SynthField / experiments /image2image /image_similarity.py
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import torch
import torch.nn.functional as F
from torchvision import models, transforms
from PIL import Image
import numpy as np
import os
from pathlib import Path
import matplotlib.pyplot as plt
import seaborn as sns
from scipy.spatial.distance import sqeuclidean
from scipy import linalg
class ImageSimilarityFinder:
def __init__(self, model_name='resnet50', device=None):
"""
Initialize the image similarity finder with a vision encoder model.
Args:
model_name: Name of the pretrained model ('resnet50', 'vit_b_32', etc.)
device: torch device (cuda or cpu)
"""
self.device = device if device else torch.device('cuda' if torch.cuda.is_available() else 'cpu')
print(f"Using device: {self.device}")
# Load pretrained model
if model_name == 'resnet50':
self.model = models.resnet50(pretrained=True)
# Remove the final classification layer to get embeddings
self.model = torch.nn.Sequential(*list(self.model.children())[:-1])
elif model_name == 'efficientnet':
self.model = models.efficientnet_b0(pretrained=True)
self.model = torch.nn.Sequential(*list(self.model.children())[:-1])
else:
raise ValueError(f"Model {model_name} not supported")
self.model = self.model.to(self.device)
self.model.eval()
# Image preprocessing
self.transform = transforms.Compose([
transforms.Resize((224, 224)),
transforms.ToTensor(),
transforms.Normalize(
mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225]
)
])
def get_image_embedding(self, image_path):
"""Extract embedding from an image."""
image = Image.open(image_path).convert('RGB')
image_tensor = self.transform(image).unsqueeze(0).to(self.device)
with torch.no_grad():
embedding = self.model(image_tensor)
# Flatten the embedding
embedding = embedding.view(embedding.size(0), -1)
return embedding
def compute_similarity(self, embedding1, embedding2, metric='cosine'):
"""
Compute similarity between two embeddings.
Args:
embedding1, embedding2: Image embeddings
metric: 'cosine' or 'euclidean'
Returns:
Similarity score (0-1 for cosine)
"""
if metric == 'cosine':
similarity = F.cosine_similarity(embedding1, embedding2, dim=1)
elif metric == 'euclidean':
distance = torch.norm(embedding1 - embedding2, dim=1)
similarity = 1 / (1 + distance) # Convert distance to similarity
else:
raise ValueError(f"Metric {metric} not supported")
return similarity.item()
def find_similar_images(self, folder_path, metric='cosine', target_image_file=None):
"""
Find similarities between images in a folder.
If target_image_file is specified, computes similarity of all other images to that one.
Otherwise, computes an all-vs-all similarity matrix.
Args:
folder_path: Path to folder containing images
metric: 'cosine' or 'euclidean'
target_image_file: Filename of the image to compare against others.
Returns:
If target_image_file is given: (other_image_files, similarity_scores_1d)
If target_image_file is None: (all_image_files, similarity_matrix_2d)
"""
# Get all image files
image_extensions = {'.jpg', '.jpeg', '.png', '.bmp', '.gif'}
image_files = [
f for f in os.listdir(folder_path)
if os.path.splitext(f)[1].lower() in image_extensions
]
if not image_files:
print("No images found in the folder!")
return None
print(f"Found {len(image_files)} images: {image_files}")
# Get embeddings for all images
embeddings = {}
print("\nExtracting embeddings...")
for img_file in image_files:
img_path = os.path.join(folder_path, img_file)
embedding = self.get_image_embedding(img_path)
embeddings[img_file] = embedding
print(f" ✓ {img_file}")
if target_image_file:
if target_image_file not in embeddings:
print(f"Error: Target image '{target_image_file}' not found in folder.")
return None
print(f"\nComputing similarity of '{target_image_file}' against other images...")
target_embedding = embeddings[target_image_file]
other_files = [f for f in image_files if f != target_image_file]
scores = []
for other_file in other_files:
score = self.compute_similarity(target_embedding, embeddings[other_file], metric=metric)
scores.append(score)
return other_files, np.array(scores)
else:
# Compute similarity matrix
n_images = len(image_files)
similarity_matrix = np.zeros((n_images, n_images))
print("\nComputing similarities...")
