Overview of Raster Images
 
 
 

Raster images consist of a rectangular grid of small squares or dots known as pixels. For example, a photograph of a house is made up of a series of pixels colorized to represent the appearance of a house. A raster image references the pixels in a specific grid.

Raster images, like many other drawing objects, can be copied, moved, or clipped. You can modify an image with grip modes, adjust an image for contrast, clip the image with a rectangle or polygon, or use an image as a cutting edge for a trim.

The image file formats supported by the program include the most common formats used in major technical imaging application areas: computer graphics, document management, engineering, mapping, and geographic information systems (GIS). Images can be bitonal, 8-bit gray, 8-bit color, or 24-bit color. Images with 16-bit color depth are not supported starting with AutoCAD 2010.

Several image file formats support images with transparent pixels. When image transparency is set to on, the program recognizes those transparent pixels and allows graphics in the drawing area to “show through” those pixels. (In bitonal images, background pixels are treated as transparent.) Transparent images can be gray-scale or color.

NoteAlthough the file name extension is listed in the following table, the file format is determined from the file contents, not from the file extension.

Use the Ribbon Contextual Tab to Work with Raster Images

If you select an image when the ribbon is active, the Image Ribbon Contextual tab displays. The contextual tab contains options for adjusting, clipping and displaying images. The ribbon contextual tab is dismissed automatically after the image is deselected.

Supported image file formats

Type

Description and versions

File extension

BMP

Windows and OS/2 bitmap format

.bmp, .dib, .rle

CALS-I

Mil-R-Raster I

.gp4, .mil, .rst, .cg4, .cal

FLIC

FLIC Autodesk Animator Animation

.flc, .fli

GeoSPOT

GeoSPOT (BIL files must be accompanied with HDR and PAL files with correlation data, in the same directory)

.bil

IG4

Image Systems Group 4

.ig4

JFIF or JPEG

Joint Photographics Expert Group

.jpg or .jpeg

PCX

Picture PC Paintbrush Picture

.pcx

PICT

Picture Macintosh Picture

.pct

PNG

Portable Network Graphic

.png

RLC

Run-Length Compressed

.rlc

TARGA

True Vision Raster-Based Data Format

.tga

TIFF

Tagged Image File Format

.tif or .tiff

Commands