[VB6] In memory convert to JPEG using WIC

[wqweto]

This uses Windows Imaging Component to convert a bitmap (a 32-bit DIB) to a JPEG stream purely in memory.

Paste the following code in a .bas module:

Option Explicit

Private Declare Function SHCreateMemStream Lib "shlwapi" Alias "#12" (pInit As Any, ByVal cbInit As Long) As stdole.IUnknown
Private Declare Function IStream_Size Lib "shlwapi" (ByVal pStream As stdole.IUnknown, uiSize As Any) As Long
Private Declare Function IStream_Reset Lib "shlwapi" (ByVal pStream As stdole.IUnknown) As Long
Private Declare Function IStream_Read Lib "shlwapi" (ByVal pStream As stdole.IUnknown, pvBuf As Any, ByVal cbSize As Long) As Long
'--- WIC
Private Declare Function WICCreateImagingFactory_Proxy Lib "windowscodecs" (ByVal SDKVersion As Long, ppIImagingFactory As stdole.IUnknown) As Long
Private Declare Function IWICImagingFactory_CreateStream_Proxy Lib "windowscodecs" (ByVal pFactory As stdole.IUnknown, ppIWICStream As stdole.IUnknown) As Long
Private Declare Function IWICImagingFactory_CreateEncoder_Proxy Lib "windowscodecs" (ByVal pFactory As stdole.IUnknown, guidContainerFormat As Any, pguidVendor As Any, ppIEncoder As stdole.IUnknown) As Long
Private Declare Function IWICImagingFactory_CreateBitmapFromMemory_Proxy Lib "windowscodecs" (ByVal pFactory As stdole.IUnknown, ByVal uiWidth As Long, ByVal uiHeight As Long, pixelFormat As Any, ByVal cbStride As Long, ByVal cbBufferSize As Long, pbBuffer As Any, ppIBitmap As stdole.IUnknown) As Long
Private Declare Function IWICStream_InitializeFromIStream_Proxy Lib "windowscodecs" (ByVal pIWICStream As stdole.IUnknown, ByVal pIStream As stdole.IUnknown) As Long
Private Declare Function IWICBitmapEncoder_Initialize_Proxy Lib "windowscodecs" (ByVal pIEncoder As stdole.IUnknown, ByVal pIStream As stdole.IUnknown, ByVal cacheOption As Long) As Long
Private Declare Function IWICBitmapEncoder_CreateNewFrame_Proxy Lib "windowscodecs" (ByVal pIEncoder As stdole.IUnknown, ppIFrameEncode As stdole.IUnknown, ppIEncoderOptions As stdole.IUnknown) As Long
Private Declare Function IWICBitmapEncoder_Commit_Proxy Lib "windowscodecs" (ByVal pIEncoder As stdole.IUnknown) As Long
Private Declare Function IWICBitmapFrameEncode_Initialize_Proxy Lib "windowscodecs" (ByVal pIFrameEncode As stdole.IUnknown, ByVal pIEncoderOptions As stdole.IUnknown) As Long
Private Declare Function IWICBitmapFrameEncode_SetSize_Proxy Lib "windowscodecs" (ByVal pIFrameEncode As stdole.IUnknown, ByVal uiWidth As Long, ByVal uiHeight As Long) As Long
Private Declare Function IWICBitmapFrameEncode_WriteSource_Proxy Lib "windowscodecs" (ByVal pIFrameEncode As stdole.IUnknown, ByVal pIBitmapSource As stdole.IUnknown, pWicRect As Any) As Long
Private Declare Function IWICBitmapFrameEncode_Commit_Proxy Lib "windowscodecs" (ByVal pIFrameEncode As stdole.IUnknown) As Long
Private Declare Function IPropertyBag2_Write_Proxy Lib "windowscodecs" (ByVal pPropBag As stdole.IUnknown, ByVal cProperties As Long, pBag As Any, pvarValue As Variant) As Long

Private m_pWicFactory           As stdole.IUnknown

Public Function WicConvertToJpeg(baOutput() As Byte, ByVal lWidth As Long, ByVal lHeight As Long, baInput() As Byte, ByVal lQuality As Long) As Boolean
    Const WINCODEC_SDK_VERSION1   As Long = &H236&
    Const WINCODEC_SDK_VERSION2   As Long = &H237&
    Const WICBitmapEncoderNoCache As Long = 2
    Dim aGUID(0 To 3)   As Long
    Dim pBitmap         As stdole.IUnknown
    Dim pWicStream      As stdole.IUnknown
    Dim pStream         As stdole.IUnknown
    Dim pEncoder        As stdole.IUnknown
    Dim pFrame          As stdole.IUnknown
    Dim pPropBag        As stdole.IUnknown
    Dim cSize           As Currency
    Dim aBag(0 To 7)    As Long
    
