Questions

Will Engauge work on my computer?

Hardware requirements are described on the Requirements page, and links to pre-built binary releases are available on the Platforms page. Source code releases may be installed on unsupported computers, but this process is quite time consuming and sometimes confusing.

What types of image files can be used?

Files with the following extensions are recognized: bmp, gif, jpg, png, pnm, and xpm.

How can I create an image that shows a graph or map?

Scanners and digital cameras can capture a graphs or map on paper, and create an image file that can be imported into Engauge Digitizer.

If the graph or map is on your computer screen, just take a screenshot. In Microsoft Windows, use the PrintScreen button to capture the screenshot, and then use a graphics program like MS Paint to copy the screenshot in the clipboard into a BMP file. In Linux, use a screenshot tool like ScreenShooter or ksnapshot.

What distortions can be effectively removed from graphs?

Engauge Digitizer compensates for rotation, scaling and skew (also known as shearing) in graphs. In math terms, Engauge Digitizer performs an affine transformation to compensate for these effects.

No compensation is performed for the keyhole effect, which can arise from misalignment of a digital camera.

No compensation is performed for maps per se, since there is not enough information. However, if a map is imported and then treated like a graph (meaning three points and their coordinates are entered), then an affine transformation will be used to remove skew.

How accurate are the numbers produced by Engauge Digitizer?

Assuming there are no significant distortions, the numeric resolution is only as good as the pixel resolution of the original image. The resolutions in the horizontal and vertical directions are displayed in the bottom right corner of the status bar once the coordinates are defined.