计算机图像基础

颜色和RGBA值

>>> from PIL import ImageColor >>> ImageColor.getcolor <function getcolor at 0x0000022E2FDE5598> >>> ImageColor.getcolor('red','RGBA') (255, 0, 0, 255) >>> ImageColor.getcolor('red','RGB') (255, 0, 0)

坐标和Box元组

用Pillow操作图像

>>> from PIL import Image >>> catIm = Image.open('zophie.png')

处理Image数据类型

>>> from PIL import Image >>> catIm = Image.open('zophie.png') >>> catIm <PIL.PngImagePlugin.PngImageFile image mode=RGB size=816x1088 at 0x22E2FDDDF28> >>> catIm.size (816, 1088) >>> catIm.width 816 >>> catIm.height 1088 >>> catIm.filename 'zophie.png' >>> catIm.format 'PNG' >>> catIm.format_description 'Portable network graphics' >>> catIm.save('zophie.jpg') from PIL import Image >>> im = Image.new('RGBA',(100,200),'purple') >>> im.save('purpleImage.png') >>> im2 = Image.new('RGB',(20,20)) >>> im2.save('transparentImage.png')

裁剪图片

>>> from PIL import Image >>> catIm = Image >>> catIm = Image.open('zophie.png') >>> cropedIm = catIm >>> cropedIm = catIm.crop((335,345,365,560)) >>> cropedIm.save('cropped.png')

复制和粘贴图像到其他图像

>>> catIm = Image.open('zophie.png') >>> catCopyIm = catIm.copy() >>> faceIm = catIm.crop((335,345,565,560)) >>> faceIm.size (230, 215) >>> catCopyIm.paste(faceIm,(0,0)) >>> catCopyIm.paste(faceIm,(400,500)) >>> catCopyIm.save('pasted.png') >>> catImWidth,catImHeight = catIm.size >>> faceImWidth,faceImHeight = faceIm.size >>> catCopyTwo = catIm.copy() >>> for left in range(0,catImWidth) SyntaxError: invalid syntax >>> for left in range(0,catImWidth,faceImWidth): for top in range(0,catImHeight,faceImHeight): print(left,top) catCopyTwo.paste(faceIm,(left,top)) 0 0 0 215 0 430 0 645 0 860 0 1075 230 0 230 215 230 430 230 645 230 860 230 1075 460 0 460 215 460 430 460 645 460 860 460 1075 690 0 690 215 690 430 690 645 690 860 690 1075 >>> catCopyTwo.save('tiled.png')

调整图像大小

>>> width,height = catIm.size >>> quartersizedIm = catIm.resize((int(width/2),int(height/2)),Image.ANTIALIAS) >>> quartersizedIm.save('quartersized.png') >>> svelteIm = catIm.resize((width,height+300),Image.ANTIALIAS) >>> svelteIm.save('svelte.png')

旋转和翻转图像

>>> catIm.rotate(90).save('rotated90.png') >>> catIm.rotate(180).save('rotated180.png') >>> catIm.rotate(270).save('rotated270.png') >>> catIm.rotate(6).save('rotated6.png') >>> catIm.rotate(6,expand=True).save('rotated6_expand.png')

>>>catIm.transpose(Image.FLIP_LEFT_RIGHT).save('horizontal_flip.png') #左右镜像翻转 >>> catIm.transpose(Image.FLIP_TOP_BOTTOM).save('vertical_flip.png') #上下镜像翻转

更改单个像素

>>> im = Image.new('RGBA',(100,100)) >>> im.getpixel((0,0)) (0, 0, 0, 0) >>> for x in range(100): for y in range(50): im.putpixel((x,y),(210,210,210)) >>> from PIL import ImageColor >>> for x in range(100): for y in range(50,100): im.putpixel((x,y),ImageColor.getcolor('darkgray','RGBA')) >>> im.getpixel((0,0)) (210, 210, 210, 255) >>> im.save('putPixel.png')

小实验——添加徽标

#! python3 #-*- encoding: utf-8 -*-# resizeAndAddLogo.py - # Usage: # # Author : qmeng # MailTo : qmeng1128@163.com # QQ : 1163306125 # Blog : http://blog.csdn.net/Mq_Go/ # Create : 2018-02-19 15:40:07 # Version: 1.0 # import os from PIL import Image SQUARE_FIT_SIZE = 300 LOGO_FILENAME = 'catlogo.png' #打开徽标图案 logoIm = Image.open(LOGO_FILENAME) logoWidth,logoHeight = logoIm.size #遍历所有文件打开图像 for filename in os.listdir('.'): if not (filename.endswith('.png') or filename.endswith('.jpg')) or filename == LOGO_FILENAME: continue im = Image.open(filename) width,height = im.size if width > SQUARE_FIT_SIZE and height > SQUARE_FIT_SIZE: if width > height: height = int((SQUARE_FIT_SIZE/width)*height) width = SQUARE_FIT_SIZE else: width = int((SQUARE_FIT_SIZE/height)*width) height = SQUARE_FIT_SIZE print('Resizing %s...'%(filename)) im.resize((width,height),Image.ANTIALIAS) print('Adding logo to %s...'%(filename)) im.paste(logoIm,(width - logoWidth,height - logoHeight),logoIm) im.save(os.path.join('withLogo',filename))

在图像上绘画

>>> from PIL import Image,ImageDraw >>> im = Image.new('RGBA',(200,200),'white') >>> draw = ImageDraw.Draw(im) >>>

绘制形状

点 线 矩形 多边形

>>> draw.line([(0,0),(199,0),(199,199),(0,199),(0,0)],fill='black') >>> draw.rectangle((20,30,60,60),fill='blue') >>> draw.ellipse((120,30,160,60),fill='red') >>> draw.polygon(((58,87),(79,62),(94,85),(120,90),(103,113)),fill='brown') >>> for i in range(100,200,10): draw.line([(i,0),(200,i-100)],fill='green') >>> im.save('drawing.png')

绘制文本

>>> im = Image.new('RGBA',(200,200),'purple') >>> draw = ImageDraw.Draw(im) >>> draw.text((20,150),'hello',fill='red') >>> fontsFolder = ImageFont.truetype('arial.ttf',32) >>> draw.text((100,150),'Howdy',fill='gray',font=fontsFolder) >>> im.save('text.png')