worldfile

About Worldfile

A world file is a plain text file used to georeference raster map images. It describes the location, scale and rotation of the map.

The world file extension can be *.wld or must be respect one of these conventions:

Image extension	World file extension
tif	tfw / tfwx / tifw
jpg	jgw / jgwx / jpgw
bmp	bpw / bpwx / bmpw
png	pgw / pgwx / pngw

A worldfile has six-line with decimal numbers on each.

Line number	Parameter
1	pixel size in the x-direction in map units/pixel
2	rotation about y-axis
3	rotation about x-axis
4	pixel size in the y-direction in map units (always negative)
5	x-coordinate of the center of the upper left pixel
6	y-coordinate of the center of the upper left pixel