| 1 | #!/usr/bin/env python3 |
| 2 | """ |
| 3 | SVG Image Aspect Ratio Fix Tool |
| 4 | |
| 5 | Fixes the dimensions of <image> elements in SVG to match the original image aspect ratio. |
| 6 | This prevents images from being stretched by PowerPoint SVG rendering paths that do not |
| 7 | honor preserveAspectRatio consistently. |
| 8 | |
| 9 | Principle: |
| 10 | Some PowerPoint SVG rendering paths ignore the preserveAspectRatio attribute and directly |
| 11 | stretch the image to fill the area specified by width/height. |
| 12 | |
| 13 | This tool reads the actual image aspect ratio and recalculates the x, y, width, height of |
| 14 | <image> elements so that images are centered and maintain their original aspect ratio. |
| 15 | |
| 16 | Usage: |
| 17 | python3 scripts/svg_finalize/fix_image_aspect.py <svg_file> [svg_file2] ... |
| 18 | python3 scripts/svg_finalize/fix_image_aspect.py projects/xxx/svg_output/*.svg |
| 19 | |
| 20 | # Preview mode |
| 21 | python3 scripts/svg_finalize/fix_image_aspect.py --dry-run projects/xxx/svg_output/*.svg |
| 22 | |
| 23 | Examples: |
| 24 | python3 scripts/svg_finalize/fix_image_aspect.py projects/demo/svg_output/slide_06_current_overview.svg |
| 25 | """ |
| 26 | |
| 27 | import os |
| 28 | import re |
| 29 | import sys |
| 30 | import base64 |
| 31 | import argparse |
| 32 | from pathlib import Path |
| 33 | from xml.etree import ElementTree as ET |
| 34 | |
| 35 | _SCRIPTS_DIR = Path(__file__).resolve().parents[1] |
| 36 | if str(_SCRIPTS_DIR) not in sys.path: |
| 37 | sys.path.insert(0, str(_SCRIPTS_DIR)) |
| 38 | |
| 39 | from console_encoding import configure_utf8_stdio # noqa: E402 |
| 40 | |
| 41 | configure_utf8_stdio() |
| 42 | |
| 43 | # Try to import PIL for getting image dimensions |
| 44 | try: |
| 45 | from PIL import Image |
| 46 | HAS_PIL = True |
| 47 | except ImportError: |
| 48 | HAS_PIL = False |
| 49 | print("[WARN] PIL not installed. Install with: pip install Pillow") |
| 50 | print(" Will try to use basic method for JPEG/PNG files.") |
| 51 | |
| 52 | |
| 53 | def get_image_dimensions_pil(image_path: str) -> tuple[int | None, int | None]: |
| 54 | """Get image dimensions using PIL.""" |
| 55 | try: |
| 56 | with Image.open(image_path) as img: |
| 57 | return img.width, img.height |
| 58 | except Exception as e: |
| 59 | print(f" [WARN] Cannot read image with PIL: {e}") |
| 60 | return None, None |
| 61 | |
| 62 | |
| 63 | def get_image_dimensions_basic(image_path: str) -> tuple[int | None, int | None]: |
| 64 | """Get image dimensions using basic parsing without PIL.""" |
| 65 | try: |
| 66 | with open(image_path, 'rb') as f: |
| 67 | data = f.read(64) # Read header information |
| 68 | |
| 69 | # PNG |
| 70 | if data[:8] == b'\x89PNG\r\n\x1a\n': |
| 71 | w = int.from_bytes(data[16:20], 'big') |
| 72 | h = int.from_bytes(data[20:24], 'big') |
| 73 | return w, h |
| 74 | |
| 75 | # JPEG |
| 76 | if data[:2] == b'\xff\xd8': |
| 77 | # Need to read full file to parse JPEG |
| 78 | with open(image_path, 'rb') as f: |
| 79 | f.seek(2) |
| 80 | while True: |
| 81 | marker = f.read(2) |
| 82 | if not marker or len(marker) < 2: |
| 83 | break |
| 84 | if marker[0] != 0xff: |
| 85 | break |
| 86 | m = marker[1] |
| 87 | # SOF0, SOF2 markers contain dimensions |
| 88 | if m in (0xC0, 0xC2): |
| 89 | f.read(3) # Skip length and precision |
| 90 | h = int.from_bytes(f.read(2), 'big') |
| 91 | w = int.from_bytes(f.read(2), 'big') |
| 92 | return w, h |
| 93 | elif m == 0xD9: # EOI |
| 94 | break |
| 95 | elif m == 0xD8: # SOI |
| 96 | continue |
| 97 | elif 0xD0 <= m <= 0xD7: # RST |
