Working with Images in Python (original) (raw)
Last Updated : 4 Jun, 2024
PIL is the Python Imaging Library which provides the python interpreter with image editing capabilities. It was developed by Fredrik Lundh and several other contributors. Pillow is the friendly PIL fork and an easy to use library developed by Alex Clark and other contributors. We’ll be working with Pillow.
**Installation:
- **Linux: On linux terminal type the following:
pip install Pillow
Installing pip via terminal:
sudo apt-get update
sudo apt-get install python-pip - **Windows: Download the appropriate Pillow package according to your python version. Make sure to download according to the python version you have.
We’ll be working with the Image Module here which provides a class of the same name and provides a lot of functions to work on our images.To import the Image module, our code should begin with the following line:
from PIL import Image
**Operations with Images:
- **Open a particular image from a path: Python `
#img = Image.open(path)
On successful execution of this statement,
an object of Image type is returned and stored in img variable)
try:
img = Image.open(path)
except IOError:
pass
Use the above statement within try block, as it can
raise an IOError if file cannot be found,
or image cannot be opened.
`
- **Retrieve size of image: The instances of Image class that are created have many attributes, one of its useful attribute is size. Python `
from PIL import Image
filename = "image.png"
with Image.open(filename) as image:
width, height = image.size
#Image.size gives a 2-tuple and the width, height can be obtained
` Some other attributes are: Image.width, Image.height, Image.format, Image.info etc.
- **Save changes in image: To save any changes that you have made to the image file, we need to give path as well as image format. Python `
img.save(path, format)
format is optional, if no format is specified,
#it is determined from the filename extension
`
- **Rotating an Image: The image rotation needs angle as parameter to get the image rotated. Python `
from PIL import Image
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
#Angle given
img = img.rotate(180)
#Saved in the same relative location
img.save("rotated_picture.jpg")
except IOError:
pass
if name == "main":
main()
` 
Note: There is an optional expand flag available as one of the argument of the rotate method, which if set true, expands the output image to make it large enough to hold the full rotated image. As seen in the above code snippet, I have used a relative path where my image is located in the same directory as my python code file, an absolute path can be used as well.
- **Cropping an Image: Image.crop(box) takes a 4-tuple (left, upper, right, lower) pixel coordinate, and returns a rectangular region from the used image. Python `
from PIL import Image
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
width, height = img.size
area = (0, 0, width/2, height/2)
img = img.crop(area)
#Saved in the same relative location
img.save("cropped_picture.jpg")
except IOError:
pass
if name == "main":
main()
` 
- **Resizing an Image: Image.resize(size)- Here size is provided as a 2-tuple width and height. Python `
from PIL import Image
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
width, height = img.size
img = img.resize((width/2, height/2))
#Saved in the same relative location
img.save("resized_picture.jpg")
except IOError:
pass
if name == "main":
main()
` 
- **Pasting an image on another image: The second argument can be a 2-tuple (specifying the top left corner), or a 4-tuple (left, upper, right, lower) - in this case the size of pasted image must match the size of this box region, or None which is equivalent to (0, 0). Python `
from PIL import Image
def main():
try:
#Relative Path
#Image on which we want to paste
img = Image.open("picture.jpg")
#Relative Path
#Image which we want to paste
img2 = Image.open("picture2.jpg")
img.paste(img2, (50, 50))
#Saved in the same relative location
img.save("pasted_picture.jpg")
except IOError:
pass
if name == "main":
main()
##An additional argument for an optional image mask image is also available.
` 
- **Getting a Histogram of an Image: This will return a histogram of the image as a list of pixel counts, one for each pixel in the image. (A histogram of an image is a graphical representation of the tonal distribution in a digital image. It contains what all the brightness values contained in an image are. It plots the number of pixels for each brightness value. It helps in doing the exposure settings.) from PIL import Image Python `
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
#Getting histogram of image
print img.histogram()
except IOError:
pass
if name == "main":
main()
`
- **Transposing an Image: This feature gives us the mirror image of an image Python `
from PIL import Image
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
#transposing image
transposed_img = img.transpose(Image.FLIP_LEFT_RIGHT)
#Save transposed image
transposed_img.save("transposed.jpg")
except IOError:
pass
if name == "main":
main()
` 
- **Split an image into individual bands: Splitting an image in RGB mode, creates three new images each containing a copy of the original individual bands. Python `
from PIL import Image
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
#splitting the image
print img.split()
except IOError:
pass
if name == "main":
main()
` 
- **tobitmap: Converting an image to an X11 bitmap (A plain text binary image format). It returns a string containing an X11 bitmap, it can only be used for mode “1” images, i.e. 1 bit pixel black and white images. from PIL import Image Python `
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
print img.mode
#converting image to bitmap
print img.tobitmap()
print type(img.tobitmap())
except IOError:
pass
if name == "main":
main()
` 
- **Creating a thumbnail: This method creates a thumbnail of the image that is opened. It does not return a new image object, it makes in-place modification to the currently opened image object itself. If you do not want to change the original image object, create a copy and then apply this method. This method also evaluates the appropriate to maintain the aspect ratio of the image according to the size passed. from PIL import Image Python `
def main():
try:
#Relative Path
img = Image.open("picture.jpg")
#In-place modification
img.thumbnail((200, 200))
img.save("thumb.jpg")
except IOError:
pass
if name == "main":
main()
`
