Python Learning Notes (42) third-party module (PIL) image processing

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Installing Pillow

Install directly from the PIP at the command line:

$ pip Install Pillow

If you encounter an Permission denied installation failure, add a sudo retry.

manipulating Images

To see the most common image scaling operations, just three or four lines of code:

 fromPILImportImage#open a JPG image file, note the current path:im = Image.open ('test.jpg')#Get image size:W, h =im.sizePrint('Original image size:%sx%s'%(W, h))#Zoom to 50%:Im.thumbnail (W//2, H//2))Print('Resize image to:%sx%s'% (W//2, H//2))#Save the scaled image in JPEG format:Im.save ('thumbnail.jpg','JPEG')

Other features such as slicing, rotating, filters, output text, color palettes, and more.

For example, the blur effect also requires just a few lines of code:

 from Import Image, ImageFilter # open a JPG image file, note that the current path is im = Image.open ('test1.jpg')#  Apply Blur filter:im2 = im.filter (imagefilter.blur) im2.save ('blur.jpg' ' JPEG ')

Effect:

PiL ImageDraw provides a series of drawing methods so that we can draw directly. For example, to generate a letter Captcha image:

 fromPILImportImage, Imagedraw, Imagefont, ImageFilterImportRandom#Random Letters:defRndchar ():returnChr (Random.randint (65, 90))#random color 1:defRndcolor ():return(Random.randint (255), Random.randint (255), Random.randint (64, 255))#Random color 2:defRndColor2 ():return(Random.randint (127), Random.randint (127), Random.randint (32, 127))#x:width = 60 * 4Height= 60Image= Image.new ('RGB', (width, height), (255, 255, 255))#To Create a Font object:Font = Imagefont.truetype ('Arial.ttf', 36)#To create a draw object:Draw =Imagedraw.draw (image)#fill each pixel: forXinchRange (width): forYinchRange (height): Draw.point ((x, y), fill=Rndcolor ())#Output Text: forTinchRange (4): Draw.text ((* t + ten, Rndchar (), Font=font, fill=RndColor2 ())#Blur:Image =Image.filter (Imagefilter.blur) Image.Save ('code.jpg','JPEG')

We fill the background with random color, then draw the text, and finally blur the image, get the captcha image as follows:

If you run an error:

IOError: cannot open resource

This is because PiL cannot navigate to the location of the font file and can provide an absolute path based on the operating system, such as:

' C:/windows/winsxs/amd64_microsoft-windows-font /arial.ttf '

To learn more about the powerful features of PiL, please refer to the Pillow official documentation:

https://pillow.readthedocs.org/

Summary

PIL provides a powerful function of manipulating images, which can be done with simple code to complete complex image processing.

Python Learning Notes (42) third-party module (PIL) image processing