enter image description here
I have built a tool to repair encrypted JPEG files affected by stop/djvu ransomware. It encrypts 153605 bytes from the header. However, when I shift the MCU to fix alignment, the left column appears distorted and glitches up by one MCU in the column.
After moving the good header to the encrypted JPEG header…
enter image description here
The bottom has both good and non-MCU sections
enter image description here
After counting the number of non-MCU units from those bottom scanlines to shift the MCU, upon shifting to correct alignment, the left column becomes distorted and glitches up by one MCU in the column.
enter image description here
Can you help me to fix my code?
import sys
import os
import re
import numpy as np
from PyQt6.QtWidgets import QApplication, QWidget, QVBoxLayout, QPushButton, QFileDialog, QTextEdit, QLabel, QLineEdit
from PyQt6.QtCore import Qt
from PIL import Image, ImageOps, ImageEnhance
class JpegToolGUI(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
self.setWindowTitle("JPEG Repair Tool")
self.setGeometry(100, 100, 400, 400)
self.setStyleSheet('''
QPushButton {
background-color: #007ACC;
color: white;
border: none;
border-radius: 5px;
padding: 8px 16px;
}
QPushButton:hover {
background-color: #005F99;
}
QTextEdit {
background-color: #D9E6F5;
color: black;
border-radius: 5px;
padding: 8px;
}
''')
self.layout = QVBoxLayout()
# Create buttons
self.btnSelectReference = QPushButton("Select Reference JPEG")
self.btnSelectEncryptedFolder = QPushButton("Select Encrypted Folder")
self.btnRepairJpeg = QPushButton("Repair JPEGs")
self.btnShiftMcu = QPushButton("Shift MCU")
self.btnAutoColor = QPushButton("Auto Color")
# Create text output area
self.outputText = QTextEdit()
self.outputText.setReadOnly(True)
# Create input fields
self.reference_jpeg_input = QLineEdit()
self.encrypted_folder_input = QLineEdit()
# Add widgets to layout
self.layout.addWidget(QLabel("Reference JPEG:"))
self.layout.addWidget(self.reference_jpeg_input)
self.layout.addWidget(self.btnSelectReference)
self.layout.addWidget(QLabel("Encrypted Folder:"))
self.layout.addWidget(self.encrypted_folder_input)
self.layout.addWidget(self.btnSelectEncryptedFolder)
self.layout.addWidget(self.btnRepairJpeg)
self.layout.addWidget(self.btnShiftMcu)
self.layout.addWidget(self.btnAutoColor)
self.layout.addWidget(self.outputText)
self.setLayout(self.layout)
# Connect button actions
self.btnSelectReference.clicked.connect(self.selectReferenceJPEG)
self.btnSelectEncryptedFolder.clicked.connect(self.selectEncryptedFolder)
self.btnRepairJpeg.clicked.connect(self.repairJPEGs)
self.btnShiftMcu.clicked.connect(self.shift_mcu)
self.btnAutoColor.clicked.connect(self.autoColorImages)
def selectReferenceJPEG(self):
fileName, _ = QFileDialog.getOpenFileName(self, "Select Reference JPEG", "", "JPEG Files (*.jpg);;All Files (*)")
if fileName:
self.reference_jpeg_input.setText(fileName)
def selectEncryptedFolder(self):
folderName = QFileDialog.getExistingDirectory(self, "Select Encrypted Folder")
if folderName:
self.encrypted_folder_input.setText(folderName)
def repairJPEGs(self):
reference_jpeg = self.reference_jpeg_input.text().strip()
encrypted_folder = self.encrypted_folder_input.text().strip()
if not os.path.exists(reference_jpeg) or not os.path.exists(encrypted_folder):
self.outputText.append("Please select the reference JPEG and encrypted folder.")
return
repaired_folder = os.path.join(encrypted_folder, "Repaired")
if not os.path.exists(repaired_folder):
os.makedirs(repaired_folder)
pattern = re.compile(r".*.JPG..{4}$", re.I)
for encrypted_file in os.listdir(encrypted_folder):
if pattern.match(encrypted_file): # Matches files like *.JPG.****
output_file = os.path.join(repaired_folder, os.path.splitext(encrypted_file)[0].rsplit('.', 1)[0] + '.JPG')
offset = self.find_jpeg_markers(reference_jpeg, 'ECS')
self.dd_replacement(reference_jpeg, output_file, bs=1, count=offset)
self.dd_replacement(os.path.join(encrypted_folder, encrypted_file), output_file, bs=1024, skip=153605)
self.outputText.append(f"Processed {encrypted_file} to {output_file}")
self.outputText.append("Repair complete.")
