# coding=UTF-8
import Image
# 画像を暗くする
img1 = Image.open("sf.jpg")
img2 = Image.new("RGB", img1.size, (0x00, 0x00, 0x00))
img3 = Image.blend(img1, img2, 0.5)
img3.save("sample628a.jpg")
元画像(sf.jpg)
出力画像(sample628a.jpg)

関連情報
Python Imaging Libraryまとめ

<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="200" height="200">
<defs>
<filter id="plf">
<feSpecularLighting in="SourceGraphic" result="lr" specularExponent="20" lighting-color="#ffffff">
<fePointLight x="70" y="70" z="30"/>
</feSpecularLighting>
<feSpecularLighting in="SourceGraphic" result="l2r" specularExponent="15" lighting-color="#aaccff">
<fePointLight x="180" y="170" z="25"/>
</feSpecularLighting>
<feComposite in="SourceGraphic" in2="lr" result="t1" operator = "arithmetic" k1 = "0" k2 = "1" k3 = "0.5" k4 = "0"/>
<feComposite in="t1" in2="l2r" operator = "arithmetic" k1 = "0" k2 = "1" k3 = "1" k4 = "0"/>
</filter>
</defs>
<g filter="url(#gbf)">
<image x="0" y="0" width="200px" height="200px"
xlink:href="sf.jpg" filter="url(#plf)">
<title>sf.jpg</title>
</image>
</g>
</svg>


<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="220" height="220">
<defs>
<filter id="gbf" filterUnits="userSpaceOnUse" x="0" y="0" width="220" height="50" >
<feGaussianBlur in="SourceAlpha" stdDeviation="4" result="shadow"/>
<feOffset in="shadow" dx="4" dy="4" result="shadow2"/>
<feComposite in="SourceGraphic" in2="shadow2" operator="over"/>
</filter>
</defs>
<image x="20" y="20" width="200" height="200"
xlink:href="sf.jpg" >
<title>sf.jpg</title>
</image>
<text x="10" y="30" font-family="Arial" font-size="30"
style="fill:#fffff8; stroke:#fffff8;" filter="url(#gbf)">San Francisco
</text>
</svg>

<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="300" height="300">
<defs>
<mask id="mask1" maskUnits="userSpaceOnUse"
x="0" y="0" width="300" height="300">
<rect x="50" y="50" width="200" height="200"
rx="20" ry="20"
style="fill:#ffffff; "/>
</mask>
<filter id="gbf">
<feGaussianBlur in="SourceAlpha" stdDeviation="4" result="shadow"/>
<feOffset in="shadow" dx="4" dy="4" result="shadow2"/>
<feComposite in="SourceGraphic" in2="shadow2" operator="over"/>
</filter>
</defs>
<g filter="url(#gbf)">
<image x="50" y="50" width="200px" height="200px"
xlink:href="sf.jpg" mask="url(#mask1)" >
<title>sf.jpg</title>
</image>
</g>
<!--mask="url(#mask1)" -->
</svg>








<?xml version="1.0"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink"
width="300" height="300">
<image x="50" y="50" width="200px" height="200px"
xlink:href="sf.jpg" transform="rotate(30,150,150)">
<title>sf.jpg</title>
</image>
</svg>






