GMImage.Threshold

Threshold image channels (below threshold becomes black, above threshold becomes white).

Parameters

Parameter	Description	Example	Flags
ImageRef	The image reference number.	1
threshold	The range of the threshold parameter is 0 to MaxRGB (65535).	127*256	Optional

Result

Returns "OK" on success.

Description

Examples

Applies a threshold on the image:

Let ( [
$Image = MBS("GMImage.NewFromContainer"; GraphicsMagick::image);
$Result = MBS("GMImage.Threshold";$Image; 127);
$Result = MBS("GMImage.WriteToJPEGContainer"; $Image);
$Error = MBS("GMImage.Release";$Image)
];
$Result)

Convert image to 1 bit TIFF:

# Load from container
$Image = MBS("GMImage.NewFromContainer"; GraphicsMagick::image);

# make black and white with threshold
$Result = MBS("GMImage.Threshold";$Image; 127);

# mark as monochrome image
$Result = MBS("GMImage.SetMonochrome";$Image; 1);

# set type to 1 for black/white
$Result = MBS("GMImage.SetType";$Image; 1);

# set to use TIFF for compression
$Result = MBS("GMImage.SetMagick";$Image; "TIFF");

# set to use CCITT 4 Fax compression
$Result = MBS("GMImage.SetCompressType";$Image; 4);

# and write to a file
$Result = MBS("GMImage.WriteToFile"; $Image; "/tmp/test.tif");

# cleanup
$Error = MBS("GMImage.Release";$Image)

Make a picture black and transparent:

Set Variable [$image; Value:MBS( "GMImage.NewFromContainer"; Test::BigImage)]
Set Variable [$r; Value:MBS( "GMImage.Threshold"; $image; 127)]
Set Variable [$imagecolor; Value:MBS( "GMImage.Transparent"; $image; "white")]
Set Field [Test::Result; MBS( "GMImage.WriteToPNGContainer"; $image;)]
Set Variable [$Error; Value:MBS("GMImage.Release";$image)]

See also

• GMImage.New
• GMImage.Release
• GMImage.SetCompressType
• GMImage.SetMagick
• GMImage.SetType
• GMImage.Transparent
• GMImage.WriteToFile
• GMImage.WriteToJPEGContainer
• GMImage.WriteToPNGContainer
• GMImage.WriteToTiffContainer

Example Databases

• GraphicsMagick/GraphicsMagick Sample

Blog Entries

• GraphicsMagick in FileMaker, part 9
• GraphicsMagick in FileMaker, part 8

This function checks for a license.

Created 18th August 2014, last changed 11st November 2019

GMImage.Texture - GMImage.TotalColors