dSaveImageJPEG (Function)

ONLINE HELP
WINDEV, WEBDEV AND WINDEV MOBILE

Version:

Home | Sign in | English

This content has been translated automatically. Click here to view the French version.

Help / WLanguage / WLanguage functions / Controls, pages and windows / Drawing functions

Image found in a Web Camera control
Drawing in browser code
Drawing in PHP

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

dSaveImageJPEG (Function)

In french: dSauveImageJPEG

Saves an image:

in a JPEG file.
in memory.

This image corresponds to the image found:

in an Image control.
in a variable of type Image.
This type of variable is not available.
in a Bar Code control.
The Bar Code controls are not available in this version. Therefore, no image found in a Bar Code control can be saved.
in a Web Camera control.

Remarks:

Only the visible part of the Image control is saved.
This function can only be used to save the images for screen resolutions up to 32 bits.
This function cannot be used with the Image controls found in the reports.
This function can also be used to save the changes made by ImageInfoModify on the Exif tags of an image.

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

In browser code, this function can only be used to save an image in memory.

Example

See additional examples

// Sauve en mémoire l'image présente dans "IMG_ImageDessin"
ResSauvegarde = dSaveImageJPEG(IMG_ImageDessin, inMemory)

// Sauve l'image présente dans "IMG_ImageDessin" sur "C:\Documents\Image.JPEG"
ResSauvegarde = dSaveImageJPEG(IMG_ImageDessin, "C:\Documents\Image.JPEG")

// Modification des commentaires de l'image
// affichée dans le champ Image "IMG_MonChampImage"
ImageInfoModify(IMG_MonChampImage, imgComment, "Belles gorgones")
// Enregistrement de la modification dans le 
// fichier "C:\Plongees\Gorgone1.JPG"
dSaveImageJPEG(IMG_MonChampImage, "C:\Plongees\Gorgone1.JPG", 100, imgSaveTag)

Syntax

Saving an image in a JPEG file Hide the details

<Result> = dSaveImageJPEG(<Image> , <File name> [, <Quality> [, <Exif tag>]])

<Result>: Boolean

True if the image was saved,
False otherwise. To get more details on the error, use ErrorInfo with the errMessage constant.

<Image>: Name of the Image control or variable

Name of the Image, Bar Code or Web Camera control to be used. Image controls in a report cannot be used.
Name of the Image or Web Camera control to be used.
Name of the Image variable to be used.
This type of variable is not available.

<File name>: Character string

Name and full (or relative) path of JPEG file. A UNC path can be used. The file extension is optional.
Caution:
The destination directory must exist in order for the image to be saved.
The existence of the JPEG file is not checked. This file is automatically overwritten if it already exists.

<Quality>: Optional integer

Quality of the image saved. Value between 1 and 100 (80 by default). Lower image quality translates into higher image compression rate and smaller file size.

<Exif tag>: Optional constant (or combination of constants)

Save the Exif tags modified by ImageInfoModify:
imgAddThumbnail Adds a thumbnail into the image file (<File name>).
If there is a thumbnail in the image file displayed in the Image control, this constant is not taken into account.
imgGrayScale Used to save the image in black and white ("Grayscale" display mode).
imgProgressiveJPEG Used to save the image in progressive JPEG format. This format is mainly used for the Web sites. It allows the pages to be loaded faster (the images being loaded and displayed progressively).
imgSaveTag Saves the Exif tags.
If there is a thumbnail in the image file displayed in the Image control, a new thumbnail is recalculated.

By default, the Exif tags are not saved, no operation is performed on the thumbnails.
This parameter is not available.

Saving an image in memory Hide the details

<Result> = dSaveImageJPEG(<Image> , <inMemory> [, <Quality> [, <Exif tag>]])

<Result>: Buffer

Byte string containing the image in JPEG format.
Then this byte string can be assigned to an Image control, saved in a file (fSaveText), sent via a network (with the Socket functions), ...
In browser code, this byte string can only be assigned to another image ("Localize the image in the _WEB directory in browser code" must be unchecked). It cannot be saved in a file to build an image file.

<Image>: Name of the Image control or variable

Name of the Image, Bar Code or Web Camera control to be used. Image controls in a report cannot be used.
Name of the Image or Web Camera control to be used.
Name of the Image variable to be used.
This type of variable is not available.

<inMemory>: Constant

inMemory: Constant used to save an image in memory.

<Quality>: Optional integer

Quality of the image saved. Value between 1 and 100 (80 by default). Lower image quality translates into higher image compression rate and smaller file size.

<Exif tag>: Optional constant (or combination of constants)

Save the Exif tags modified by ImageInfoModify:
imgAddThumbnail Adds a thumbnail into the image file (<File name>).
If there is a thumbnail in the image file displayed in the Image control, this constant is not taken into account.
imgProgressiveJPEG Used to save the image in progressive JPEG format. This format is mainly used for the Web sites. It allows the pages to be loaded faster (the images being loaded and displayed progressively).
imgSaveTag Saves the Exif tags.
If there is a thumbnail in the image file displayed in the Image control, a new thumbnail is recalculated.

By default, the Exif tags are not saved, no operation is performed on the thumbnails.
This parameter is available only if <Control name> corresponds to the name of an Image control.
This parameter is not available.

Remarks

Image found in a Web Camera control

Only the image displayed when dSaveImageJPEG is executed is saved. To save this image, you can also use:

the VideoCapture function: the image will be saved as a BMP file
the dSaveImageBMP function: the image will be saved in BMP format or in memory
the dSaveImageGIF function: the image will be saved in GIF format or in memory
the dSaveImagePNG function: the image will be saved in PNG format or in memory.

Drawing in browser code

The image saved in memory can be directly assigned to an Image control. Depending on the browser used, the result may not be the expected one.

For example, with the current version of FireFox and Opera (available when this documentation was published), images in JPEG format are not displayed properly (they are displayed on a black background).

This operating mode may be improved during the next upgraded versions of these browsers.

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.

Component: wd300pnt.dll