A second example of using the external module

Heres another example of the external module.

In this example, an image is imported/read in and composited on top of a color card and the result is fed to an external module like so.


The external module, once again, invokes the ImageMagick tool called convert to do its bidding.


In this example the -annotate instruction and a handful of option settings are used to have ImageMagick create simple text. The -font option specifies a true-type font file (a .ttf file), or a built-in font to use; -pointsize specifies the font size; -fill specifies the color that the ink-lines should be. The numbers with the pluses instruct ImageMagick how many pixels to the right and down from the top-left corner that the text should begin appearing.

(there is a harmless typo above–slash)

For this example I’m using a TTF file I downloaded and the web color called steelblue

This command generates text and it is superimposed with a composite module:


But to be able to independently move the text without moving the imported image a different set-up is used.


In this set-up an Apply-Image-Transformation module is hooked directly below. It receives the resulting text image from the external module and in conjunction with an attach peg, the text image can be transformed to a different location, size, and rotation. Because the external module is not a real-time operation that shows up in the OpenGL preview mode in the camera, a field-guide module is attached (but any similar guide would do)

The font is changed and the text is displaced and resized.