The vector graphic
is one of the basic methods of image data storage. It is based on a mathematic description of curves, colors and color fillings, ensuring high quality reproduction independent on dimension. In the vector graphic
the image consists of individual graphic elements (line, triangle, circle, filling, color gradients). For example charts, schemes, logos, etc. can be stored in vector form. The vector format is not suitable for storing photo images.
There are many vector graphic formats, but the most promising these days seems to be the SVG format, which is storing the data as a XML file.
is the abbreviation of Scalable Vector Graphics
. It is possible to edit the source code the same way as HTML
. The complete syntax of the SVG-XML
language can be found at http://www.w3.org/TR/SVG11/
The objects in SVG image are drawed subsequently by the order of creation. It can be grouped, formatted by means of the attributes or CSS styles and positioned using general space transformations.
SVG support in the PROMOTIC system
The PROMOTIC system uses the SVG
graphics in the PmaPanel
object (in objects PmgRasterImage
, as stream animation in the PmgPipe
It can be used a logically structured preset technological images
palette (in SVG
format) for graphic selection in the PROMOTIC system. The preset palette contains preview and description of each image. The preset images are divided into logical groups (e.g. boilers, engines, pumps, electronics, ...).
The full SVG format syntax is not supported
in the PROMOTIC system. Following SVG
features are not usable in the PROMOTIC system:
- raster images (raster images)
- text objects
- some tag (<desc>, <title>, <metadata> ...)
- some tag attributes (viewBox, stroke-dasharray, ...)
Simple SVG graphic projects can be created by means of the common notepad
. Some basic SVG syntax
knowledge is presumed. It is possible to get inspired by the preset images located in the \Promotic\PmVXXYY\Resource\Img
There are multiple SVG vector graphic editors available on the Internet. The commercial products are usually available as limited (demo) versions (Illustrator, Freehand, CorelDraw, or Xara X). As for non-commercial products you can find for example the Inkskape editor (http://www.inkscape.org), or svg-edit (http://code.google.com/p/svg-edit/), that can be used without installation directly in the Web browser.
Handy hints for SVG graphics creation:
- The PROMOTIC system includes some limitations that have to be considered while creating SVG graphics. It is useful to check the project by viewing it through the PmaPanel
object of the PROMOTIC system.
- The programs are usually processing the source syntax transformations when moving the graphic objects. It is useful to enable Optimalization in the Transformation, Save transformation: section of the Inkskape program. In another programs it is for example Apply transformation, ...
- Some programs keep the project semifinished when saved usually (signs, editing notes). When saving the final version of the project in Inkskape it is necessary to choose Plain SVG(*.svg) in the File/Save as ... section.
- The source code of images created in svg-edit is very well arranged. There are no needless transformations created when the position of the graphic objects is modified and the resulting image is correctly usable in the PROMOTIC system. This tool is recommended for creating SVG images for the PROMOTIC system.