feat: Add app

pdf_converter.py

@@ -0,0 +1,46 @@
+import numpy as np
+from pdf2image import convert_from_bytes, convert_from_path
+from PIL import Image
+
+
+class PdfConverter:
+    """
+    A service to convert PDF files to images and resize images,
+    using pypdfium2 for PDFs and Pillow for images.
+    """
+
+    def __init__(self, dpi: int):
+        self._pdfium_initialized = False  # Track if PDFium needs explicit init/deinit
+        self._dpi = dpi
+
+    def convert_pdf_to_jpg(self, file_path: str) -> list[Image.Image]:
+        """
+        Converts a PDF file to JPG images at different scales.
+        """
+        pil_images = convert_from_path(file_path, dpi=self._dpi)
+        return pil_images
+
+    def resize_image(self, img: Image.Image, size: tuple[int, int]) -> Image.Image:
+        """
+        Resizes a PIL Image to the specified size.
+        """
+        return img.resize(size, Image.LANCZOS)
+
+    @staticmethod
+    def save_image_as_png(img: Image.Image, file_path: str):
+        """
+        Saves a PIL Image as a PNG file.
+        """
+        img.save(file_path, format="PNG")
+
+    @staticmethod
+    def to_cv2_image(img: Image.Image):
+        open_cv_image = np.array(img.convert("RGB"))
+        return open_cv_image[:, :, ::-1].copy()
+
+    def convert_pdf_bytes_to_jpg(self, pdf_bytes: bytes) -> list[Image.Image]:
+        """
+        Converts PDF bytes to JPG images at different scales.
+        """
+        pil_images = convert_from_bytes(pdf_bytes, dpi=self._dpi)
+        return pil_images