11.31 image

image [ item <id> ] <filename> [ at <vector> ]
         [ rotate <angle> ] [ width <length> ]
         [ height <length>] [ smooth ]
         [ notransparent ] [ transparent rgb <r>:<g>:<b> ]

The image command allows graphical images to be inserted onto the current multiplot canvas from files on disk. Input graphical images may be in bitmap, gif, jpeg or png formats; the file type of each image is automatically detected. The at modifier can be used to specify where the image should be placed on the vector graphics canvas; if it is not, then the image is placed at the origin. The settings texthalign and textvalign determined how the image is aligned relatively to this reference point – for example, whether its bottom left corner or its center is placed at the reference point.

The rotate modifier can be used to rotate images by any angle, measured in degrees counter-clockwise. The width or height modifiers can be used to specify the width or height with which images should be rendered; both should be specified in centimeters. If neither is specified then images are rendered with the native dimensions specified within the metadata present in the image file (if any). If both are specified, then the aspect ratio of the image is changed.

The keyword smooth may optionally be supplied to cause the pixels of images to be interpolated¹. Images which include transparency are supported. The optional keyword notransparent may be supplied to cause transparent regions to be filled with the image’s default background color. Alternatively, an RGB color may be specified in the form rgb<r>:<g>:<b> after the keyword transparent to cause that particular color to become transparent; the three components of the RGB color should be in the range 0 to 255.

All vector graphics objects placed on multiplot canvases receive unique identification numbers which count sequentially from one, and which may be listed using the list command. By reference to these numbers, they can be deleted and subsequently restored with the delete and undelete commands respectively.

Footnotes

1. Many commonly-used PostScript display engines, including Ghostscript, do not support this functionality.