The Free, Quality Image library for Windows

ActiveX-Library: Freeimage.Image

Design and implementation by

• Markus Loibl (markus.loibl@epost.de)
   

This file is part of FreeImage 2.6.0

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Samples

Opening and saving

Option explicit

dim ctrl
dim erg

set ctrl = CreateObject("FreeImage.Image")

ctrl.Test "Opening earth.jpg and saving as a tiff .... ", "FreeImage.Image"

erg = ctrl.Open("earth.jpg")
MsgBox "Opening file result: " + CStr(erg)

erg = ctrl.Save("earth.tif")
MsgBox "Saving file result: " + CStr(erg)

set ctrl = Nothing
 

Cloning

Option explicit

dim ctrl
dim ctrl2
dim erg

set ctrl = CreateObject("FreeImage.Image")

erg = ctrl.Open("earth.jpg")

set ctrl2 = ctrl.Clone

ctrl.Test "first ok", "FreeImage.Image"
ctrl.Test "second ok", "FreeImage.Image"
 

set ctrl2 = Nothing
set ctrl = Nothing

Reference

Test

Shows a Message-Box (for testing and debugging purposes)

File handling

	Open	Loads an image. If an image is already opened, it will be closed. The image-format is calculated from the file's extension. If it is unknown, this function will fail.
in	String	Filename of image to load
out	short	0: file couldn't be loaded 1: file sucessfully loaded

	OpenEx	Loads an image. If an image is already opnened, it will be closed. If the filetype (extension) of the file is unknown, this function will fail.
in	short	Image-format
in	String	Filename of image to load
in	short	Additional parameter. They are specific to the file-format (e.g. decide which bitmap in the cabinet to load within PCD). See the freeimage-docu or sourcecode for more details!
out	short	0: file couldn't be loaded 1: file sucessfully loaded

Close

If an image is opened, it will be closed (without saving it).

	Save	Saves an opened image. The image will not be closed. The image-format is calculated from the file's extension. If it is unknown or no image is opened, this function will fail.
in	String	Filename of image to save
out	short	0: file couldn't be saved 1: file sucessfully saved

	SaveEx	Saves an opened image. The image will not be closed. If no image is opened, this function will fail.
in	short	Image-format
in	String	Filename of image to save
in	short	Additional parameter. They are specific to the file-format (e.g. decide which compression-algorithm to save using TIFF or which compression-rate while saving JPEG). See the freeimage-docu or sourcecode for more details!
out	short	0: file couldn't be saved 1: file sucessfully saved

Image-Information

If no image is opened, the following functions and properties will fail.

	ResolutionX	The horizontal image-resolution .
get/set	double	Resolution in [dpi]

	ResolutionY	The vertical image-resolution .
get/set	double	Resolution in [dpi]

	Width	The width of the image.
get	long	Width

	Height	The height of the image.
get	long	Height

	BPP	Returns the size of one pixel in the bitmap in bits. For example when each pixel takes 32-bits of space in the bitmap, this function returns 32.
get	long	BPP 1: b/w 4, 8: palette 16, 24, 32: full-coored image

	DIBSize	Returns the size of the DIB-element of a opened image in memory. E.g. the BITMAPINFOHEADER + palette + data bits.
get	long

	RedMask	Returns a bit pattern describing the red colour component of a pixel in an opened image.
get	long

	GreenMask	dto.
get	long

	BlueMask	dto.
get	long

	ColorsUsed	Returns the number of colours used in a bitmap. This function returns the palette-size for palletised bitmaps, and 0 for high-colour bitmaps. Note: It doesn’t return the actual number of colors being used in a bitmap, but the size of the palette.
get	long

	IsTransparent	Status of the transparency-table.
get	short	1: transparency table is enabled 0: else

Image-Conversions

	ChangeColors	Changes the color-model (BPP). If no image is opened or the conversion fails, this function will fail.
in	short	New BPP: 1: convert ot b/w (not yet implemented!) 8: Converts a bitmap to 8 bits. If the bitmap was a high-colour bitmap, the end result will be grayscale. 256: Quantizes a high-color bitmap to an 8-bit palletised bitmap. See the additional parameter. 16: Converts a bitmap to 16 bits. See the additional parameter. 24: Converts a bitmap to 24 bits. 32: Converts a bitmap to 32 bits.
in	short	Additional parameter. Depends on the New BPP-paramter. For 256: 0: Xiaolin Wu color quantization algorithm 1: NeuQuant neural-net quantization algorithm by Anthony Dekker For 16: 0 or 555: Each pixel has a colour pattern of 5 bits red, 5 bits green and 5 bits blue. One bit in each pixel is unused. 565: Each pixel has a colour pattern of 5 bits red, 6 bits green and 5 bits blue.
out	short	0: Failed 1: Successfully changed BPP 2: Color-model already had the specified characteristics.

	Clone	Duplicates. A new image is generated. If no image is opened or the cloning fails, this function will fail.
out	Reference to a new Freeimage.Image