#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
TIF Image Cropping Utility
This script provides functionality for cropping TIF images by automatically
detecting content areas and removing excess whitespace.
"""
import argparse
import os
from typing import Optional, Tuple
import cv2
import numpy as np
def find_content_area(image_path: str) -> Tuple[int, int, int, int]:
"""
Find the bounding box of the content area in an image.
Args:
image_path: Path to the image file
Returns:
Tuple containing (x, y, width, height) of the content area
Raises:
FileNotFoundError: If the image cannot be read
"""
# Read the image
img = cv2.imread(image_path)
if img is None:
raise FileNotFoundError(f"Unable to read image file: {image_path}")
# Convert to grayscale
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
# Apply adaptive thresholding for better detection of content
# This works better for images with varying brightness
thresh = cv2.adaptiveThreshold(
gray, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY_INV, 11, 2
)
# Alternative method: standard thresholding
# _, thresh = cv2.threshold(gray, 250, 255, cv2.THRESH_BINARY_INV)
# Find all non-zero points (colored or non-white pixels)
points = cv2.findNonZero(thresh)
# Get the bounding rectangle around the non-zero points
if points is not None:
x, y, w, h = cv2.boundingRect(points)
return x, y, w, h
else:
# If no points found, return the whole image
h, w = img.shape[:2]
return 0, 0, w, h
def resize_image(
img: np.ndarray,
target_dpi: int = 600,
max_width: int = 2000,
max_height: int = 2000,
verbose: bool = False,
) -> np.ndarray:
"""
Resize an image to meet target DPI and maximum dimensions constraints.
Args:
img: Input image as numpy array
target_dpi: Target DPI (dots per inch) for the image
max_width: Maximum width in pixels
max_height: Maximum height in pixels
verbose: Whether to print detailed information
Returns:
Resized image as numpy array
"""
height, width = img.shape[:2]
# Calculate if resizing is needed
if width > max_width or height > max_height:
# Determine the scaling factor to fit within max dimensions
scale_factor = min(max_width / width, max_height / height)
# Calculate new dimensions
new_width = int(width * scale_factor)
new_height = int(height * scale_factor)
if verbose:
print(f"Resizing image from {width}x{height} to {new_width}x{new_height}")
print(f"Scale factor: {scale_factor:.2f}")
# Resize the image
resized_img = cv2.resize(
img, (new_width, new_height), interpolation=cv2.INTER_AREA
)
return resized_img
else:
if verbose:
print(
f"No resizing needed, image dimensions {width}x{height} are within limits"
)
return img
def crop_tif(
input_path: str,
output_path: Optional[str] = None,
margin: int = 30,
resize: bool = True,
target_dpi: int = 600,
max_width: int = 2000,
max_height: int = 2000,
overwrite: bool = False,
verbose: bool = False,
) -> None:
"""
Crop a TIF image to its content area with a specified margin and optionally resize it.
Args:
input_path: Path to the input TIF image
output_path: Path to save the cropped image (defaults to input_path if overwrite=True)
margin: Margin in pixels to add around the content area
resize: Whether to resize the image to meet target constraints
target_dpi: Target DPI for the resized image
max_width: Maximum width in pixels for the resized image
max_height: Maximum height in pixels for the resized image
overwrite: Whether to overwrite the input file
verbose: Whether to print detailed information
Raises:
FileNotFoundError: If the input image cannot be read
ValueError: If output path is not specified and overwrite is False
"""
# Determine output path
if output_path is None:
if overwrite:
output_path = input_path
else:
raise ValueError("output_path must be specified if overwrite=False")
# Read the image
img = cv2.imread(input_path)
if img is None:
raise FileNotFoundError(f"Unable to read image file: {input_path}")
original_height, original_width = img.shape[:2]
if verbose:
print(f"Original image dimensions: {original_width}x{original_height}")
# Find the content area
x, y, w, h = find_content_area(input_path)
if verbose:
print(f"Content area detected at: x={x}, y={y}, width={w}, height={h}")
# Calculate the coordinates with margin, clamping to the image boundaries
x_start = max(x - margin, 0)
y_start = max(y - margin, 0)
x_end = min(x + w + margin, img.shape[1])
y_end = min(y + h + margin, img.shape[0])
if verbose:
print(f"Cropping to: x={x_start}:{x_end}, y={y_start}:{y_end}")
print(f"New dimensions: {x_end - x_start}x{y_end - y_start}")
# Crop the image using the bounding rectangle with margin
cropped_img = img[y_start:y_end, x_start:x_end]
# Resize the image if requested
if resize:
cropped_img = resize_image(
cropped_img, target_dpi, max_width, max_height, verbose
)
# Save the processed image
cv2.imwrite(output_path, cropped_img)
# Calculate space saved
final_height, final_width = cropped_img.shape[:2]
area_reduction = 1 - (
(final_width * final_height) / (original_width * original_height)
)
area_reduction_pct = area_reduction * 100
print(f"Image processed: {input_path}")
print(
f"Size changed from {original_width}x{original_height} to {final_width}x{final_height}"
)
print(f"Saved {area_reduction_pct:.1f}% of the original area")
if output_path != input_path:
print(f"Saved to: {output_path}")
def batch_crop_tifs(
directory: str,
output_directory: Optional[str] = None,
margin: int = 30,
resize: bool = True,
target_dpi: int = 600,
max_width: int = 2000,
max_height: int = 2000,
recursive: bool = False,
verbose: bool = False,
) -> None:
"""
Process all TIF files in a directory.
