36.9 Image Bounding Box

Bounding boxes are often used to highlight specific regions within an image, such as a face. Here we use the MLHub package azcv to obtain the bounding box of a face and to then annotate the image appropriately.

$ wget -O img.jpg \
https://upload.wikimedia.org/wikipedia/commons/thumb/7/72/\
Laurence_Freeman11.JPG/800px-Laurence_Freeman11.JPG

$ ml faces azcv img.jpg 
263 205 529 471,Male,58

$ ml faces azcv img1.jpg | tee img1.bb
263 205 529 471,Male,58

$ cat img.bb |
  cut -d, -f1 |
  xargs printf '-draw "rectangle %s,%s %s,%s" ' |
  awk '{print "img.jpg -fill none -stroke blue -strokewidth 3 " $0 "img_faces.png"}' |
  xargs convert

$ display img_faces.png 

Using imagemagick to draw a bounding box onto an image. {#graphics:fig:imagemagick_bb}

The photo used here was taken by Eugenio Hansen, OFS, CC BY-SA 3.0.

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