Image manipulation API

The task of image manipulation is quite common in Smart Devices applications. Common actions include: resizing, scaling, rotating, cropping, flipping horizontally and vertically, etc.

To allow the performance of such actions on images, GeneXus has added certain functions to the Image data type.

Properties

ImageWidth: Numeric

Read-only property. Returns the image width in pixels.

&width = &image.ImageWidth

 

ImageHeight: Numeric

Read-only property. Returns the image height in pixels.

&height = &image.ImageHeight

 

FileSize: Numeric

Read-only property. Returns the image's file size in bytes.

&fileSize = &image.FileSize

 

Methods

Resize

Returns a new image by resizing the original image.

Parameters:

• Width: Numeric - width of the new image,
• Height: Numeric - height of the new image,
• KeepAspect: Boolean, if set to True, then the image is resized using "fill keeping aspect". Otherwise, it uses "fill".

&resizedImage = &image.Resize(100, 100, true)

Scale

Returns a new image by scaling the original image in the specified percentage.

Parameters:

• Percentage: Numeric.

&scaledImage = &image.Scale(80)

Rotate

Returns a new image by rotating the original image in the specified angle. Valid angles are 90, 180 and 270 degrees; other values are ignored.

Parameters:

• Angle: Numeric.

&rotatedImage = &image.Rotate(90)

Crop

Returns a new image by cropping the original image. The dimensions of the new image are determined from the square indicated by the parameters.

Parameters:

• Left: Numeric - left coordinate in pixels where the cropping begins.
• Top: Numeric - top coordinate in pixels where the cropping begins.
• Width: Numeric - width of the new image in pixels.
• Height: Numeric - height of the new image in pixels.

&croppedImage = &image.Crop(0, 0, 50, 50)

FlipHorizontally

Flips the image horizontally.

&hFlippedImage = &image.FlipHorizontally()

FlipVertically

Flips the image vertically.

&vFlippedImage = &image.FlipVertically()

Availability 

These properties and methods are available for iOS since GeneXus 16 upgrade 2.

These properties and methods are available for Android since GeneXus 16 Upgrade 11.

These properties and methods are available for Web since GeneXus 17 Upgrade 5.

Scope

 

See also 

Image data type