Routines (alphabetical) > Object Classes > Graphics Object Classes > IDLgrShaderConvol3 Properties

# IDLgrShaderConvol3 Properties

IDLgrShaderConvol3 objects have the following properties in addition to properties inherited from any superclasses. Properties with the word “Yes” in the “Get” column of the property table can be retrieved via IDLgrShaderConvol3::GetProperty. Properties with the word “Yes” in the “Init” column of the property table can be set via IDLgrShaderConvol3::Init. Properties with the word “Yes” in the “Set” column in the property table can be set via IDLgrShaderConvol3::SetProperty.

Note: For a discussion of the property description tables shown below, see About Object Property Descriptions.

Objects of this class have the following properties.

- BASE_BLEND_FACTOR
- CONVOL_BLEND_FACTOR
- KERNEL

In addition, objects of this class inherit the properties of IDLgrShader.

### BASE_BLEND_FACTOR

A scalar single-precision floating-point value in the range of [0.0, 1.0] with a default value of 0.0. Setting this property to a numeric value outside of this range results in an error. This property controls the amount of the base image that is added to the kernel output, controlled by the CONVOL_BLEND_FACTOR property, in the final resulting image. The default value of 0.0 implies that no part of the base image is added to the final image.

Note: Some convolution kernels work best when combining the kernel output with the original base image. The sharpen convolution kernel (KERNEL=2) is a good example. The default value of 0.0, causes no contribution of the base image with the kernel output, while a value of 1.0 adds all of the base image to the kernel output.

Property Type | Float
Name String | not displayed
Get: Yes | Set: Yes | Init: Yes | Registered: No

### CONVOL_BLEND_FACTOR

A scalar single-precision floating-point value in the range [0.0, 1.0]. This property controls the amount of the convolution kernel output that is added to the base image, controlled by the BASE_BLEND_FACTOR property, in the final resulting image. Setting this property to a numeric value outside of the 0.0 to 1.0 range results in an error. The default value is 1.0, which implies that all of the convolution output is added to the final image.

Property Type | Float
Name String | not displayed
Get: Yes | Set: Yes | Init: Yes | Registered: No

### KERNEL

Either a scalar integer value indicating a pre-defined kernel, or a 9-element numerical array (that will be converted to a 3x3 floating-point array) containing a custom kernel. The predefined kernels are:

Value | Description
0 | Identity (performs no operation on the image) - the default
1 | Smooth
2 | Sharpen
3 | Edge Detection (vertical and horizontal)

The default value, 0, selects the “identity” kernel, which passes the image through without modification. This property may also be set with a 9-element numeric array. IDL converts this array to single-precision floating-point. Setting this property with any value other than a pre-defined kernel or a 9-element numeric array results in an error.

If this property is set with a scalar integer, GetProperty returns the same scalar integer. If this property is set with a 9-element numeric array, GetProperty returns a 9-element floating-point array.

Property Type | Integer or Array
Name String | not displayed
Get: Yes | Set: Yes | Init: Yes | Registered: No