for i, img1 in enumerate(image_files):
for j, img2 in enumerate(image_files):
similarity = self.compute_similarity(
embeddings[img1],
embeddings[img2],
metric=metric
)
similarity_matrix[i, j] = similarity
return image_files, similarity_matrix
def plot_similarity_matrix(self, image_files, similarity_matrix, save_path=None, folder_path=None, target_image_file=None):
"""Visualize the similarity matrix as a heatmap, or as a bar chart if a target image is provided."""
if target_image_file and folder_path and similarity_matrix.ndim == 1:
# One-vs-all bar chart
from matplotlib.offsetbox import OffsetImage, AnnotationBbox
plt.figure(figsize=(15, 9))
ax = plt.gca()
# Sort for better visualization
sorted_indices = np.argsort(similarity_matrix)[::-1]
sorted_files = [image_files[i] for i in sorted_indices]
sorted_scores = similarity_matrix[sorted_indices]
ax.bar(range(len(sorted_files)), sorted_scores, color='lightblue')
ax.set_xticks(range(len(sorted_files)))
ax.set_xticklabels([]) # Hide text labels, we will use images
for i, filename in enumerate(sorted_files):
try:
img_path = os.path.join(folder_path, filename)
img = Image.open(img_path).convert("RGB")
img.thumbnail((120, 120)) # Resize for label
oi = OffsetImage(img, zoom=0.7)
box = AnnotationBbox(oi, (i, 0), frameon=False, xybox=(0, -50), boxcoords="data", pad=0, xycoords="data", box_alignment=(0.5, 1.0))
ax.add_artist(box)
# Add score text above bar
ax.text(i, sorted_scores[i] + 0.01, f'{sorted_scores[i]:.3f}', ha='center', va='bottom', fontsize=9)
except FileNotFoundError:
print(f"Warning: could not find image {filename} to create label.")
ax.text(i, -0.1, filename, rotation=90, ha='center', va='top')
ax.set_ylim(0, 1.1)
ax.set_xlim(-0.7, len(image_files) - 0.3)
ax.set_ylabel('Cosine Similarity (higher = more similar)')
ax.set_title(f'Similarity of other images compared to "{target_image_file}"')
plt.tight_layout(rect=[0, 0.1, 1, 0.95]) # Adjust layout to make space for images
else:
# Original heatmap for matrix
plt.figure(figsize=(10, 8))
sns.heatmap(
similarity_matrix,
xticklabels=image_files,
yticklabels=image_files,
annot=True,
fmt='.3f',
cmap='coolwarm',
vmin=0,
vmax=1
)
plt.title('Image Similarity Matrix (Cosine Similarity)')
plt.tight_layout()
if save_path:
# Create directory if it doesn't exist
os.makedirs(os.path.dirname(save_path), exist_ok=True)
plt.savefig(save_path, dpi=150, bbox_inches='tight')
print(f"\nPlot saved to {save_path}")
plt.show()
def print_similarity_results(self, image_files, similarity_matrix, target_image_file=None):
"""Print similarity results in a readable format."""
print("\n" + "="*80)
print("IMAGE SIMILARITY RESULTS")
print("="*80 + "\n")
if target_image_file and similarity_matrix.ndim == 1:
print(f"Similarities compared to '{target_image_file}':\n")
# Sort for printing
sorted_pairs = sorted(zip(similarity_matrix, image_files), reverse=True)
for similarity, img_file in sorted_pairs:
bar_length = int(similarity * 40)
bar = '█' * bar_length + '░' * (40 - bar_length)
print(f"{img_file}")
print(f" [{bar}] {similarity:.4f}")
else:
for i in range(len(image_files)):
for j in range(i + 1, len(image_files)):
img1 = image_files[i]
img2 = image_files[j]
similarity = similarity_matrix[i, j]
# Create a visual representation
bar_length = int(similarity * 40)
bar = '█' * bar_length + '░' * (40 - bar_length)
print(f"{img1} <-> {img2}")
print(f" [{bar}] {similarity:.4f}")
class FIDSimilarityFinder:
"""Compute Fréchet Inception Distance (FID) between images."""
def __init__(self, device=None):
"""
Initialize FID calculator using InceptionV3 model.
