One task I use Python to perform on my desktop is image manipulation. Although there are plenty of good image processor utilities (i.e. IrfanView and XnView) sometimes it is simply quicker to create a Python script to complete a particular task for you.
By importing the Image library and making use of the resize function images can be resized to a specified size. It supports all common image formats such as PNG, GIF, JPG and BMP.
The basics of image resizing are shown below :
# Import the PIL image library import Image # Import os library for file manipulation functions import os # Open an image file (.bmp,.jpg,.png,.gif) myimagefile = "myphoto.jpg" myimage = Image.open(myimagefile) # Set new width and height width_new = 800 height_new = 600 # Choose resize filter to use. filter = Image.ANTIALIAS # Resize the image newimage = myimage.resize((width_new, height_new), filter) # Split filename filename, extension = os.path.splitext(myimagefile) # Save the image newimage.save(filename + "_resized" + extension)
The other filters available when resizing are :
Image.ANTIALIAS works fine for me so I tend to use that for resizing images.
The “newimage.save” function saves the file in the format determined by the file extension. In this case JPEG.
This example can be used as the basis for a script that resizes a directory full of images. It can be formed into a function which can be called within a loop that acts on each image in turn.