> For the complete documentation index, see [llms.txt](https://astra-image.gitbook.io/astra-image-6.0/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://astra-image.gitbook.io/astra-image-6.0/statistics-and-measurement/measurement-and-analysis.md).
# Measurement and Analysis
Measure once, analyze twice.
The Measurement and Analysis tool used to measure and straighten images. On the toolbar there are some important icons:
Region, line, measure buttons.
In this image, the first icon is selected, which is the Region tool. The next icon is the line tool. Rather than drawing a region (box, or region of interest), this will draw a line on the image. The right-most icon will display the Measurement and Analysis tool window.
The Measurement and Analysis window.
**Region**\
The four edit boxes contain the coordinates of the currently selection region (region of interest). The width, height and aspect ratio (A/R) of the region are also displayed.
**Line**\
When a line is drawn on the image, the length and logical length are calculated. In addition, the angle of the line and length in pixels are also displayed.
When a line is defined, you can click this button to straighten the image based on the angle of the line.
Click this button to change the color of the line.
**Example**
As an example, image that you know that 1 pixel in your image is equivalent to 2mm. You can set the measurement to 'mm' and the Logical length to 2.000. Then, as you draw a line on the image, you can see the measurement in mm. In the example below, the Length (pixels) is 75.0, and therefore our measurement is 150.00mm.
