使用Python图像处理库Pillow处理图像文件的案例分析

>>> import PIL; from PIL import Image
>>> im = PIL.Image.open("c:/pythonpa/cs/img/mandrill.jpg")
>>> im.show()
>>> print(im.format, im.size, im.mode) #显示图像的格式、大小和模式信息
JPEG (298, 298) RGB

>>> im2 = PIL.Image.new('RGB', (800,600))

#模块：c:\pythonpa\cs\image_test.py
#命令行：python image_test.py c:\pythonpa\cs\img\mandrill.jpg
#功能：把c:\pythonpa\cs\img\mandrill.jpg的4个副本排列成2×2网格并显示
import sys
import os
import PIL.Image
import PIL.ImageFilter
im = PIL.Image.open(sys.argv[1])
width, height = im.size
# 创建新图像，大小为原始图像的4倍
res = PIL.Image.new(im.mode, (2*width, 2*height))
# 把原始图像放置在左上角
res.paste(im, (0, 0, width, height))
# 把轮廓过滤CONTOUR的图像放置在右上角
contour = im.filter(PIL.ImageFilter.CONTOUR)
res.paste(contour, (width, 0, 2*width, height))
# 把浮雕过滤EMBOSS的图像放置在左下角
emboss = im.filter(PIL.ImageFilter.EMBOSS)
res.paste(emboss, (0, height, width, 2*height))
# 把边缘过滤FIND_EDGES的图像放置在右下角
edges = im.filter(PIL.ImageFilter.FIND_EDGES)
res.paste(edges, (width, height, 2*width, 2*height))
# 显示结果图像
res.show()

#模块：c:\pythonpa\cs\image_convert.py
#命令行：python image_convert.py c:\pythonpa\cs\img jpg png
#功能：把c:\pythonpa\cs\img下的所有jpg文件转换为png文件
import sys
import glob
import os
import PIL.Image
img_path = sys.argv[1] + "/*." + sys.argv[2]
for infile in glob.glob(img_path):
    f,e = os.path.splitext(infile)
    outfile = f + "." + sys.argv[3]
    PIL.Image.open(infile).save(outfile)

#模块：c:\pythonpa\cs\ image_thumbnail.py
#命令行：python image_thumbnail.py c:\pythonpa\cs\img jpg
#功能：把c:\pythonpa\cs\img下的所有*.jpg文件转换为*_s.jpg缩略图
import sys
import os
import glob
import PIL.Image
img_path = sys.argv[1] + "/*." + sys.argv[2]
size = (128,128)
for infile in glob.glob(img_path):
    f,e = os.path.splitext(infile)
    outfile = f + "_s." + sys.argv[2]
    img = PIL.Image.open(infile)
    img.thumbnail(size, PIL.Image.ANTIALIAS)
    img.save(outfile)

#模块：c:\pythonpa\cs\image_watermark1.py
#命令行：python image_watermark1.py c:\pythonpa\cs\img jpg "Python"
#功能：把c:\pythonpa\cs\img下的所有*.jpg文件加"Python"水印并另存为*_w.jpg
import sys
import os
import glob
from PIL import Image, ImageDraw, ImageFont
img_path = sys.argv[1] + "/*." + sys.argv[2]
img_suffix = sys.argv[2]
txt_log = sys.argv[3]
for infile in glob.glob(img_path):
    f, e = os.path.splitext(infile)
    outfile = f + "_w." + img_suffix
    im = Image.open(infile)
    im_log = Image.new('RGBA', im.size)
    fnt = ImageFont.truetype("c:/Windows/fonts/Tahoma.ttf", 20)
    d = ImageDraw.ImageDraw(im_log)
    d.text((0, 0), txt_log, font = fnt)
    im_out = Image.composite(im_log, im, im_log)
    im_out.save(outfile)

#模块：c:\pythonpa\cs\image_watermark2.py
#命令行：python image_watermark2.py c:\pythonpa\cs\img jpg c:\pythonpa\cs\img\python-logo.png
#功能：把c:\pythonpa\cs\img下的所有*.jpg文件加水印python-logo.png并另存为*_w.jpg
import sys
import os
import glob
from PIL import Image, ImageDraw, ImageFont
img_path = sys.argv[1] + "/*." + sys.argv[2]
img_suffix = sys.argv[2]
log_file = sys.argv[3]
for infile in glob.glob(img_path):
    f, e = os.path.splitext(infile)
    outfile = f + "_w." + img_suffix
    im = Image.open(infile)
    im_log = Image.open(log_file)
    im_mark = Image.new('RGBA', im.size)
    im_mark.paste(im_log, (0, 0))
    im_out = Image.composite(im_mark, im, im_mark)
    im_out.save(outfile)

#模块：c:\pythonpa\cs\image_resize.py
#命令行：python image_resize.py c:\pythonpa\cs\img jpg 640 480
#功能：把c:\pythonpa\cs\img下的所有*.jpg文件大小调整为640*480并另存为*_640.jpg
import sys
import os
import glob
import PIL.Image
img_path = sys.argv[1] + "/*." + sys.argv[2]
img_suffix = sys.argv[2]
img_size_width = int(sys.argv[3])
img_size_height = int(sys.argv[4])
for infile in glob.glob(img_path):
    f, e = os.path.splitext(infile)
    outfile = f + "_" + str(img_size_width) + "." + img_suffix
    im = PIL.Image.open(infile)
    im_out = im.resize((img_size_width, img_size_height))
    im_out.save(outfile)