Omnis Technical Note TNGI0007
Picture Conversion in Omnis 7
For Omnis 7.3 version 7
By Gary Ashford
How can I store, retrieve and display GIF and
JPG files in Omnis 7?
This document describes how you can use Omnis 7 to read images from disk, store and display them. It is adapted from previously available readme and PDF source files and has been brought up-to-date with the latest functionality
It describes the DisplayImage graphic utility, and the getpicfromimage() function.
Availability: Mac68K, PowerMac, Win16, Win32
DisplayImage is a graphic utility for use on an Omnis 7 extended area field. An extended area of this type can be used to display non-animated GIF or JPEG files, either directly by specifying a pathname or using a pre-loaded image.
The JPEG may be of any resolution and use any size of color palette from 256 to 16 million colors. The image does not adjust to fit a window. If there is an error, the image does not display and the extended area remains transparent.
Extended Area Parameters: Data Field Name, (Field Name)
Data Field Name: Not Used.
Field Name: The name of a character variable containing the full pathname of the GIF/JPEG file or the name of a binary variable containing the image data. Literal values for the pathname are not accepted.
Note: that for Win16, DisplayImage(FieldName) is entered in the Calculation field in the form of a function, e.g. DisplayImage(FV_ACHAR).
Availability: Mac68K, PowerMac, Win32 only
Syntax: getpicfromimage(pathname, mode)
Returns a Picture variable. The pathname parameter is a variable name or literal containing the path name to the GIF or JPEG file, or a binary variable containing pre-loaded image data. The mode parameter is a value specifying how the pathname argument should be interpreted: 0 if pathname is a binary variable,
or 1 if it is a character field which specifies the filename.
getpicfromimage() is an external function which can load and convert a JPEG or GIF file into an Omnis Picture variable in a single action. This function is provided by the external Wgfx.dll. getpicfromimage()
can be used to convert an image which has been pre-loaded into an Omnis binary variable.
Conversion occurs one way; from GIF or JPEG to type 'Omnis Picture'.
To display a JPEG, add a picture field to the window or report, and make it calculated, using the result of the getpicfromimage() function.
<Local variable pic (Picture
Local variable bin (Binary)
Local variable path (Character 100)
Calculate pic as
GetFile (path,"Locate a GIF/JPG file",
Calculate pic as getpicfromimage(bin,0)
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