Update the webcame and printing image part

src/main.py

@@ -50,7 +50,7 @@ if os.getenv('LIPY_DEBUG') == True:
 app.secret_key = configuration_file["secrets"]["flask_secret_key"]
 app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
 app.config['ALLOWED_EXTENSIONS'] = ALLOWED_EXTENSIONS
-app.config['MAX_CONTENT_LENGTH'] = 3 * 1000 * 1000 # Maximum 3Mb for a file upload
+app.config['MAX_CONTENT_LENGTH'] = 10 * 1000 * 1000 # Maximum 3Mb for a file upload
 app.config['TEMPLATES_AUTO_RELOAD'] = True
 
 # Printer connection

src/printer.py

@@ -3,7 +3,8 @@ from flask import flash
 from escpos.printer import Usb, USBNotFoundError
 from time import sleep, gmtime, strftime
 import os.path
-from PIL import Image
+from PIL import Image, ImageEnhance, ImageOps
+import numpy as np
 
 
 class Printer(object):
@@ -138,6 +139,12 @@ class Printer(object):
     def print_img(self, path, sign):
         clean_signature = str(sign)
 
+        if len(clean_signature) > 256 or len(clean_signature) < 3:
+            self.app.logger.warning("Could not print message without a signature.")
+            flash("Could not print message without a signature.",category='error')
+            return False
+
+
         if not os.path.isfile(str(path)):
             self.app.logger.warning("File does not exist : " + str(path))
             flash('The file path for this image :' + str(path) + " wasn't found. Please try again.", 'error')
@@ -145,21 +152,9 @@ class Printer(object):
         else:
             self.app.logger.debug("Printing file from " + str(path))
 
-
-
         try:
-            self.app.logger.debug("Resizing the image")
-            with Image.open(path) as im:
-
-                basewidth = 575
-                img = Image.open(path)
-                wpercent = (basewidth/float(img.size[0]))
-                hsize = int((float(img.size[1])*float(wpercent)))
-                img = img.resize((basewidth,hsize), Image.ANTIALIAS)
-                if img.height > 1000:
-                    flash("Image is too long, sorry ! Keep it below 500×1000 pixels.",'error')
-                    return False
-                img.save(path)
+            self.app.logger.debug("Proccessing the image")
+            path = process_image(self, path)
         except Exception as e:
             flash(str(e))
             self.app.logger.error(str(e))
@@ -178,3 +173,53 @@ class Printer(object):
             self.printer.close()
             flash(str(e),'error')
             return False
+
+def process_image(self, path):
+    brightness_factor = 1.5  # Used only if image is too dark
+    brightness_threshold = 150  # Brightness threshold (0–255)
+    contrast_factor = 0.8         # Less than 1.0 = lower contrast
+    max_width = 575
+    max_height = 1000
+
+    with Image.open(path) as original_img:
+        # Convert to RGB if needed (JPEG doesn't support alpha)
+        if original_img.mode in ("RGBA", "P"):
+            self.app.logger.debug("Converting the image to RGB from RGBA")
+            original_img = original_img.convert("RGB")
+
+        # Resize while maintaining aspect ratio
+        original_img.thumbnail((max_width, max_height), Image.LANCZOS)
+        self.app.logger.debug("Resized the image")
+
+        # Convert to grayscale for dithering
+        dithered_img = original_img.convert("L").convert("1")  # Dithering using default method (Floyd–Steinberg)
+        self.app.logger.debug("Dithered the image")
+
+        # Compute brightness of original image (grayscale average)
+        grayscale = original_img.convert("L")
+        avg_brightness = np.array(grayscale).mean()
+        self.app.logger.debug("Average brightness of the image : " + str(avg_brightness) )
+
+        # Dynamically compute brightness factor if too dark
+        if avg_brightness < brightness_threshold:
+            brightness_factor = 1 + (brightness_threshold - avg_brightness) / brightness_threshold
+            brightness_factor = min(max(brightness_factor, 1.1), 2.5)  # Clamp between 1.1 and 2.5
+            self.app.logger.debug(f"Image too dark, increasing brightness by a factor of {brightness_factor:.2f}")
+            enhancer = ImageEnhance.Brightness(original_img)
+            original_img = enhancer.enhance(brightness_factor)
+
+        # Reduce contrast
+        contrast_enhancer = ImageEnhance.Contrast(original_img)
+        original_img = contrast_enhancer.enhance(contrast_factor)
+
+        # Final resize check
+        if original_img.height > max_height:
+            flash("Image is too long, sorry! Keep it below 575×1000 pixels.", 'error')
+            self.app.logger.error("Image is too long, sorry! Keep it below 575×1000 pixels.")
+            return False
+
+        # Convert to JPEG and save
+        jpeg_path = os.path.splitext(path)[0] + "_processed.jpg"
+        original_img.save(jpeg_path, format='JPEG', quality=95, optimize=True)
+
+    return jpeg_path

src/static/js/webcam.js

@@ -132,7 +132,7 @@ function print_picture(data){
     // headers:{
     //   'Content-Type': 'multipart/form-data'
     // }
-  }).then(function(response) { console.log('Success:', response); alert("Picture printed."); } , true)
+  }).then(function(response) { console.log('Success:', response); } , true)
   .catch(error => console.error('Error:', error), false);
 
 }