I created the script to resize thousands images in a single-run Python command in Linux (Ubuntu). This will also work in Windows i guess. It can resize thousands of images ( I run it before for > 50K images)

Suppose we have images stored in Folder structures like this :

images

---- Tigers

-------------1_tigers.jpg

-------------2_tigers.jpg



-------------2_tigers.png



-------------n_tigers.jpg



---- Cats

-------------1_cats.jpg

-------------2_tcats.jpg

-------------2_cats.png

-------------n_cats.jpg

---- n

-------------1_n.jpg

-------------2_n.jpg

-------------3_n.png

-------------n_n.jpg

.............................

ans so on.

Run the script with this steps :

1. Open your terminal, and type

2. python resizer.py {img source folder} {the size you want the image to be} {destination folder}

example :

python resizer.py /home/ubuntu/images/ 128 /home/ubuntu/new_images

3. Drink your coffee and watch the terminal running the process

Notes:

1. Install PIL image if you dont have one ( another library considered faster than this)

2. ANTIALIAS and quality=90 is to prevent the image from downgrading quality for Down-Scalling

3. This code works for Down-Scalling resize , yo can use another method beside ANTIALIAS for Free-Scalling

4. Images will be converted to .jpg extension ( its up to you, you can change it your way)

5. If you have different folder structures from above example, modify the code

import PIL from PIL import Image import os import sys def readf(): try: input_dir = str(sys.argv[1].rstrip('/')) #path to img source folder img_size = str(sys.argv[2]) #The image size (128, 256,etc) output_dir = str(sys.argv[3].rstrip('/')) #output directory print "starting...." print "Colecting data from %s " % input_dir tclass = [ d for d in os.listdir( input_dir ) ] counter = 0 strdc = '' hasil = [] for x in tclass: list_dir = os.path.join(input_dir, x ) list_tuj = os.path.join(output_dir+'/', x+'/') if not os.path.exists(list_tuj): os.makedirs(list_tuj) if os.path.exists(list_tuj): for d in os.listdir(list_dir): try: img = Image.open(os.path.join(input_dir+'/'+x,d)) img = img.resize((int(img_size),int(img_size)),Image.ANTIALIAS) fname,extension = os.path.splitext(d) newfile = fname+extension if extension != ".jpg" : newfile = fname + ".jpg" img.save(os.path.join(output_dir+'/'+x,newfile),"JPEG",quality=90) print "Resizing file : %s - %s " % (x,d) except Exception,e: print "Error resize file : %s - %s " % (x,d) sys.exit(1) counter +=1 except Exception,e: print "Error, check Input directory etc : ", e sys.exit(1) readf()