Sharpness

Supported by ...

All PL-B cameras except the PL-B781/2 and PL-B777/8 cameras.  Sharpness can be added to the PL-B781/PL-B782 and PL-B777/PL-B778 cameras if another feature is removed.  Contact Pixelink Sales for more information.

Description

The Sharpness feature is a standard convolution filter applied to the intensity (luma) channel as

where  is the Laplacian of the pixel luma at location (i,j). The Laplacian is implemented as a 3X3 convolution kernel filter as follows.

In the equation,  is a scaling factor applied to the original pixel value which, in the sharpness filter, is set to one.  is a scaling factor applied to the result of the laplacian.

It is controllable as the only parameter (fValue) between zero and two.  Setting the scaling factor to zero has no affect on the image.  Setting it to two (200%) will increase the sharpness of the image to the maximum degree.  To limit the noise, the result of the scaled Laplacian is only added if it is greater than a factory set limit of 75 digital numbers on 10-bit data.

For color cameras, the raw sensor data is converted to a YUV format and the sharpness filter is applied to the Y (intensity) channel only.  The modified Y intensity data combined with the UV terms and further converted to the desired output Pixel Format.  For best performance, select the YUV Pixel Format to reduce the amount of noise added to the image in the format conversions.

The sharpness filter will add noise to the image, and setting the scaling factor above 50% tends to accentuate the noise.  Noise will also increase with an increase in gain. For color cameras, YUV is preferable to Bayer when using the sharpening filter. The magnitude of the scaling factor to use is subjective.

API Control

PxLGetFeature, PxLSetFeature

Feature Flags

Parameters