ImageInfoValue (Function)

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Correspondence between tags and constants
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Exif functions

ImageInfoValue (Function)

In french: ImageInfoValeur

Returns the value of an Exif tag for the image used.

Remarks:

The Exif (EXchangeable Image File) information is included in the image file. This standard defines a set of markers for storing a wide range of image-related information: date, width, orientation, camera model, shutter speed, subject distance, exposure time, etc.
To handle the Exif tags of an image, use the Exif property of Image variables. This property can be used on Android applications.

Example

ListeMarqueur is string 
MonMarqueur is int 
i is int = 1 
// Récupération des marqueurs disponibles pour 
// l'image JPEG affichée dans le champ Image "IMG_MonChampImage" 
ListeMarqueur = ImageInfoList(IMG_MonChampImage) 
WHILE ExtractString(ListeMarqueur, i, CR) <> EOT 
	// Récupération de chaque marqueur 
	MonMarqueur = ExtractString(ListeMarqueur, i, CR) 
	// Ajout du marqueur et de sa valeur dans la table TABLE_MaTable 
	TableAddLine(TABLE_MaTable, MonMarqueur, ... 
		ImageInfoValue(IMG_MonChampImage, MonMarqueur)) 
	i ++ 
END

CheminImg is string = "C:\Mes Images\MonImage.JPG"
// Connaître la date de réalisation de cette image 
Info("Date de réalisation : " + ImageInfoValue(CheminImg, imgDate) + CR + ...
	"Luminosité : " + ImageInfoValue(CheminImg, imgBrightness) + CR + ...
	"Longueur focale : " + ImageInfoValue(CheminImg, imgFocalLength) + CR + ...
	"Ouverture : " + ImageInfoValue(CheminImg, imgAperture)) 
// Fermeture du fichier image 
ImageInfoClose(CheminImg)

Syntax

<Result> = ImageInfoValue(<Image> , <Tag>)

<Result>: Buffer

Value of the specified tag for the image used.

<Image>: Character string

Image to use. This image can correspond to:
an image file (JPEG or TIFF format): specify the name and full (or relative) path of the file. A UNC path can be used.
In this case, the file must be closed by ImageInfoClose.
an image (JPEG or TIFF format) displayed in an Image control: specify the name of the Image control.
an image (JPEG or TIFF format) contained in a picture memo: specify the picture memo.
an image (JPEG or TIFF format) contained in a binary string: specify this binary string.

<Tag>: Constant or integer

Tag whose value you want to get. This tag can correspond to:
an integer given by ImageInfoList.
a WLanguage constant. For more details, see "Correspondence between tags and constants".

Remarks

Correspondence between tags and constants

The table below presents the correspondence between tags and WLanguage constants.

Tag	WLanguage constant	Value

37510	imgComment	Character string Comments about the image
37122	imgCompression	Real Compression of the image in bits/pixel
33432	imgCopyright	Character string Copyright of the image
306	imgDate	Date Date and time of the image in YYYY:MM:DD HH:MM:SS format
270	imgDescription	Character string Image description
37382	imgSubjectDistance	Real Distance from the subject in meters
37380	imgExposureBias	Real Exposure bias in APEX
37385	imgFlash	Integer Status of the flash during the shot: 0: Flash not fired. 1: Flash off. 5: Flash triggered and return light not detected. 7: Flash triggered and return light detected.
928	imgHeight	Integer Image height in pixels
672	imgWidth	Integer Image width in pixels
305	imgRecordingSoftware	Character string Name of the software that was used to record the image.
37386	imgFocalLength	Real Focal length in millimeters
37379	imgBrightness	Real Brightness of the image in APEX
271	imgDeviceMark	Character string Mark of the camera that took the photo
272	imgDeviceModel	Character string Model of camera that took the photo
37383	imgMeteringMode	Integer Metering mode: 0: unknown. 1: average. 2: centered average. 3: point. 4: multipoint. 5: motif. 6: partial. 7 to 254: reserved. 255: other.
37500	imgManufacturerNote	Character string Name of the camera manufacturer
274	imgOrientation	Integer Orientation of the image: This information indicates the location of the point (0,0) in the image. To display the image in the correct direction based on this information, use the following values: 1: the point (0,0) is at the top left of the transformed image, so there's nothing to do. 2: the point (0,0) is at the top right of the transformed image, so we need to perform vertical symmetry. 3: the point (0,0) is at bottom right in the transformed image, so we need to perform horizontal and vertical symmetry. 4: the point (0,0) is at bottom left in the transformed image, so we need to perform horizontal symmetry. 5: the point (0,0) is on the left and at the top of the transformed image, so we need to perform a horizontal symmetry and a 90° rotation. 6: the point (0,0) is on the right and at the top of the transformed image, so a 90° rotation is required. 7: the point (0,0) is on the right and at the bottom of the transformed image, so we need to perform a vertical symmetry and a 90° rotation. 8: the point (0,0) is on the left and at the bottom of the transformed image, so we need to rotate it by -90°.
37378	imgAperture	Real Aperture in APEX
33437	imgFAperture	Real Focal
37381	imgMaxAperture	Real Maximum aperture in APEX
34850	imgExposureProgram	Integer Exposure mode used during the shot: 0: undefined. 1: manual. 2: normal. 3: aperture priority. 4: speed priority. 5: creative. 6: action. 7: close-up portrait without background. 8: landscape. 9 to 255: other.
282	imgXResolution	Real Horizontal resolution of the image
283	imgYResolution	Real Vertical resolution of the image
37384	imgLightSource	Integer Light source for the image: 0: unknown. 1: daylight. 2: fluorescent. 3: tungsten. 17: standard light A. 18: standard light B. 19: standard light C. 20: D55. 21: D65. 22: D75. 23 to 254: reserved. 255: other.
33434	imgExposureTime	Real Exposure time
296	imgResolutionUnit	Integer Unit for the horizontal and vertical resolution of the image: 2: inches. 3: centimetres.
36864	imgEXIFVersion	Character string Version of Exif information
65536	imgThumbnail	Binary string Thumbnail corresponding to the image
37377	imgShutterSpeed	Real Shutter speed in APEX

Other tags are also available. These unlisted tags are specific to some types of cameras or correspond to custom tags.

Error management

ImageInfoValue returns no error code. To determine if this function generated an error, use the ErrorOccurred variable. If an error occurs, you can get more details on the error with ErrorInfo.

Related Examples:

Unit examples (WINDEV): The EXIF functions

[ + ] Using the ImageXXX functions.
These functions are used to access the EXIF information of an image.
The EXIF information is included in the JPEG or TIFF images.
It can be for example the snapshot date, the orientation of the device when taking the photo, the make and model of the camera, a miniature of the image...

Component: wd300img.dll