    On Error GoTo EH
    If m_pWicFactory Is Nothing Then
        If WICCreateImagingFactory_Proxy(WINCODEC_SDK_VERSION2, m_pWicFactory) < 0 Then
            If pvCheckHResult(WICCreateImagingFactory_Proxy(WINCODEC_SDK_VERSION1, m_pWicFactory)) < 0 Then
                GoTo QH
            End If
        End If
    End If
    '--- GUID_WICPixelFormat32bppPBGRA
    aGUID(0) = &H6FDDC324
    aGUID(1) = &H4BFE4E03
    aGUID(2) = &H773D85B1
    aGUID(3) = &H10C98D76
    If pvCheckHResult(IWICImagingFactory_CreateBitmapFromMemory_Proxy(m_pWicFactory, lWidth, lHeight, aGUID(0), lWidth * 4, UBound(baInput) + 1, baInput(0), pBitmap)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICImagingFactory_CreateStream_Proxy(m_pWicFactory, pWicStream)) < 0 Then
        GoTo QH
    End If
    Set pStream = SHCreateMemStream(ByVal 0, 0)
    If pvCheckHResult(IWICStream_InitializeFromIStream_Proxy(pWicStream, pStream)) < 0 Then
        GoTo QH
    End If
    '--- GUID_ContainerFormatJpeg
    aGUID(0) = &H19E4A5AA
    aGUID(1) = &H4FC55662
    aGUID(2) = &H5817C0A0
    aGUID(3) = &H57108E02
    If pvCheckHResult(IWICImagingFactory_CreateEncoder_Proxy(m_pWicFactory, aGUID(0), ByVal 0, pEncoder)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapEncoder_Initialize_Proxy(pEncoder, pWicStream, WICBitmapEncoderNoCache)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapEncoder_CreateNewFrame_Proxy(pEncoder, pFrame, pPropBag)) < 0 Then
        GoTo QH
    End If
    aBag(3) = StrPtr("ImageQuality")
    If pvCheckHResult(IPropertyBag2_Write_Proxy(pPropBag, 1, aBag(0), CSng(lQuality) / 100!)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapFrameEncode_Initialize_Proxy(pFrame, pPropBag)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapFrameEncode_SetSize_Proxy(pFrame, lWidth, lHeight)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapFrameEncode_WriteSource_Proxy(pFrame, pBitmap, ByVal 0)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapFrameEncode_Commit_Proxy(pFrame)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapEncoder_Commit_Proxy(pEncoder)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IStream_Size(pStream, cSize)) < 0 Then
        GoTo QH
    End If
    cSize = cSize * 10000
    If pvCheckHResult(IStream_Reset(pStream)) < 0 Then
        GoTo QH
    End If
    If cSize > 0 Then
        ReDim baOutput(0 To cSize - 1) As Byte
        If pvCheckHResult(IStream_Read(pStream, baOutput(0), cSize)) < 0 Then
            GoTo QH
        End If
    Else
        baOutput = vbNullString
    End If
    '--- success
    WicConvertToJpeg = True
QH:
    Exit Function
EH:
    Debug.Print Err.Description
End Function

Private Function pvCheckHResult(ByVal hResult As Long) As Long
    If hResult < 0 Then
        Err.Raise hResult
    End If
    pvCheckHResult = pvCheckHResult
End Function

Here is the sample Form1 that exercises the WicConvertToJpeg function above

Option Explicit

Private Declare Function DeleteFile Lib "kernel32" Alias "DeleteFileA" (ByVal lpFileName As String) As Long

Private Sub Form_Load()
    Dim lWidth          As Long
    Dim lHeight         As Long
    Dim baBitmap()      As Byte
    Dim baJpeg()        As Byte
    
    If Not WicLoadPicture("d:\temp\aaa.bmp", lWidth, lHeight, baBitmap) Then
        GoTo QH
    End If
    If Not WicConvertToJpeg(baJpeg, lWidth, lHeight, baBitmap, 80) Then
        GoTo QH
    End If
    WriteBinaryFile "d:\temp\aaa.jpg", baJpeg
QH:
End Sub

Public Sub WriteBinaryFile(sFile As String, baBuffer() As Byte)
    Dim nFile           As Integer
    
    Call DeleteFile(sFile)
    nFile = FreeFile
    Open sFile For Binary Access Write Shared As nFile
    If UBound(baBuffer) >= 0 Then
        Put nFile, , baBuffer
    End If
    Close nFile
End Sub

