PngImage

The PngImage method writes the whole image or its part to PNG format.

PngImage vTransparent, vColorMode, sFileName [,nXStart] [,nYStart] [,Width] [,Height]

Parameters

vTransparent
Specifies the transparent color number in the image (from colors earlier defined by SetColor). If you want your image to have no transparent color, set this value to -1.

vColorMode
Specifies whether PNG file will be true color image (0) or paletted image (1).

sFileName
String specifying the name of the file to write to. If sFileName is a zero length string, the resulting PNG image will be produces as SAFEARRAY return value. You can use this for generation of images with ASP and sending them to client instead of writing to file.

nXStart
Specifies the x-coordinate of the first base corner of the bounding rectangle

nYStart
Specifies the y-coordinate of the first base corner of the bounding rectangle

Width
Specifies the width of image bounding rectangle

Height
Specifies the height of image bounding rectangle

Return Value

This method returns binary PNG image, if sFileName parameter is zero length string.

Remarks

For generation of images with ASP on the fly and sending them to client use BinaryWrite method of Response object.
If you have not specified the image sizes, the whole image in the primary imagespace will be used to create PNG.
If you create paletted PNG file you may want to call the BuildPalette or ApplyPalette methods just before PngImage in cases when real image colors don't match colors declared by SetColor calls.

Example

<%
Response.ContentType = "image/png"
Set g = CreateObject("shotgraph.image")
g.CreateImage 320,240,8
...............
' Create true color PNG image
Response.BinaryWrite g.PngImage(-1,0,"")
%>