require 'RMagick'
include Magick
images = ImageList.new("sf.jpg")
images.alpha = ActivateAlphaChannel
dr = Draw.new
dr.fill = "#00000050"
dr.roundrectangle(40,50, 160,80, 10,10)
dr.polygon(*[100,81, 100,91, 110,81])
dr.draw(images);
# フォント
dr.font = "Tahoma"
# ポイントサイズ
dr.pointsize = 15
# 描画色
dr.fill = "#ffffffd0"
# gravity
dr.gravity = CenterGravity
dr.annotate(images, 0, 0, 55, 55, "San Francisco"){
self.gravity = NorthWestGravity
}
images.write("sample915a.png")
exit
元画像(sf.jpg)
出力画像(sample915a.png)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0MHwyU_fihOI4t6GX7I7nu1j5OJomOtAU2fsD_lXVxyYE4dBe0_hVvi3JfGDzeNR2XElE8NT-t5zZ-q3nyfAMpy_i1qyQYmVYZ4k5NAeCsPJ-7w3lzOQn2n1qoP9Xxctmr9HF/s320/sample915a.png)
動作環境
ruby1.8.6, rmagick2.7.1