ImageInfoModify (Function)

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Correspondence between tags and constants
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Exif functions

ImageInfoModify (Function)

In french: ImageInfoModifie

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

This modification is performed in memory. To save this modification, use ImageInfoSave or dSaveImageJPEG.

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.
If the specified Exif tag does not exist for the image used, this tag is added to the image.
Some specific tags (the "Offsets" for instance) cannot be modified. In this case, the modification is ignored (<Result> = False).
To handle the Exif tags of an image, use the Exif property of Image variables. This property can be used on Android applications.

Example

CheminImg is string = "C:\Mes Images\MonImage.JPG" 
// Modification du copyright
// Ce marqueur existe. Le type actuel de ce marqueur sera utilisé  
ImageInfoModify(CheminImg, imgCopyright, "PC Soft " + Today()) 
// Enregistrement de la modification
ImageInfoSave(CheminImg)
// Fermeture du fichier image
ImageInfoClose(CheminImg)

// Modification des commentaires de l'image JPEG
// affichée dans le champ Image "IMG_MonChampImage"
// Le marqueur "imgCommentaire" n'existe pas, il sera rajouté. 
// Le type "ExifChaîne" sera automatiquement déduit
// à partir de la chaîne contenant les commentaires
ImageInfoModify(IMG_MonChampImage, imgComment, "Belles gorgones") 
// Enregistrement de la modification
ImageInfoSave(IMG_MonChampImage, "C:\Plongees\Gorgone1.JPG")

CheminImg is string = "C:\Mes Images\Chien1.JPG" 
// Modification de la focale
// Si ce marqueur n'existe pas, la valeur de la focale
// sera enregistrée sous forme de rationnel signé
// Si ce marqueur existe, le type actuel de ce
// marqueur sera utilisé
ImageInfoModify(CheminImg, imgFAperture, 2.8, ExifRational) 
// Enregistrement de la modification
ImageInfoSave(CheminImg)
// Fermeture du fichier image
ImageInfoClose(CheminImg)

Syntax

<Result> = ImageInfoModify(<Image> , <Tag> , <New value> [, <Type of Tag>])

<Result>: Boolean

True if the modification was performed,
False otherwise.

<Image>: Character string

Image to use. This image can correspond to:
an image file (JPEG 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 displayed in an Image control: specify the name of the Image control. If this image is not in JPEG format, this image will be automatically converted to this format during its backup (ImageInfoSave or dSaveImageJPEG).
an image (JPEG format) contained in a picture memo: specify the picture memo.
an image (JPEG format) contained in a binary string: specify this binary string.

<Tag>: Constant or integer

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

<New value>: Type of the value of the tag to modify

New value for the specified tag.

<Type of Tag>: Optional integer constant

Type in which the value of the tag will be saved:
ExifBinary Binary string
ExifInteger4 4-byte signed integer
ExifRational Signed rational
ExifString ASCII character string
ExifUInteger1 1-byte unsigned integer
ExifUInteger2 2-byte unsigned integer
ExifUInteger4 4-byte unsigned integer
ExifURational Unsigned rational

If the modified tag already exists for the image used, this parameter will be ignored and the current type of the modified tag will be used.
If the modified tag does not exist for the image used, we advise you to specify the tag type. Otherwise, the default type will be automatically deduced from <New Value>.

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 Image Copyright
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: 1 to 4: landscape. 5 to 8: portrait.
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: meadow 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.

Handling errors

ImageInfoModify 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.

Component: wd300img.dll