Add OCR and image correction

backend/app/backends/common.py

@@ -0,0 +1,16 @@
+from PIL import Image
+import ocrmypdf
+
+def create_pdf(scanner):
+    images = []
+    for page in scanner.get_pages():
+        img = Image.open(f"/var/www/html/img/{page.filename}")
+        a4im = Image.new('RGB',
+                 (int(210 * 200 / 25.4), int(297 * 200 / 25.4)),
+                 (255, 255, 255))
+        a4im.paste(img, img.getbbox())
+        images.append(a4im)
+    images[0].save("/var/www/html/img/out.pdf", save_all=True, append_images=images[1:])
+
+def ocr_pdf():
+    ocrmypdf.ocr('/var/www/html/img/out.pdf', '/var/www/html/img/final.pdf')