Measurement data points – Adobe Photoshop CS4 User Manual
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610
USING PHOTOSHOP CS4
3D and technical imaging
Last updated 1/10/2010
3
(Optional) Choose Analysis > Select Data Points and do one of the following:
•
Choose Custom to select data points to measure.
•
Select an existing data point preset from the submenu.
For a video on understanding and using the measurement features, see
.
In the Select Data Points dialog box, data points are grouped according to the measurement tool that can measure
them. The Common data points are available for all tools. They add useful information to the Measurement Log such
as the name of the file being measured, the measurement scale, and the date/time of the measurement.
By default all data points are selected. You can select a subset of data points for a particular type of measurement, then
save the combination as a data point preset.
Note: When you measure with a particular tool, only the data points associated with that tool are displayed in the log,
even if other data points are selected. For example, if you make a measurement with the Ruler tool, only the Ruler tool
data points appear in the Measurement Log, along with any Common data points that are selected.
4
Choose an image feature and measurement tool to match the selected data points. Do one of the following:
•
Create one or more selections on the image.
•
Choose Analysis > Ruler Tool, or click the Ruler tool in the toolbox, then use the tool to measure the length of an
image area.
•
Choose Analysis > Count Tool, or click the Count tool in the toolbox, then count items in the image.
5
Choose Window
> Measurement Log to open the Measurement Log panel.
6
Choose Analysis > Record Measurements, or click Record Measurements in the Measurement Log panel.
Note: If your currently selected data points do not correspond to the current measurement tool, you are asked to select
data points for that tool.
The Measurement log has columns for each data point you selected in the Measurement Data Points dialog box. Each
measurement you make enters a new row of data in the Measurement Log.
If you measure multiple selected areas on the image, one row of data is created in the log containing summary or
cumulative data for all selected areas, followed by a row of data for each selection area. Each selection area is listed as
a separate Feature in the Label column of the log and assigned a unique number.
You can repeat steps 2 through 6 for a variety of different selections in the same or multiple documents. The Document
column in the Measurement Log reflects the source of the measurement data.
Measurement Data Points
Angle
Angle of orientation (±0-180) of the Ruler tool.
Area
Area of selection in square pixels, or in calibrated units according to the current measurement scale (such as
square millimeters).
Circularity
4pi(area/perimeter
2
). A value of 1.0 indicates a perfect circle. As the value approaches 0.0, it indicates an
increasingly elongated polygon. Values may not be valid for very small selections.
Count
Varies according to the measuring tool used. Selection tool: the number of discontiguous selection areas on the
image. Count tool: the number of counted items on the image. Ruler tool: the number of Ruler lines visible (1 or 2).
Date and Time
Applies a date/time stamp of when the measurement occurred.
Document
Identifies the document (file) measured.