BuildPalette

The BuildPalette function rebuilds image palette in accordance with real image colors.

BuildPalette nImportantColors

Parameters

nImportantColors
Specifies the number of impotant colors in the image. These are first nImportantColors colors in the image palette. These palette entries will not be changed.

Remarks

ShotGraph imagespace contains a true color image. However, some image file formats supports only a number of colors in the image (palette). Making such image, usually you need to degrade the amount of colors in the imagespace. If colors of image pixels in the imagespace don't match the colors declared by SetColor method or if colors of image pixels are unknown then use this method. This method reconstructs image palette and changes its entries except first nImportantColors colors.
Call this method once in your script just before calling GifImage or other function creating paletted images. This improves the image quality in case if you used some operations which can add other colors into imagespace, like the following:

See too

CreateImage, SetColor
Example

<%@ Language=VBScript %>
<%
Response.ContentType="image/gif"
set obj=Server.CreateObject("shotgraph.image")
size=100
obj.CreateImage size,size,16
obj.SetColor 0,255,255,255
obj.SetColor 1,0,0,0
obj.SetColor 2,255,108,0
obj.SetBgColor 0
obj.FillRect 0,0,size-1,size-1

obj.SetTextAlign "TA_CENTER","TA_BASELINE"
obj.SetBkColor 0
obj.SetTextColor 1
obj.CreateFont "Arial",0,22,0,True,False,False,False
obj.TextOut size/2,24,"Text1"
obj.SetTextColor 2
obj.CreateFont "Arial",0,15,0,True,False,False,False
obj.TextOut size/2,size/2,"Text2"

obj.BuildPalette 3

img=obj.GifImage(-1,1,"")
Response.BinaryWrite(img)
%>
Results:
Without BuildPalette With BuildPalette