Thumbnail creator

image_to_thumbnail.py

# -*- coding: utf-8 -*-
"""
Created on Sat May 26 09:10:40 2018

@author: David O'Dell
"""
# Simple script that resizes all images in a directory to 100 x 100 thumbnails"
# script needs to be placed inside target directory

# import libraries

import cv2
import sys
import glob

# to make this more robust and find other image file types one would want to 
# iterate through a list of common graphics extensions

def get_file_list():
    extension_list = ["*.jpg", "*.jpeg", "*.gif", "*.bmp", "*.png", "*.tiff", "*.tif"]
    file_list = []
    for i in extension_list:
        file_list.extend(glob.glob(i))  
    get_input(file_list)  # send the file list to the function that gets user input


# Since the directory could be filled with thousands of images, we should probably
# ask the user how they want to proceed with the job
        
def get_input(file_list):    
    
    user_in = input("List files - L  Convert files - C  Quit - any other key:  ")
    
    if user_in == "L":
        print("\r\n" + str(len(file_list)) + " files found that match commmon graphic extensions are:\r\n")
        for file in file_list:
            print(file)
        get_input(file_list)
        
    elif user_in == "C":
        convert(file_list)
        print("\r\n" + str(len(file_list)) + " files successfully converted.")
        sys.exit()
        
    else:
        print("Bye!")
        sys.exit()


# define a function that can resize an image to 100 x 100 then write to a new filename

def convert(file_list):
        
    # cv2.imread can read in different modes, 0 grey, 1 color, -1 alpha transparency

    for i in file_list:
        file_name = str(i)
        img = cv2.imread(file_name, 1)
        resized_image = cv2.resize(img, (100, 100))
        new_file_name = "RESIZED_" + file_name
        cv2.imwrite(new_file_name, resized_image)    
        print(new_file_name)


# call the initial function

get_file_list()