The area of interest (AOI) feature allows you to specify a portion of the CMOS array and during operation, only the pixel information from the specified portion of the array is transmitted out of the camera.

The area of interest is referenced to the top left corner of the CMOS array. The top left corner is designated as column 0 and row 0.

The location and size of the area of interest is defined by declaring a left-most column, a width, a top row and a height. Reference position is the top left corner of the image. For example, suppose that you specify the left column as 10, the width as 16, the top row as 4 and the height as 10. The area of the array that is bounded by these settings.

The camera will only transmit pixel data from within the area defined by your settings. Information from the pixels outside of the area of interest is discarded.

The sum of the setting for Left plus the setting for Width must not exceed 659.
The sum of the setting for Top plus the setting for Height must not exceed 493.

Changes to the Frame Rate With AOI

In general, the maximum allowed frame rate for the camera increases as the size of the AOI decreases. However, the maximum allowed frame rate can also be limited by any one of three factors

• The amount of time it takes to transfer a captured image from the image sensor to the frame buffer.
• The amount of time it takes to transfer an image from the frame buffer to the PC via the IEEE 1394 bus.
• The exposure time setting.

To determine the maximum allowed frame rate for a given AOI, use your AOI and exposure time settings to calculate a result in each of the three formulas - refer to camera manual. These formulas take your AOI size into account plus the other factors that can limit the frame rate. The formula that returns the lowest value will determine the maximum allowed frame rate for the given AOI.