这里是我根据gif图像格式想出来的判断gif图像尺寸的方法，请大家给点意见

up.htm

up.asp

<%

FormSize = Request.TotalBytes

FormData = Request.BinaryRead( FormSize )

bncrlf=chrb(13) & chrb(10)

divider=leftb(formdata,instrb(formdata,bncrlf)-1)

datastart=instrb(formdata,bncrlf & bncrlf)+4

dataend=instrb(datastart+1,formdata,divider)-datastart

Image=midb(formdata,datastart,dataend)

head_version = Ascb( midb( Image,1,3 ) )

head_subversion = Ascb( midb( Image,4,3 ) )

head_width_l = Ascb( midb( Image,7,1 ) )

head_width_h = Ascb( midb( Image,8,1 ) )

head_height_l = Ascb( midb( Image,9,1 ) )

head_height_h = Ascb( midb( Image,10,1 ) )

head_colors = Ascb( midb( Image, 11, 1 ) )

head_width_h = head_width_h * 256

head_height_h = head_height_h * 256

head_colors = head_colors And &H07

Response.Write "图像大小为" & head_width_h + head_width_l & "x" & head_height_h + head_height_l _

& "x" & 2^( head_colors + 1 )

%>