| 98 | continue |
| 99 | else: |
| 100 | length = int.from_bytes(f.read(2), 'big') |
| 101 | f.seek(length - 2, 1) |
| 102 | |
| 103 | return None, None |
| 104 | except Exception as e: |
| 105 | print(f" [WARN] Cannot read image dimensions: {e}") |
| 106 | return None, None |
| 107 | |
| 108 | |
| 109 | def get_image_dimensions_from_base64(data_uri: str) -> tuple[int | None, int | None]: |
| 110 | """Get image dimensions from a Base64 data URI.""" |
| 111 | import io |
| 112 | try: |
| 113 | # Parse data URI |
| 114 | match = re.match(r'data:image/(\w+);base64,(.+)', data_uri) |
| 115 | if not match: |
| 116 | return None, None |
| 117 | |
| 118 | img_format = match.group(1) |
| 119 | b64_data = match.group(2) |
| 120 | img_bytes = base64.b64decode(b64_data) |
| 121 | |
| 122 | if HAS_PIL: |
| 123 | with Image.open(io.BytesIO(img_bytes)) as img: |
| 124 | return img.width, img.height |
| 125 | else: |
| 126 | # Use basic method |
| 127 | if img_bytes[:8] == b'\x89PNG\r\n\x1a\n': |
| 128 | w = int.from_bytes(img_bytes[16:20], 'big') |
| 129 | h = int.from_bytes(img_bytes[20:24], 'big') |
| 130 | return w, h |
| 131 | |
| 132 | return None, None |
| 133 | except Exception as e: |
| 134 | print(f" [WARN] Cannot parse base64 image: {e}") |
| 135 | return None, None |
| 136 | |
| 137 | |
| 138 | def get_image_dimensions(href: str, svg_dir: str) -> tuple[int | None, int | None]: |
| 139 | """Get image dimensions for either inline or external images.""" |
| 140 | # Handle data URI |
| 141 | if href.startswith('data:'): |
| 142 | return get_image_dimensions_from_base64(href) |
| 143 | |
| 144 | # Handle external files |
| 145 | if not os.path.isabs(href): |
| 146 | full_path = os.path.join(svg_dir, href) |
| 147 | else: |
| 148 | full_path = href |
| 149 | |
| 150 | if not os.path.exists(full_path): |
| 151 | print(f" [WARN] Image not found: {href}") |
| 152 | return None, None |
| 153 | |
| 154 | if HAS_PIL: |
| 155 | return get_image_dimensions_pil(full_path) |
| 156 | else: |
| 157 | return get_image_dimensions_basic(full_path) |
| 158 | |
| 159 | |
| 160 | def calculate_fitted_dimensions( |
| 161 | img_width: int, |
| 162 | img_height: int, |
| 163 | box_width: float, |
| 164 | box_height: float, |
| 165 | mode: str = 'meet', |
| 166 | ) -> tuple[float, float, float, float]: |
| 167 | """ |
| 168 | Calculate the fitted dimensions for an image within a bounding box. |
| 169 | |
| 170 | Args: |
| 171 | img_width, img_height: Original image dimensions |
| 172 | box_width, box_height: Container box dimensions |
| 173 | mode: 'meet' preserves aspect ratio and fully displays image (may have whitespace) |
| 174 | 'slice' preserves aspect ratio and fully fills container (may crop) |
| 175 | |
| 176 | Returns: |
| 177 | (new_width, new_height, offset_x, offset_y) |
| 178 | """ |
| 179 | img_ratio = img_width / img_height |
| 180 | box_ratio = box_width / box_height |
| 181 | |
| 182 | if mode == 'meet': |
| 183 | # Fully display image, may have whitespace |
| 184 | if img_ratio > box_ratio: |
| 185 | # Image is wider, fit by width |
| 186 | new_width = box_width |
| 187 | new_height = box_width / img_ratio |
| 188 | else: |
| 189 | # Image is taller, fit by height |
| 190 | new_height = box_height |
| 191 | new_width = box_height * img_ratio |
| 192 | else: # slice |
| 193 | # Fully fill container, may crop |
| 194 | if img_ratio > box_ratio: |
| 195 | # Image is wider, fit by height |
| 196 | new_height = box_height |
| 197 | new_width = box_height * img_ratio |
| 198 | else: |
| 199 | # Image is taller, fit by width |
| 200 | new_width = box_width |
