Obtaining the pixel size from an image

A pixel size can be specified manually or it can be obtained from an image that contains an object of known size. In the latter case, after selecting an image file, the dialog box shown in Figure 1 appears.

Figure 1: Obtaining the pixel size from an image.

In order to compute the pixel size, delimit a segment in the image and specify its length in the unit of measure selected. From this data, BioVis3D can determine the pixel size by measuring the segment in pixels and comparing it with the specified segment length.

Begin by selecting a unit of measure and setting the field Segment Length with the length of the segment to measure. Once this information is entered, click once at the starting point of the segment, and then click at the end. After the first click and before the second click, a black segment is drawn while the mouse is moved (see Figure 1) to show in the screen the segment being measured.

Note that the segment length is mandatory to compute the pixel size. If the image is clicked while this field is empty, a message requesting a valid segment length, will appear.

Once the segment is delimited, the pixel size is computed and shown in the field Resulting Pixel Size.

To confirm and close the dialog box, click Ok .