About Vector and Raster Formats

Many vector and raster formats are supported but there is a specific behavior for the stroke properties. Note that the PostScript interpreter cannot load files exported from external softwares (such as Adobe Illustrator).

This page discusses:

See Also
In the Knowledge Base
Why do whitish lines appear in PDF files?

Vector

Vector files contain geometrical descriptions of the image elements. These elements may be lines, dots, rectangles, circles, polygons, splines, text with font information or bitmaps (only in metafiles) and are used to reconstruct the final image. Each element has its own attributes specifying its size, its relative position in the whole image, its color and filling type.

The following vector graphics formats are supported by some specific import functionality (such as Add > Import > CATIA File):

  • Windows Metafile (Windows only)
  • CGM The following CGM vector formats are supported:
    • CGM
    • CGM CALS
    • CGM ATA
    • CGM Graphic Software.

    CGM (Computer Graphics Metafile) is an ANSI/ISO standardized platform-independent format used for the interchange of vector and bitmap content. The CGM Version 1 and Version 3 standards are supported. CGM Version 3 adds vector primitives such as Bezier and Nurbs, improved font and text support as well as bitmap compression. The CGM-ATA and CGM-CALS profiles which are specific subsets of the Version 3 standard are also supported. For detailed information about CGM formats, browse the following website: http://www.cgmopen.org

  • PS (PostScript) PostScript is a page description language that supports text, vector graphics and bitmaps. It is device-independent and implements an industry standard for communicating graphic information between applications and hardware devices such as printers. For detailed information about PostScript, browse the following website: http://partners.adobe.com/asn/developer/pdfs/tn/PLRM.pdf
  • HPGL/HPGL2 (Hewlett-Packard Graphics Language) This file format is an instruction set developed for controlling plotters. HP-GL, which has been developed for pen plotters, is now obsolete. HP-GL/2-RTL is an evolution of HP-GL providing more graphic primitives (such as polygons or curves) and a support for bitmaps.
  • SVG (Scalable Vector Graphics) This format is an XML grammar for 2D graphics which means that SVG files can be created and edited with any text editor. Using this file format to design handles for 2D objects allows more flexibility because you can modify the graphic representation independently from the code. You can load SVG files containing graphics elements defined with gradients, transparency and stroke properties. You can use any appropriate graphics editor such as Inkscape to graphically edit SVG files.

The advantage of vector files over bitmap files is that image scaling does not affect image appearance. When zooming bitmap files, pixels become visible as shown in the example below:

Vector imageBitmap image




The table below summarizes the purposes of the above mentioned formats:

Purpose Printing/PlottingContent Exchange
Format
HPGL/2-RTLYesNo
PSYesNo
EPSNoYes
PDFNoYes
CGMNoYes
Important: High quality images require longer computation time.

Raster

Raster format is a bitmap image format generating images made up of pixels arranged in lines and columns (this grid of pixels being referred to as a bitmap). Some raster graphics formats are supported by specific applicative import functions (such as Add > Import > CATIA File).

  • Adobe Photoshop Format (*.psd)
  • Apple Macintosh File Format (*.pic)
  • Amiga IFF (*.iff)
  • CALS Group 4 (*.cals)
  • HP/RTL (UNIX only)
  • JPEG Fair Quality (*.jpg)
  • JPEG Medium Quality (*.jpg)
  • JPEG High Quality (*.jpg)
  • PNG (Portable Network Graphics) (*.png)
  • Silicon Graphics File (*.rgb)
  • Sun Raster File (*.ras)
  • TIFF CCITT Group 4 (*.tif)
  • TIFF True Color (*.tif)
  • TIFF Indexed Packbit (*.tif)
  • TIFF True Color Packbit (*.tif)
  • TIFF Indexed (*.tif)
  • TIFF Grey Scale Packbit (*.tif)
  • TIFF BW Packbit (*.tif)
  • Truevision Targa (*.tga)
  • RGB (SGI Format) Not Compressed (*.rgb)
  • ZSoft Paintbrush (*.pcx)
  • Windows Bitmap (*.bmp)
  • X-Window Pixmap (*.xpm)
  • X-Window Dump (*.xwd).

For detailed information about JPG and TIFF format, browse the following websites:

http://www.jpeg.org and http://www.ijg.org

http://partners.adobe.com/asn/developer/pdfs/tn/TIFFphotoshop.pdf

A bitmap image is fully described by its width and height, color depth (bits per pixel) and compression scheme. The common format is true color (24 bits per pixel). An additional color component, called Alpha component, may be used to define the transparency of each pixel.

