diff --git a/shell.rb b/shell.rb
new file mode 100644
index 0000000..595884b
--- /dev/null
+++ b/shell.rb
@@ -0,0 +1,22 @@
+# array for base filenames
+base_names = []
+
+# change into image directory
+Dir.chdir("image_batch")
+
+# collect all base filenames
+Dir["*.png"].map{|file| base_names << file.split('.').first}
+
+# using system call
+# 'magick' here is a version 7+ option, previous versions would be just 'convert'
+base_names.map {|file| system("magick convert #{file}.png #{file}.jpg")}
+
+# option: using mini_magick
+#base_names.each do |file|
+  #image = MiniMagick::Image.open("#{file}")
+  #image.format "jpg"
+  #image.write("#{file.split('.').first}.jpg")
+#end
+
+# list all of the files in the image directory
+Dir["*"].map{|file| puts file}