Convert file format

Convert file oldname to newname

proc convert {oldname newname} {
  set wand [magick create wand]
  $wand ReadImage $oldname
  $wand WriteImage $newname
  magick delete $wand
}

Call procedure

convert sample.png sample.jpg

Annotation

Load a png image, resize it and draw rotated text "MyrmecoX" over the image. Then save as the jpg, gif, and pdf files.

Load the tclMagick package

package require TclMagick

Create wand & draw objects

set wand [magick create wand]
set draw [magick create draw]

Load and resize a sample.png

$wand ReadImage sample.png
$wand ResizeImage 512 280 cubic

Draw a red "MyrmecoX" rotated by 45 degree

$draw push graph
  $draw SetStrokeWidth 1
  $draw SetStrokeColorString "red"
  $draw SetFillColorString "red"
  $draw SetFontSize 32
  $draw Annotation -97 170 "MyrmecoX"
$draw pop graph
$draw Rotate -45

$wand DrawImage $draw

Store the image in different file formats

foreach ext {jpg gif pdf} {
  $wand WriteImage sample.$.ext
}

Delete wand and draw objects

magick delete $draw
magick delete $wand