| 201 | new_height = box_width / img_ratio |
| 202 | |
| 203 | # Center offset |
| 204 | offset_x = (box_width - new_width) / 2 |
| 205 | offset_y = (box_height - new_height) / 2 |
| 206 | |
| 207 | return new_width, new_height, offset_x, offset_y |
| 208 | |
| 209 | |
| 210 | def fix_image_aspect_in_svg(svg_path: str, dry_run: bool = False, verbose: bool = True) -> int: |
| 211 | """ |
| 212 | Fix image aspect ratios in an SVG file. |
| 213 | |
| 214 | Args: |
| 215 | svg_path: SVG file path |
| 216 | dry_run: Whether to only preview without modifying |
| 217 | verbose: Whether to output detailed information |
| 218 | |
| 219 | Returns: |
| 220 | Number of images fixed |
| 221 | """ |
| 222 | svg_dir = os.path.dirname(os.path.abspath(svg_path)) |
| 223 | |
| 224 | with open(svg_path, 'r', encoding='utf-8') as f: |
| 225 | content = f.read() |
| 226 | |
| 227 | # Register SVG namespaces |
| 228 | namespaces = { |
| 229 | '': 'http://www.w3.org/2000/svg', |
| 230 | 'xlink': 'http://www.w3.org/1999/xlink', |
| 231 | 'svg': 'http://www.w3.org/2000/svg', |
| 232 | 'sodipodi': 'http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd', |
| 233 | 'inkscape': 'http://www.inkscape.org/namespaces/inkscape', |
| 234 | } |
| 235 | |
| 236 | for prefix, uri in namespaces.items(): |
| 237 | if prefix: |
| 238 | ET.register_namespace(prefix, uri) |
| 239 | else: |
| 240 | ET.register_namespace('', uri) |
| 241 | |
| 242 | try: |
| 243 | tree = ET.parse(svg_path) |
| 244 | root = tree.getroot() |
| 245 | except ET.ParseError as e: |
| 246 | print(f" [ERROR] Cannot parse SVG: {e}") |
| 247 | return 0 |
| 248 | |
| 249 | # Find all image elements |
| 250 | fixed_count = 0 |
| 251 | |
| 252 | # Check image elements with and without namespace |
| 253 | for ns_prefix in ['', '{http://www.w3.org/2000/svg}']: |
| 254 | for image_elem in root.iter(f'{ns_prefix}image'): |
| 255 | # Get href attribute (supports xlink:href and href) |
| 256 | href = image_elem.get('{http://www.w3.org/1999/xlink}href') |
| 257 | if href is None: |
| 258 | href = image_elem.get('href') |
| 259 | if href is None: |
| 260 | continue |
| 261 | |
| 262 | # Get current dimensions and position |
| 263 | try: |
| 264 | x = float(image_elem.get('x', 0)) |
| 265 | y = float(image_elem.get('y', 0)) |
| 266 | width = float(image_elem.get('width', 0)) |
| 267 | height = float(image_elem.get('height', 0)) |
| 268 | except (ValueError, TypeError): |
| 269 | continue |
| 270 | |
| 271 | if width <= 0 or height <= 0: |
| 272 | continue |
| 273 | |
| 274 | # Get preserveAspectRatio |
| 275 | par = image_elem.get('preserveAspectRatio', 'xMidYMid meet') |
| 276 | |
| 277 | # Parse preserveAspectRatio |
| 278 | # Format: <align> [<meetOrSlice>] |
| 279 | # e.g.: xMidYMid meet, xMidYMid slice, none |
| 280 | par_parts = par.split() |
| 281 | align = par_parts[0] if par_parts else 'xMidYMid' |
| 282 | meet_or_slice = par_parts[1] if len(par_parts) > 1 else 'meet' |
| 283 | |
| 284 | if align == 'none': |
| 285 | # If none, no fix needed |
| 286 | continue |
| 287 | |
| 288 | # Get original image dimensions |
| 289 | img_width, img_height = get_image_dimensions(href, svg_dir) |
| 290 | if img_width is None or img_height is None: |
| 291 | continue |
| 292 | |
| 293 | # Calculate fitted dimensions |
| 294 | mode = 'slice' if meet_or_slice == 'slice' else 'meet' |
| 295 | new_width, new_height, offset_x, offset_y = calculate_fitted_dimensions( |
| 296 | img_width, img_height, width, height, mode |
| 297 | ) |
| 298 | |
| 299 | # Check if modification is needed |
| 300 | tolerance = 0.5 # Allowed tolerance |