Args:
device: torch device (cuda or cpu)
"""
self.device = device if device else torch.device('cuda' if torch.cuda.is_available() else 'cpu')
print(f"Using device: {self.device}")
# Load InceptionV3 model (pretrained on ImageNet)
inception = models.inception_v3(pretrained=True)
inception.eval()
# Create a wrapper to extract features before the final layer
class InceptionFeatureExtractor(torch.nn.Module):
def __init__(self, inception_model):
super().__init__()
self.inception = inception_model
# Remove the final fc layer
self.inception.fc = torch.nn.Identity()
def forward(self, x):
# Pass through all layers except fc
x = self.inception.Conv2d_1a_3x3(x)
x = self.inception.Conv2d_2a_3x3(x)
x = self.inception.Conv2d_2b_3x3(x)
x = self.inception.maxpool1(x)
x = self.inception.Conv2d_3b_1x1(x)
x = self.inception.Conv2d_4a_3x3(x)
x = self.inception.maxpool2(x)
x = self.inception.Mixed_5b(x)
x = self.inception.Mixed_5c(x)
x = self.inception.Mixed_5d(x)
x = self.inception.Mixed_6a(x)
x = self.inception.Mixed_6b(x)
x = self.inception.Mixed_6c(x)
x = self.inception.Mixed_6d(x)
x = self.inception.Mixed_6e(x)
x = self.inception.Mixed_7a(x)
x = self.inception.Mixed_7b(x)
x = self.inception.Mixed_7c(x)
x = self.inception.avgpool(x)
x = torch.flatten(x, 1)
return x
self.model = InceptionFeatureExtractor(inception)
self.model = self.model.to(self.device)
self.model.eval()
# Image preprocessing for InceptionV3
self.transform = transforms.Compose([
transforms.Resize((299, 299)),
transforms.ToTensor(),
transforms.Normalize(
mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225]
)
])
def get_inception_features(self, image_path):
"""Extract InceptionV3 features from an image."""
image = Image.open(image_path).convert('RGB')
image_tensor = self.transform(image).unsqueeze(0).to(self.device)
with torch.no_grad():
# Pass through the model up to the average pool
features = self.model(image_tensor)
# Flatten to 1D vector for each image
features = features.view(features.size(0), -1)
return features.cpu().numpy()
def calculate_frechet_distance(self, mu1, sigma1, mu2, sigma2, eps=1e-6):
"""Calculate Fréchet distance between two Gaussians."""
mu1 = np.atleast_1d(mu1)
mu2 = np.atleast_1d(mu2)
sigma1 = np.atleast_2d(sigma1)
sigma2 = np.atleast_2d(sigma2)
assert mu1.shape == mu2.shape, "Statistics must have matching dimensions"
assert sigma1.shape == sigma2.shape, "Statistics must have matching dimensions"
# Compute difference
diff = mu1 - mu2
# Compute matrix square root
covmean, _ = linalg.sqrtm(sigma1.dot(sigma2), disp=False)
# Handle complex results
if np.iscomplexobj(covmean):
covmean = covmean.real
# Calculate FID
tr_covmean = np.trace(covmean)
fid = diff.dot(diff) + np.trace(sigma1) + np.trace(sigma2) - 2 * tr_covmean
return np.sqrt(np.maximum(fid, 0.0))
def compute_fid_matrix(self, folder_path, target_image_file=None):
"""
Compute FID between all pairs of images in a folder, or against a single target image.
Lower FID indicates higher similarity.
Args:
folder_path: Path to folder containing images
target_image_file: If specified, compute FID of other images against this one.
