filtering", high_boost_slide, {"A": float_param(1.5, 1, 6, 0.1, description="Boost factor A, where A >= 1."), "K": odd_param(3, 35, description="Odd averaging mask size used for the blurred image.")}, formula="f_hb = A f - blurred(f)."),
operation("fft_spectrum", "FFT/DFT Spectrum View", CH4, "DFT and FFT", fft_spectrum, {"mode": select_param("log_magnitude", ["magnitude", "log_magnitude", "phase"], description="Choose magnitude, log magnitude, or phase display.")}, formula="F(u,v) = DFT{f(x,y)}", repeatable=False),
operation("rgb_to_gray", "Convert to Grayscale", CH6, "Color Conversion", rgb_to_gray_matlab, {"red_weight": float_param(0.299, 0, 1, 0.001, description="R coefficient in gray = aR + bG + cB."), "green_weight": float_param(0.587, 0, 1, 0.001, description="G coefficient in gray = aR + bG + cB."), "blue_weight": float_param(0.114, 0, 1, 0.001, description="B coefficient in gray = aR + bG + cB.")}, formula="gray = 0.299R + 0.587G + 0.114B by default.", repeatable=False),
operation("rgb_channel", "RGB Channel View", CH6, "RGB color model", rgb_channel, {"channel": select_param("r", ["r", "g", "b"], description="Select the RGB channel to view.")}, formula="Show one RGB channel as grayscale.", repeatable=False),
]
OPERATION_MAP = {item["id"]: item for item in OPERATIONS}
def operation_metadata():
"""Return public operation definitions without executable Python callables."""
return [{key: value for key, value in item.items() if key != "func"} for item in OPERATIONS]
def apply_registered_operation(image, operation_id, params=None):
"""Apply one registered operation, optionally repeating it with the hidden _repeat value.
Use repetition to apply the same filter several times in one saved state.
"""
item = OPERATION_MAP.get(operation_id)
if item is None:
raise ProcessingError(f"Unsupported operation '{operation_id}'.")
operation_params = dict(params or {})
repeat_count = int(operation_params.pop("_repeat", 1))
if repeat_count < 1 or repeat_count > 20:
raise ProcessingError("N must be between 1 and 20.")
result = ensure_uint8(image)
for _ in range(repeat_count):
result = ensure_uint8(item["func"](result, operation_params))
return result