Asp无组件生成缩略图

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’//////////// GPS：Get Picture Size //////////////

’//////////////利用ADODB.stream获取图片尺寸//////////////

’/////////Cited By Leon（心晴） 2005年8月11日//////////

Class GPS

Dim aso

Private Sub Class_Initialize

Set aso=CreateObject(Adodb.Stream)

aso.Mode=3

aso.Type=1

aso.Open

End Sub

Private Sub Class_Terminate

set aso=nothing

End Sub

Private Function Bin2Str(Bin)

Dim I, Str

For I=1 to LenB(Bin)

clow=MidB(Bin,I,1)

if AscB(clow)<128 then

Str = Str & Chr(ASCB(clow))

Else

I=I 1

if I <= LenB(Bin) then Str = Str & Chr(ASCW(MidB(Bin,I,1)&clow))

end If

Next

Bin2Str = Str

End Function

Private Function Num2Str(num,base,lens)

’GPS (2005-8-11)

dim ret

ret =

while(num>=base)

ret = (num mod base) & ret

num = (num - num mod base)/base

wend

Num2Str = right(string(lens,0) & num & ret,lens)

End Function

Private Function Str2Num(str,base)

’GPS (2005-8-11)

dim ret

ret = 0

for i=1 to len(str)

ret = ret *base cint(mid(str,i,1))

next

Str2Num=ret

End Function

Private Function BinVal(bin)

’GPS (2002-8-11)

dim ret

ret = 0

for i = lenb(bin) to 1 step -1

ret = ret *256 ascb(midb(bin,i,1))

next

BinVal=ret

End Function

Private Function BinVal2(bin)

’GPS (2002-8-11)

dim ret

ret = 0

for i = 1 to lenb(bin)

ret = ret *256 ascb(midb(bin,i,1))

next

BinVal2=ret

End Function

’///以下是调用代码///

Function getImageSize(filespec)

’GPS (2002-8-11)

dim ret(3)

aso.LoadFromFile(filespec)

bFlag=aso.read(3)

select case hex(binVal(bFlag))

case 4E5089:

aso.read(15)

ret(0)=PNG

ret(1)=BinVal2(aso.read(2))

aso.read(2)

ret(2)=BinVal2(aso.read(2))

case 464947:

aso.read(3)

ret(0)=GIF

ret(1)=BinVal(aso.read(2))

ret(2)=BinVal(aso.read(2))

case 535746:

aso.read(5)

binData=aso.Read(1)

sConv=Num2Str(ascb(binData),2 ,8)

nBits=Str2Num(left(sConv,5),2)

sConv=mid(sConv,6)

while(len(sConv)<nBits*4)

binData=aso.Read(1)

sConv=sConv&Num2Str(ascb(binData),2 ,8)

wend

ret(0)=SWF

ret(1)=int(abs(Str2Num(mid(sConv,1*nBits 1,nBits),2)-Str2Num(mid(sConv,0*nBits 1,nBits),2))/20)

ret(2)=int(abs(Str2Num(mid(sConv,3*nBits 1,nBits),2)-Str2Num(mid(sConv,2*nBits 1,nBits),2))/20)

case FFD8FF:

do

do: p1=binVal(aso.Read(1)): loop while p1=255 and not aso.EOS

if p1>191 and p1<196 then exit do else aso.read(binval2(aso.Read(2))-2)

do:p1=binVal(aso.Read(1)):loop while p1<255 and not aso.EOS

loop while true

aso.Read(3)

ret(0)=JPG

ret(2)=binval2(aso.Read(2))

ret(1)=binval2(aso.Read(2))

case else:

if left(Bin2Str(bFlag),2)=BM then

aso.Read(15)

ret(0)=BMP

ret(1)=binval(aso.Read(4))

ret(2)=binval(aso.Read(4))

else

ret(0)=

end if

end select

ret(3)=width= & ret(1) & height=

& ret(2) &

getimagesize=ret

End Function

End Class

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