Args:
directory: Directory containing TIF files to process
output_directory: Directory to save processed files (defaults to same as input)
margin: Margin to add around the content area
resize: Whether to resize images to meet target constraints
target_dpi: Target DPI for resized images
max_width: Maximum width in pixels for resized images
max_height: Maximum height in pixels for resized images
recursive: Whether to process subdirectories
verbose: Whether to print detailed information
"""
if not os.path.isdir(directory):
raise ValueError(f"Directory not found: {directory}")
# Create output directory if it doesn't exist
if output_directory and not os.path.exists(output_directory):
os.makedirs(output_directory)
# Get the list of TIF files
files = []
if recursive:
for root, _, filenames in os.walk(directory):
for filename in filenames:
if filename.lower().endswith((".tif", ".tiff")):
files.append(os.path.join(root, filename))
else:
files = [
os.path.join(directory, f)
for f in os.listdir(directory)
if f.lower().endswith((".tif", ".tiff"))
]
print(f"Found {len(files)} TIF files to process")
# Process each file
for index, file_path in enumerate(files):
if verbose:
print(f"\nProcessing [{index + 1}/{len(files)}]: {file_path}")
else:
print(
f"Processing [{index + 1}/{len(files)}]: {os.path.basename(file_path)}"
)
# Determine output path
if output_directory:
rel_path = os.path.relpath(file_path, directory)
output_path = os.path.join(output_directory, rel_path)
# Create subdirectories if needed
output_subdir = os.path.dirname(output_path)
if not os.path.exists(output_subdir):
os.makedirs(output_subdir)
else:
output_path = file_path
# Process the image
try:
crop_tif(
file_path,
output_path,
margin,
resize,
target_dpi,
max_width,
max_height,
output_path == file_path,
verbose,
)
except Exception as e:
print(f"Error processing {file_path}: {e}")
def main():
"""Main function to parse arguments and execute the appropriate action."""
# Set up argument parser
parser = argparse.ArgumentParser(
description="Process TIF images: crop to content area, resize, and optimize for publications.",
formatter_class=argparse.ArgumentDefaultsHelpFormatter,
)
# Add subparsers for the different modes
subparsers = parser.add_subparsers(dest="mode", help="Operation mode")
# Single file mode
file_parser = subparsers.add_parser("file", help="Process a single file")
file_parser.add_argument("-i", "--input", required=True, help="Input TIF file path")
file_parser.add_argument(
"-o", "--output", help="Output TIF file path (defaults to input if --overwrite)"
)
file_parser.add_argument(
"--overwrite", action="store_true", help="Overwrite the input file"
)
# Batch mode
batch_parser = subparsers.add_parser("batch", help="Process multiple files")
batch_parser.add_argument(
"-d", "--directory", required=True, help="Directory containing TIF files"
)
batch_parser.add_argument(
"-o", "--output-directory", help="Output directory for processed files"
)
batch_parser.add_argument(
"-r",
"--recursive",
action="store_true",
help="Process subdirectories recursively",
)
# Common arguments
for subparser in [file_parser, batch_parser]:
subparser.add_argument(
"--margin", type=int, default=30, help="Margin size around the content area"
)
subparser.add_argument(
"--no-resize", action="store_true", help="Disable automatic resizing"
)
subparser.add_argument(
"--dpi", type=int, default=600, help="Target DPI for resized images"
)
subparser.add_argument(
"--max-width", type=int, default=2000, help="Maximum width in pixels"
)
subparser.add_argument(
"--max-height", type=int, default=2000, help="Maximum height in pixels"
)
subparser.add_argument(
"-v", "--verbose", action="store_true", help="Enable verbose output"
)
# Parse arguments
args = parser.parse_args()
# Execute the appropriate action
if args.mode == "file":
crop_tif(
args.input,
args.output,
args.margin,
not args.no_resize, # Invert --no-resize flag to get resize boolean
args.dpi,
args.max_width,
args.max_height,
args.overwrite,
args.verbose,
)
elif args.mode == "batch":
batch_crop_tifs(
args.directory,
args.output_directory,
args.margin,
not args.no_resize, # Invert --no-resize flag to get resize boolean
args.dpi,
args.max_width,
args.max_height,
args.recursive,
args.verbose,
)
else:
parser.print_help()
if __name__ == "__main__":
main()
/