Beak
c05be82766
got the json data out of the files and somewhat into the app. Need to customize the data display.
87 lines
3.5 KiB
Python
87 lines
3.5 KiB
Python
# extract_chunks.py
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import struct
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import sys
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import os
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def extract_png_text_chunks(file_path):
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"""Extract only text chunks from PNG and print them"""
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print(f"🔍 Attempting to read: {file_path}")
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print(f" File exists: {os.path.exists(file_path)}")
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print(f" File size: {os.path.getsize(file_path) if os.path.exists(file_path) else 'N/A'} bytes")
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try:
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with open(file_path, 'rb') as f:
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signature = f.read(8)
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print(f"📄 PNG signature: {signature.hex()}")
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if signature != b'\x89PNG\r\n\x1a\n':
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print("❌ Not a valid PNG file")
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return
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print(f"✅ Valid PNG file detected")
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print("🔍 Scanning for chunks...")
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text_chunks = []
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chunk_count = 0
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while True:
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length_data = f.read(4)
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if not length_data:
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print("📄 End of file reached")
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break
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chunk_length = struct.unpack('>I', length_data)[0]
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chunk_type = f.read(4).decode('ascii')
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chunk_data = f.read(chunk_length)
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f.read(4) # Skip CRC
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chunk_count += 1
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print(f" Chunk #{chunk_count}: {chunk_type} ({chunk_length} bytes)")
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if chunk_type in ['tEXt', 'iTXt', 'zTXt']:
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print(f" ✅ Found text chunk: {chunk_type}")
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try:
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if chunk_type == 'tEXt':
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parts = chunk_data.split(b'\x00', 1)
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if len(parts) == 2:
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keyword = parts[0].decode('latin-1')
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text = parts[1].decode('latin-1')
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text_chunks.append((chunk_type, keyword, text))
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print(f" Keyword: '{keyword}', Text length: {len(text)}")
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else:
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hex_preview = chunk_data[:100].hex()
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text_chunks.append((chunk_type, "raw_data", hex_preview))
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print(f" Raw data (hex): {hex_preview}...")
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except Exception as e:
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print(f" Decode error: {e}")
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text_chunks.append((chunk_type, "binary_data", "Could not decode"))
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if chunk_type == 'IEND':
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print("📄 IEND chunk - end of PNG data")
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break
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print(f"\n📊 Summary: Found {len(text_chunks)} text chunks out of {chunk_count} total chunks")
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if text_chunks:
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print("\n" + "=" * 50)
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print("TEXT CHUNKS FOUND:")
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print("=" * 50)
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for chunk_type, keyword, content in text_chunks:
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print(f"Chunk: {chunk_type}")
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print(f"Keyword: {keyword}")
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print(f"Content: {content}")
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print("-" * 30)
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else:
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print("❌ No text chunks found in PNG")
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except Exception as e:
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print(f"❌ Error reading file: {e}")
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if __name__ == "__main__":
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if len(sys.argv) > 1:
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extract_png_text_chunks(sys.argv[1])
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else:
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print("Usage: python extract_chunks.py <png_file>")
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print("Example: python extract_chunks.py my_image.png")
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