Okay, so I’m trying to make an image resizer with flask and Pillow and I am done with the 1st two parts:

1. Show user uploaded images with Dropzone
2. Save user uploaded image as it is for now into a static folder

Now, I want to resize these images before saving them. For resizing them I have a form that gets width and height from the user.

Html code –

<form>
    <p>IN PIXELS</p>
    <label for="width">Width - </label>
    <input type="number" id="width" name="width" value="width">
    <label for="height">Height - </label>
    <input type="number" id="height" name="height" value="width">
    <input type="submit" id="submit">
  </form>

Script that gets user image –

@app.route('/', methods=['GET', 'POST'])
def retrieve_images():
    if request.method == 'POST':
        file = request.files['file']
        filename = secure_filename(file.filename)
        if filename != '':
            file_ext = os.path.splitext(filename)[1]
            if file_ext not in app.config['UPLOAD_EXTENSIONS'] or 
            file_ext != validate_image(file.stream):
                return 'Invalid Image', 404
            img_file = Image.open(file)
            width = request.form.get("width")
            height = request.form.get("height")
            res_img = img_file.resize((width, height), Image.LANCZOS)
        return res_img.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
    return render_template('index.html')

And, I have this type error –
return self._new(self.im.resize(size, resample, box))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: ‘NoneType’ object cannot be interpreted as an integer

I tried to search online but could not find any relevant answer to this.