| 301 | if (abs(new_width - width) < tolerance and |
| 302 | abs(new_height - height) < tolerance): |
| 303 | # Dimensions are already correct, no modification needed |
| 304 | continue |
| 305 | |
| 306 | if verbose: |
| 307 | img_name = os.path.basename(href.split('?')[0][:50] if not href.startswith('data:') else '[base64]') |
| 308 | print(f" [FIX] {img_name}") |
| 309 | print(f" Original image: {img_width}x{img_height} (ratio: {img_width/img_height:.3f})") |
| 310 | print(f" Original box: {width}x{height} @ ({x}, {y})") |
| 311 | print(f" New box: {new_width:.1f}x{new_height:.1f} @ ({x + offset_x:.1f}, {y + offset_y:.1f})") |
| 312 | |
| 313 | if not dry_run: |
| 314 | # Update attributes |
| 315 | image_elem.set('x', f'{x + offset_x:.1f}') |
| 316 | image_elem.set('y', f'{y + offset_y:.1f}') |
| 317 | image_elem.set('width', f'{new_width:.1f}') |
| 318 | image_elem.set('height', f'{new_height:.1f}') |
| 319 | # Remove preserveAspectRatio since dimensions are now correct |
| 320 | if 'preserveAspectRatio' in image_elem.attrib: |
| 321 | del image_elem.attrib['preserveAspectRatio'] |
| 322 | |
| 323 | fixed_count += 1 |
| 324 | |
| 325 | if not dry_run and fixed_count > 0: |
| 326 | # Save modifications |
| 327 | tree.write(svg_path, encoding='unicode', xml_declaration=True) |
| 328 | |
| 329 | return fixed_count |
| 330 | |
| 331 | |
| 332 | def main() -> None: |
| 333 | """Run the CLI entry point.""" |
| 334 | parser = argparse.ArgumentParser( |
| 335 | description='Normalize SVG image boxes for PowerPoint SVG rendering diagnostics', |
| 336 | formatter_class=argparse.RawDescriptionHelpFormatter, |
| 337 | epilog=''' |
| 338 | Examples: |
| 339 | %(prog)s slide_01.svg # Process a single file |
| 340 | %(prog)s *.svg # Process all SVGs in current directory |
| 341 | %(prog)s --dry-run *.svg # Preview files to be processed |
| 342 | %(prog)s projects/xxx/svg_output/*.svg # Process project directory |
| 343 | ''' |
| 344 | ) |
| 345 | parser.add_argument('files', nargs='+', help='SVG files to process') |
| 346 | parser.add_argument('--dry-run', '-n', action='store_true', |
| 347 | help='Only show which images would be fixed, without modifying files') |
| 348 | parser.add_argument('--quiet', '-q', action='store_true', |
| 349 | help='Quiet mode, reduce output') |
| 350 | |
| 351 | args = parser.parse_args() |
| 352 | |
| 353 | if args.dry_run: |
| 354 | print("[INFO] Preview mode: only showing what would be modified, no files will be changed\n") |
| 355 | |
| 356 | total_fixed = 0 |
| 357 | total_files = 0 |
| 358 | |
| 359 | for svg_file in args.files: |
| 360 | if not os.path.exists(svg_file): |
| 361 | if not args.quiet: |
| 362 | print(f"[ERROR] File not found: {svg_file}") |
| 363 | continue |
| 364 | |
| 365 | if not svg_file.endswith('.svg'): |
| 366 | if not args.quiet: |
| 367 | print(f"[SKIP] Skipping non-SVG file: {svg_file}") |
| 368 | continue |
| 369 | |
| 370 | if not args.quiet: |
| 371 | print(f"\n[FILE] {os.path.basename(svg_file)}") |
| 372 | |
| 373 | fixed = fix_image_aspect_in_svg(svg_file, dry_run=args.dry_run, verbose=not args.quiet) |
| 374 | |
| 375 | if fixed > 0: |
| 376 | total_fixed += fixed |
| 377 | total_files += 1 |
| 378 | elif not args.quiet: |
| 379 | print(" No fix needed") |
| 380 | |
| 381 | print(f"\n{'=' * 50}") |
| 382 | if args.dry_run: |
| 383 | print(f"[PREVIEW] Will fix {total_fixed} image(s) in {total_files} file(s)") |
| 384 | else: |
| 385 | print(f"[DONE] Fixed {total_fixed} image(s) in {total_files} file(s)") |
| 386 | |
| 387 | |
| 388 | if __name__ == '__main__': |
| 389 | main() |
| 390 |