dModifyLightness (Function)

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dModifyLightness (Function)

In french: dModifieLuminosité

Changes the lightness of an image found:

in an Image control,
in a variable of type Image.
This type of variable is not available.

Caution: A specific configuration is required to use this function in Linux. For more details, see The drawings.

Example

// Change the lightness of the image found in IMG_Image1
dModifyLightness(IMG_Image1, 50)

Syntax

<Result> = dModifyLightness(<Source image> , <Variation of lightness> [, <Destination image>])

<Result>: Boolean

True if the change was performed,
False otherwise.

<Source image>: Name of the Image control or variable

Image to use. The image can correspond to:
the name of an Image control.
the name of a variable of type Image.
This type of variable is not available.

<Variation of lightness>: Integer

Value between -100 and +100. This value will be added to the current lightness of each pixel to get a new lightness.

<Destination image>: Optional control name or optional Image variable

Image where the transformed image will be drawn. The image can correspond to:
the name of an Image control.
the name of a variable of type Image.
This type of variable is not available.
If this parameter is not specified, the transformation will be performed on the <Source image>.

Remarks

Drawing in PHP

In PHP, the drawing functions are based on the graphic library GD. This library is commonly used by the PHP hosting providers and therefore it is always enabled. The version of the GD library must be version 2.0.28 (or later). This library can be downloaded from the PHP site.

To enable (if necessary) this library locally, the following elements are required:

PHP installed.
the PHP.INI file found in the Windows directory must contain the following line: "extension=php_gd2.dll" (instead of ";extension=php_gd2.dll").
the php_gd2.dll file must exist in the directory of PHP extensions. This directory is defined in the PHP.INI file by the "extension_dir" variable.

Drawing in Browser code

Some drawing functions are available in Browser code. The drawing functions in Browser code are based on the HTML 5 standard. More specifically, these functions are based on the "canvas" tag of HTML 5.

The drawing features in browser code are available for the recent browsers only (supporting the HTML 5 standard). To find out whether the drawing features are proposed by your browser, use DrawingAvailable.

Caution: To use the drawing functions with Internet Explorer 9, the project must include the reference to the DTD file. To do so, the HTML mode must be "HTML 4.01 Transitional + DTD". This option is available in the "Advanced" tab of the project description window.
Reminder: To open the project description window, go to the "Project" tab, "Project" group and click "Description".

Special case: Drawing in the browser of an Android phone: The browser drawing functions are only available starting with version 3 of Android.

Component: wd300pnt.dll