Ever needed to generate simple test images with specific labels and different sizes? My specific use case involved creating the images and verify that they were being correctly delivered as ads in mobile apps. ImageMagick and Bash to the rescue!

generate_images_for.sh

# Usage: generate_image name widthxheight
# Example: generate_image desktop 1024x768
generate_image() {
	type=$1
	size=$2
	fname=ad_"$type"_"$size".png

	echo $fname;
	convert -size $size -font Bookman-Light -gravity center label:"VEJA.com 2.0\n$type\n$size" $fname
}

# Usage: generate_images name (widthxheight)*
# Example: generate_images xga 640x480 800x600 1024x768 
generate_images() {
	type=$1
	shift 1
	sizes=$@

	for size in $sizes; do 
		generate_image $type $size;
	done
}

AD_SPLASH="splash 320x480"
AD_HOME="home 137x57 320x50 320x480 320x66 320x187"

# This will take every environment variable with an AD_ prefix and use its value as a parameter for generate_images
for ad_var_name in  ${!AD_*}; do 
  ad_variable=$ad_var_name; 
  generate_images ${!ad_variable};
done