Returns:
image_files, fid_scores (1D or 2D array)
"""
# Get all image files
image_extensions = {'.jpg', '.jpeg', '.png', '.bmp', '.gif'}
image_files = sorted([
f for f in os.listdir(folder_path)
if os.path.splitext(f)[1].lower() in image_extensions
])
if not image_files:
print("No images found in the folder!")
return None
print(f"Found {len(image_files)} images: {image_files}")
# Extract features for all images
all_features = {}
print("\nExtracting InceptionV3 features...")
for img_file in image_files:
img_path = os.path.join(folder_path, img_file)
features = self.get_inception_features(img_path)
all_features[img_file] = features
print(f" ✓ {img_file}")
if target_image_file:
if target_image_file not in all_features:
print(f"Error: Target image '{target_image_file}' not found.")
return None
print(f"\nComputing FID of '{target_image_file}' against other images...")
target_mu = all_features[target_image_file].flatten()
other_files = [f for f in image_files if f != target_image_file]
fid_scores = []
for other_file in other_files:
other_mu = all_features[other_file].flatten()
fid = np.linalg.norm(other_mu - target_mu)
fid_scores.append(fid)
return other_files, np.array(fid_scores)
else:
# Compute FID matrix
n_images = len(image_files)
fid_matrix = np.zeros((n_images, n_images))
print("\nComputing FID-based distances...")
for i in range(n_images):
for j in range(i, n_images):
if i == j:
fid_matrix[i, j] = 0.0
else:
mu1 = all_features[image_files[i]].flatten()
mu2 = all_features[image_files[j]].flatten()
# Compute Euclidean distance as FID approximation
fid = np.linalg.norm(mu1 - mu2)
fid_matrix[i, j] = fid
fid_matrix[j, i] = fid
return image_files, fid_matrix
def plot_fid_matrix(self, image_files, fid_matrix, save_path=None, folder_path=None, target_image_file=None):
"""Visualize the FID matrix as a heatmap, or as a bar chart if a target image is provided."""
if target_image_file and folder_path and fid_matrix.ndim == 1:
# One-vs-all bar chart for FID
from matplotlib.offsetbox import OffsetImage, AnnotationBbox
plt.figure(figsize=(15, 9))
ax = plt.gca()
# Sort by distance (ascending)
sorted_indices = np.argsort(fid_matrix)
sorted_files = [image_files[i] for i in sorted_indices]
sorted_scores = fid_matrix[sorted_indices]
ax.bar(range(len(sorted_files)), sorted_scores, color='lightgreen')
ax.set_xticks(range(len(sorted_files)))
ax.set_xticklabels([])
for i, filename in enumerate(sorted_files):
try:
img_path = os.path.join(folder_path, filename)
img = Image.open(img_path).convert("RGB")
img.thumbnail((120, 120))
oi = OffsetImage(img, zoom=0.7)
box = AnnotationBbox(oi, (i, 0), frameon=False, xybox=(0, -50), boxcoords="data", pad=0, xycoords="data", box_alignment=(0.5, 1.0))
ax.add_artist(box)
ax.text(i, sorted_scores[i], f'{sorted_scores[i]:.2f}', ha='center', va='bottom', fontsize=9, bbox=dict(facecolor='white', alpha=0.5, pad=1))
except FileNotFoundError:
print(f"Warning: could not find image {filename} to create label.")
ax.text(i, -0.1, filename, rotation=90, ha='center', va='top')
if len(sorted_scores) > 0:
ax.set_ylim(0, max(sorted_scores) * 1.15)
ax.set_xlim(-0.7, len(image_files) - 0.3)
ax.set_ylabel('FID Distance (lower = more similar)')
ax.set_title(f'FID Distance of other images from "{target_image_file}"')
plt.tight_layout(rect=[0, 0.1, 1, 0.95])
else:
# Original heatmap
plt.figure(figsize=(10, 8))
sns.heatmap(
fid_matrix,
xticklabels=image_files,
yticklabels=image_files,
annot=True,
fmt='.2f',
cmap='RdYlGn_r', # Reversed: red = high distance (different), green = low distance (similar)
cbar_kws={'label': 'FID Distance (lower = more similar)'}
)
plt.title('Fréchet Inception Distance (FID) Matrix')
plt.tight_layout()
if save_path:
# Create directory if it doesn't exist
os.makedirs(os.path.dirname(save_path), exist_ok=True)
plt.savefig(save_path, dpi=150, bbox_inches='tight')
print(f"\nHeatmap saved to {save_path}")
plt.show()
def print_fid_results(self, image_files, fid_matrix, target_image_file=None):
"""Print FID results in a readable format."""
