GMImage.MultiplyChannel

Multiplies all values in a channel.

Parameters

Parameter	Description	Example	Flags
ImageRef	The image reference number.	1
Channel	Which channel to work with. Can be opacity, red, green or blue. The value rgb will apply effect to all three color channels.	"rgb"
Factor	The multiplication factor. Range from -1.0 to 1.0.	0.1
Add1	The value to add before multiply. Usually between -65535 and 65535.	0	Optional
Add2	The value to add after multiply. Usually in range from -65535 to 65535.	65535*0.9	Optional

Result

Returns OK or error.

Description

Examples

Multiplies existing opacity channel to make image 90% transparent:

// existing values * 0.1 and add 90% to the value to move to higher range.
MBS("GMimage.MultiplyChannel"; $ImageRef; "opacity"; 0.1; 0; 255*0.9)

Invert image via multiply:

Set Variable [ $image ; Value: MBS( "GMImage.NewFromContainer"; Invert::Input ) ]
# each channel...
// Set Variable [ $r ; Value: MBS( "GMImage.MultiplyChannel"; $image; "red"; -1; 0; 65535) ]
// Set Variable [ $r ; Value: MBS( "GMImage.MultiplyChannel"; $image; "green"; -1; 0; 65535) ]
// Set Variable [ $r ; Value: MBS( "GMImage.MultiplyChannel"; $image; "blue"; -1; 0; 65535) ]
# all channels...
Set Variable [ $r ; Value: MBS( "GMImage.MultiplyChannel"; $image; "rgb"; -1; 0; 65535) ]
Set Field [ Invert::Output ; MBS( "GMImage.WriteToPNGContainer"; $image; "output.png") ]
Set Variable [ $r ; Value: MBS( "GMImage.Release"; $image) ]

See also

• GMImage.InvertChannel
• GMImage.New
• GMImage.NewFromContainer
• GMImage.Release
• GMImage.WriteToPNGContainer

Release notes

• Version 8.4
  • Fixed GMImage.MultiplyChannel for 16-bit colors.

Example Databases

• GraphicsMagick/Annotate Image
• GraphicsMagick/Invert

Blog Entries

• MBS FileMaker Plugin, version 8.4pr1
• MBS FileMaker Plugin, version 5.0pr10

This function checks for a license.

Created 3th February 2015, last changed 11st November 2019

GMImage.MotionBlur - GMImage.Negate