A Manual for Giv
Dov Grobgeld
dov@imagic.weizmann.ac.il
Last modified: 2001-03-04

1. Name

giv - The G(reat|tk|NU) Image Viewer

2. Syntax

    giv {options} img
  

3. Description

giv is an image viewer with the following advantages:

• Based on the gtk_image_viewer widget.
• It doesn't suffer from the commercial restrictions of xv.
• It can display marks on top of an image.
• It can display monochrome components of a color image.
• In the future it should show histograms on top of images.
• It is especially suited for computational geometry and vision scientific and educational applications.

3.1. Images

Images are loaded through gdk_pixbuf and giv supports all the formats supported by it. The image may be scrolled and zoomed with the mouse or the keyboard.

Here is an example of the image display:

Normal scale	Zoom in

3.2. Marks

giv has the cabability to read marks files describing annotations that are drawn on top of the image. The annotations are loaded in marks files. The marks files contains one or more data sets. The data sets consist of properties, followed by the list of data points.

The properties all start with the $ sign. Here is a list of the properties supported:

Property	Example	Description
$color	$color pink3	The color of the data set
$marks	$marks	Indicates that the no lines should be drawn for the data set.
$marks	$marks circle	The type of the mark. Valid marks are: circle square
$scale_marks	$scale_marks	Indicates whether the marks should be scaled together with the image. Default is not to scale.
$noline	$noline	Don't draw line between the coordinates.
$mark_size	$mark_size 15	Specify the size of the marks in pixels.
$line	$line	Draw a line between the marks. This is needed if the noline has been choosen on the command line.
$lw	$lw 3	Line width.

3.3. Mark example

example.marks
1: $LW 3 2: $NOLINE 3: $MARKS circle 4: $SCALE_MARKS 1 5: $COLOR midnightblue 6: 110 110 7: 120 110 8: 120 120 9: 110 120 10: 110 110 11: 12: $MARKS square 13: $MARK_SIZE 12 14: $LW 5 15: $SCALE_MARKS 0 16: 120 120 17: 150 150 18: 120 150 19: 120 120 20: 21: 120 220 22: 150 250 23: move 120 250 24: 120 220 25: 26: $LW 5 27: 300 130 28: 300 180

Marks at default zoom	Marks zoomed in by 4

Note: The example above contains just a few points. Giv very easily supports several hundred thousand points. The only limitations is the physical memory and the speed of the CPU.

4. Command line options

Option	Description
-marks markfile	Specify a marks file.
-nl	Don't draw lines by default.
-ms ms	Specify default mark size.
-sm	Marks should scale by default.
-P	Draw marks by default.
-lw lw	Default line width.
-expand e	Initial expansion.

5. Interaction

Option	Description
q	Quit
= Ctrl-B1	Zoom in
- Ctrl-B3	Zoom out
t	Shrink wrap
h	Histogram equalization
n	Normal view.
N	Normalize histogram.
r	Reset histogram
B3	Popup options menu.