print("\n" + "="*80)
print("FRÉCHET INCEPTION DISTANCE (FID) RESULTS")
print("="*80)
print("\nNote: Lower FID = more similar images\n")
if target_image_file and fid_matrix.ndim == 1:
print(f"FID distances from '{target_image_file}':\n")
# Sort for printing
sorted_pairs = sorted(zip(fid_matrix, image_files))
if not sorted_pairs: return
max_fid = sorted_pairs[-1][0] if sorted_pairs else 1
for fid, img_file in sorted_pairs:
# Inverted bar: shorter is better
bar_length = int((1 - fid / max_fid) * 40) if max_fid > 0 else 0
bar = '█' * bar_length + '░' * (40 - bar_length)
print(f"{img_file}")
print(f" [{bar}] FID: {fid:.4f}")
else:
# Create sorted list of pairwise distances
distances = []
for i in range(len(image_files)):
for j in range(i + 1, len(image_files)):
distances.append((
image_files[i],
image_files[j],
fid_matrix[i, j]
))
# Sort by FID distance
distances.sort(key=lambda x: x[2])
if not distances: return
print("Pairwise FID Distances (sorted by similarity):")
max_fid = max(d[2] for d in distances) if distances else 1
for img1, img2, fid in distances:
# Create a visual representation (inverted: shorter bar = more similar)
bar_length = int((1 - fid / max_fid) * 40) if max_fid > 0 else 0
bar = '█' * bar_length + '░' * (40 - bar_length)
print(f"{img1} <-> {img2}")
print(f" [{bar}] FID: {fid:.4f}")
def main():
# Set folder path and target image
folder_path = "./input"
target_image_file = "rosario.jpg" # The image to compare against others
# Check if target file exists
if not os.path.exists(os.path.join(folder_path, target_image_file)):
print(f"Error: Target image '{target_image_file}' not found in '{folder_path}'")
# List other available images
try:
image_extensions = {'.jpg', '.jpeg', '.png', '.bmp', '.gif'}
avail_images = [f for f in os.listdir(folder_path) if os.path.splitext(f)[1].lower() in image_extensions]
if avail_images:
print("Available images:", avail_images)
except FileNotFoundError:
print(f"Error: Folder '{folder_path}' not found.")
return
print("\n" + "="*80)
print("IMAGE SIMILARITY ANALYSIS")
print(f"Target Image: {target_image_file}")
print("="*80)
# Always perform both analyses for the target image
# Method 1: ResNet50 + Cosine Similarity
print("\n" + "="*80)
print("METHOD 1: ResNet50 + Cosine Similarity")
print("="*80)
similarity_finder = ImageSimilarityFinder(model_name='resnet50')
results = similarity_finder.find_similar_images(
folder_path,
metric='cosine',
target_image_file=target_image_file
)
if results:
image_files, similarity_scores = results
similarity_finder.print_similarity_results(image_files, similarity_scores, target_image_file=target_image_file)
output_path = os.path.join(folder_path,'output', f'similarity_to_{Path(target_image_file).stem}_resnet50.png')
similarity_finder.plot_similarity_matrix(image_files, similarity_scores, output_path, folder_path=folder_path, target_image_file=target_image_file)
# Method 2: InceptionV3 + FID
print("\n" + "="*80)
print("METHOD 2: InceptionV3 + Fréchet Inception Distance (FID)")
print("="*80)
fid_finder = FIDSimilarityFinder()
results = fid_finder.compute_fid_matrix(folder_path, target_image_file=target_image_file)
if results:
image_files, fid_scores = results
fid_finder.print_fid_results(image_files, fid_scores, target_image_file=target_image_file)
output_path = os.path.join(folder_path,'output', f'similarity_to_{Path(target_image_file).stem}_fid.png')
fid_finder.plot_fid_matrix(image_files, fid_scores, output_path, folder_path=folder_path, target_image_file=target_image_file)
print("\n" + "="*80)
print("✓ Analysis complete!")
print("="*80)
if __name__ == "__main__":
main()