def find_jpeg_markers(self, filename, marker=None):
with open(filename, "rb") as f:
s = f.read()
marker_name = {
0xd8: "SOI", 0xe0: "APP0", 0xe1: "APP1", 0xdb: "DQT",
0xc0: "SOF", 0xc4: "DHT", 0xda: "SOS", 0xd9: "EOI",
0: "ECS"
}
segments = {}
offset = 0
while True:
f = s.find(b"xff", offset)
if f < 0:
break
offset = f + 2
if offset <= len(s):
m = s[f + 1]
if m in marker_name:
segments[f] = m
if marker and marker.upper() == "ECS":
last_sos_offset = None
for f in reversed(sorted(segments.keys())):
if marker_name[segments[f]] == "SOS":
last_sos_offset = f
break
if last_sos_offset is not None:
return last_sos_offset + 12
elif marker:
for f in reversed(sorted(segments.keys())):
if marker_name[segments[f]] == marker.upper():
return f
else:
offsets = [(marker_name[segments[f]], f) for f in sorted(segments.keys())]
return offsets
def dd_replacement(self, input_file, output_file, bs=1, count=None, skip=None):
with open(input_file, "rb") as f:
if skip:
f.seek(skip)
data = f.read(bs * count if count else -1)
with open(output_file, "ab") as f:
f.write(data)
def autoColorImages(self):
repaired_folder = os.path.join(self.encrypted_folder_input.text().strip(), "Repaired")
if not os.path.exists(repaired_folder):
self.outputText.append("Repaired folder not found.")
return
jpg_files = [f for f in os.listdir(repaired_folder) if f.lower().endswith(".jpg")]
if not jpg_files:
self.outputText.append("No JPG files found in the Repaired folder.")
return
for jpg_file in jpg_files:
image_path = os.path.join(repaired_folder, jpg_file)
try:
im = Image.open(image_path)
im = ImageOps.autocontrast(im, cutoff=1)
enhancer = ImageEnhance.Sharpness(im).enhance(3)
im = ImageOps.posterize(im, bits=8)
enhancer = ImageEnhance.Color(im).enhance(3)
im.save(image_path, quality="maximum")
self.outputText.append(f"Auto color applied to {jpg_file} and saved.")
except Exception as e:
self.outputText.append(f"Error processing image {jpg_file}: {str(e)}")
self.outputText.append("Auto Color process complete.")
def shift_mcu(self):
reference_jpeg = self.reference_jpeg_input.text().strip()
encrypted_folder = self.encrypted_folder_input.text().strip()
if not os.path.exists(reference_jpeg) or not os.path.exists(encrypted_folder):
self.outputText.append("Please select the reference JPEG and encrypted folder.")
return
repaired_folder = os.path.join(encrypted_folder, "Repaired")
if not os.path.exists(repaired_folder):
self.outputText.append("Repaired folder not found. Run Repair JPEGs first.")
return
jpg_files = [f for f in os.listdir(repaired_folder) if f.lower().endswith(".jpg")]
if not jpg_files:
self.outputText.append("No JPG files found in the Repaired folder.")
return
for jpg_file in jpg_files:
image_path = os.path.join(repaired_folder, jpg_file)
try:
img = Image.open(image_path)
data = np.array(img, dtype=np.uint8)
except Exception as e:
self.outputText.append(f"Error opening image {jpg_file}: {str(e)}")
continue
num_good_mcu = self.auto_detect_shift(data)
if num_good_mcu == 0:
self.outputText.append(f"No MCU shift needed for {jpg_file}.")
continue
width_to_shift = num_good_mcu * 8
shifted_data = np.hstack((data[:, width_to_shift:], data[:, :width_to_shift]))
height, width, _ = shifted_data.shape
while height >= 8 and np.array_equal(shifted_data[height - 8:height, :, :], np.ones((8, width, 3), dtype=np.uint8) * 128):
height -= 8
height -= 8
width -= 16
cropped_data = shifted_data[:height, :width, :]
output_img = Image.fromarray(cropped_data)
output_img.save(image_path, "JPEG")
self.outputText.append(f"Shifted and saved image {jpg_file} to: {image_path}")
self.outputText.append("MCU Shift process complete.")
def auto_detect_shift(self, data):
block_size = 8
height, width, _ = data.shape
while height >= block_size:
if np.array_equal(data[height - block_size:height, :, :], np.ones((block_size, width, 3), dtype=np.uint8) * 128):
height -= block_size
else:
break
cropped_data = data[:height, :, :]
for j in range(0, width, block_size):
mcu = cropped_data[height - block_size:height, j:j + block_size, :]
gray_mcu = np.ones((block_size, block_size, 3), dtype=np.uint8) * 128
diff = np.abs(mcu.astype(int) - gray_mcu.astype(int))
avg_diff = np.mean(diff)
if avg_diff < 10:
return j // block_size
return width // block_size
def main():
app = QApplication(sys.argv)
window = JpegToolGUI()
window.show()
sys.exit(app.exec())
if __name__ == "__main__":
main()
I need help to fix code for this issue