{"id":3870,"date":"2019-10-03T08:03:59","date_gmt":"2019-10-03T06:03:59","guid":{"rendered":"https:\/\/pythonprogramming.altervista.org\/?p=3870"},"modified":"2019-10-03T19:18:41","modified_gmt":"2019-10-03T17:18:41","slug":"a-brief-guide-to-pil-python-image-library","status":"publish","type":"post","link":"https:\/\/pythonprogramming.altervista.org\/a-brief-guide-to-pil-python-image-library\/","title":{"rendered":"A brief guide to PIL, python image library"},"content":{"rendered":"
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What is PIL<\/h3>\n<\/div>\n

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PIL<\/b> is a powerful module for Python<\/b> that allows you to create and elaborate images<\/b> by conding in Python. You can do almost anything, building the perfect image tools for your needs.We will take a fast look at the main functions of this very useful module.<\/p>\n<\/div>\n

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Install<\/h3>\n<\/div>\n

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First you need to install pil’s fork pillow:pip install pillow<\/p>\n<\/div>\n

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Import<\/h3>\n<\/div>\n

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The first thing you need to import is the Class Image
\n>>> from <\/b>PIL import <\/b>Image<\/p>\n<\/div>\n

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Create<\/h3>\n<\/div>\n

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>>> img = Image.new<\/b>(‘RBG’, (200,200), ‘yellow’)<\/p>\n

This will create<\/b> a yellow square image of 200 px of width<\/b> and 200 px of height.<\/b> RGB<\/b> is for Red, Green and Blue, aka the image is in color. If you want to use transparency<\/b> you have to use RGBA<\/b> instead of RGB.<\/p>\n<\/div>\n

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Open<\/h3>\n<\/div>\n

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>>> img = Image.open<\/b>(‘existing.png’)<\/p>\n<\/div>\n

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Save<\/h3>\n<\/div>\n

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>>> img.save<\/b>(‘myimage.png’)<\/p>\n<\/div>\n

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Show<\/h3>\n<\/div>\n

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>>> img.show<\/b>()<\/p>\n<\/div>\n

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Resize<\/h3>\n<\/div>\n

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>>> img.resize<\/b>((100,100), Image.ANTIALIAS)<\/p>\n<\/div>\n

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Filters for the images<\/h3>\n<\/div>\n

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>>> img.filter<\/b>(ImageFilter.BLUR)<\/p>\n

There’s a much smoother blur called SMOOTH
\n>>> i = i.filter<\/b>(ImageFilter.SMOOTH )<\/p>\n

You can then create a ‘contour’ effect
\n>>> i = i.filter<\/b>( ImageFilter.CONTOUR )<\/p>\n<\/div>\n

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Blend 2 images together<\/h3>\n<\/div>\n

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>>> img = Image.blend<\/b>(Image.open<\/b>(‘image1.png’,’image2.png’, 0.5) )<\/p>\n<\/div>\n

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Pasting an image on another<\/h3>\n<\/div>\n

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>>> img.paste<\/b>((0,0),’image2.png’)<\/p>\n<\/div>\n

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Write text on an image (ImageDraw)<\/h3>\n<\/div>\n

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>>> draw = ImageDraw.Draw<\/b>(img)
\n>>> draw.text<\/b>(0,0,’This <\/b>text goes on top of the image’)<\/p>\n<\/div>\n

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Thumbnail<\/h3>\n<\/div>\n

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>>> im.thumbnail<\/b>((128, 128), Image.ANTIALIAS)<\/p>\n<\/div>\n

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text and font<\/h3>\n<\/div>\n

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To add a text<\/b> to an image<\/b> after you created an image:
\n>>> im = img.new<\/b>(“RGBA”, (600,400), “yellow”)<\/p>\n

You create a ImageDraw<\/b>.Draw object to wich you pass the im<\/b> object you created and on wich you draw:
\n>>> d = ImageDraw.Draw<\/b>(im)<\/p>\n

Now you are ready to add a text to the d<\/b> object, but you can define the size<\/b> and family<\/b> of the text, using the ImageFont<\/b> class<\/b> (that you need to import from PIL) together with the method truetype:<\/b><\/p>\n


\n>>><\/b> font = ImageFont.truetype<\/b>(“Arial 20”)<\/p>\n

Now, you can finally add this font to the font<\/b> argument<\/b> when you add the text like this:<\/p>\n

>>> d.text<\/b>((10,10), “text to show”, (255,255,255), font=font)<\/p>\n