The bitmap format generally supports compression (either lossless or lossy). Some of these bitmaps are coded on 8 bits and the pixels are indexed on a color table, called the palette. The advantage of bitmap files is that they can reproduce complex scenes (for example, photographic or photo-realistic images) that could not be reproduced using basic geometrical shapes.

The following table summarizes information about bitmap files and the various formats you can use to save images in the album ("x" means that the format is authorized):

Bit DepthCompressionMax. Size in PixelsComments
18162432NoneRLEJPEGZLIBCCITT
BMPxxxxxxx2G*2GStandard bitmap storage on MS-Windows.
JPEGxxxx64K*64KVery few applications support the lossless JPEG mode.
PNGxxxxxx2G*2GSuccessor of the GIF format.
RGBxxxxxxx64K*64Supported by very few applications.
TIFFxxxxxxxx2G*2GVery popular and general format recognized by most imaging applications.
Note: 2D textured polygons are correctly drawn when saved or printed in CGM, PS, PDF or SVG format. However, when using a Microsoft driver to print 2D textured polygons, the result depends on the driver's ability to deal with the transparency in bitmap images. For example, in HPGL2 format, textured polygons are partially saved because of a restriction regarding areas outside the polygon's boundaries that might hide nearby entities. As HPGL format does not support images, polygons are thus saved without any texture.

When printing an image, the image needs a large continuous block of memory. The following recommendations might help you when printing, capturing or exporting (through Save As) bitmap images with a large pixel width and/or height:

  • Whenever possible, use a vector image to describe vector geometries (you can insert vector images in a drawing)
  • Use a 64-bit computer (which has a larger memory allocation)
  • Whenever possible, convert the image to Grayscale or Black and White (for example TIFF with CCITT G3 encoding) before inserting it. This reduces the memory needed.

Raster 3DS Virtual Printer

The behavior of a Raster 3DS virtual printer is the same as a graphics card's behavior you can see on screen in a session.

The Raster 3DS virtual printer is very basic regarding line ends: if the line angle is below 45 degrees, the line end is vertical, otherwise it is horizontal. This printer does not support perpendicular line ends, or options such as Round, Square or Flat available in the Various tab of the Options dialog box. For example, when saving a drawing representation in TIFF format (through Share > Export), the line end is not perpendicular to the line direction as this is the case when printing on a Windows printer.

A Windows plotter driver is often more precise regarding line ends.



However, if you need to use a 3DS virtual printer, you can save your file in PDF format. This way, you use a 3DS virtual PDF printer and the generated file opens in Acrobat Reader.

HPGL2/RTL

Not all HPGL2/RTL orders are supported for raster images.

Below is the list of the supported HPGL2/RTL orders:

Escape SequenceCommand Name
Esc*r#sRaster width
Esc*r#tRaster height
Esc*b#mCompression mode
Esc*t#hDestination raster width
Esc*t#vDestination raster height
Esc*t#rGraphic resolution
Esc*v#wCustomize images
Esc*b#wContent by row/block

Stroke Properties

There is a specific behavior regarding the thickness, linejoin and linecap.

Thickness

Line thickness indexes are defined through a table (see Me > Preferences > General > Display > Thickness & Font). Each thickness index has a mm and pixel definition. The thickness information stored in the document is a length (for example 2.5 mm).

When importing or opening a vector graphics document with a stroke of "x" mm, a stroke is created with a thickness index whose mm definition is "x". If no index has a mm equal to "x", then the index with the closest mm definition is chosen. You might enrich the standards to ensure a better match.

When displayed on screen, the stroke thickness is independent of the zoom factor: it has a fixed thickness defined in pixels (the pixel definition of its thickness index).

As an example, let's consider a SVG file with a 10 mm diameter radius and a 2.7 mm thickness:

  • If you import this SVG in a drawing representation, the circle created has a thickness index 8 (2.6 mm is the closest thickness to 2.7 mm).
  • However, when displayed on screen, the circle is 8 pixels thick, whatever the zoom level.
SVG fileDrawing representation with imported SVG file




Circle thickness properties


Linejoin, Linecap

A vector graphics document might contains polylines with linejoin and linecap properties. However, the stroke has no such properties. Therefore, when importing or opening a vector graphics format document containing a polyline with a linejoin or linecap property, the resulting polyline is displayed without any consideration of this property:

SVG Linejoin PropertiesSVG Linecap PropertiesDisplayed Polyline






"Miter" join"Round" cap


"Round" join