The test code above needs another .bas module with the WicLoadPicture function

Option Explicit

'--- WIC
Private Declare Function WICCreateImagingFactory_Proxy Lib "windowscodecs" (ByVal SDKVersion As Long, ppIImagingFactory As stdole.IUnknown) As Long
Private Declare Function IWICImagingFactory_CreateDecoderFromFilename_Proxy Lib "windowscodecs" (ByVal pFactory As stdole.IUnknown, ByVal wzFilename As Long, pguidVendor As Any, ByVal dwDesiredAccess As Long, ByVal lMetadataOptions As Long, ppIDecoder As stdole.IUnknown) As Long
Private Declare Function IWICImagingFactory_CreateFormatConverter_Proxy Lib "windowscodecs" (ByVal pFactory As stdole.IUnknown, ppIFormatConverter As stdole.IUnknown) As Long
Private Declare Function IWICBitmapDecoder_GetFrame_Proxy Lib "windowscodecs" (ByVal pThis As stdole.IUnknown, ByVal lIndex As Long, ppIBitmapFrame As stdole.IUnknown) As Long
Private Declare Function IWICBitmapSource_CopyPixels_Proxy Lib "windowscodecs" (ByVal pThis As stdole.IUnknown, prc As Any, ByVal cbStride As Long, ByVal cbBufferSize As Long, pbBuffer As Any) As Long
Private Declare Function IWICBitmapSource_GetSize_Proxy Lib "windowscodecs" (ByVal pThis As stdole.IUnknown, puiWidth As Long, puiHeight As Long) As Long
Private Declare Function IWICFormatConverter_Initialize_Proxy Lib "windowscodecs" (ByVal pThis As stdole.IUnknown, ByVal pISource As stdole.IUnknown, dstFormat As Any, ByVal lDither As Long, ByVal pIPalette As stdole.IUnknown, ByVal dblAlphaThresholdPercent As Double, ByVal lPaletteTranslate As Long) As Long

Private m_pWicFactory           As stdole.IUnknown

Public Function WicLoadPicture( _
            sFileName As String, _
            lWidth As Long, _
            lHeight As Long, _
            baOutput() As Byte) As Boolean
    Const WINCODEC_SDK_VERSION1 As Long = &H236&
    Const WINCODEC_SDK_VERSION2 As Long = &H237&
    Const GENERIC_READ          As Long = &H80000000
    Dim pDecoder        As stdole.IUnknown
    Dim pFrame          As stdole.IUnknown
    Dim pConverter      As stdole.IUnknown
    Dim aGUID(0 To 3)   As Long
    
    If m_pWicFactory Is Nothing Then
        If WICCreateImagingFactory_Proxy(WINCODEC_SDK_VERSION2, m_pWicFactory) < 0 Then
            If pvCheckHResult(WICCreateImagingFactory_Proxy(WINCODEC_SDK_VERSION1, m_pWicFactory)) < 0 Then
                GoTo QH
            End If
        End If
    End If
    If pvCheckHResult(IWICImagingFactory_CreateDecoderFromFilename_Proxy(m_pWicFactory, StrPtr(sFileName), ByVal 0, GENERIC_READ, 0, pDecoder)) < 0 Or pDecoder Is Nothing Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapDecoder_GetFrame_Proxy(pDecoder, 0, pFrame)) < 0 Or pFrame Is Nothing Then
        GoTo QH
    End If
    If pvCheckHResult(IWICBitmapSource_GetSize_Proxy(pFrame, lWidth, lHeight)) < 0 Then
        GoTo QH
    End If
    If pvCheckHResult(IWICImagingFactory_CreateFormatConverter_Proxy(m_pWicFactory, pConverter)) < 0 Or pConverter Is Nothing Then
        GoTo QH
    End If
    '--- GUID_WICPixelFormat32bppPBGRA
    aGUID(0) = &H6FDDC324
    aGUID(1) = &H4BFE4E03
    aGUID(2) = &H773D85B1
    aGUID(3) = &H10C98D76
    If pvCheckHResult(IWICFormatConverter_Initialize_Proxy(pConverter, pFrame, aGUID(0), 0, Nothing, 0#, 0)) < 0 Then
        GoTo QH
    End If
    ReDim baOutput(0 To lWidth * lHeight * 4 - 1) As Byte
    If pvCheckHResult(IWICBitmapSource_CopyPixels_Proxy(pConverter, ByVal 0&, lWidth * 4, lWidth * lHeight * 4, baOutput(0))) < 0 Then
        GoTo QH
    End If
    '--- success
    WicLoadPicture = True
QH:
End Function

Private Function pvCheckHResult(ByVal hResult As Long) As Long
    If hResult < 0 Then
        Err.Raise hResult
    End If
    pvCheckHResult = pvCheckHResult
End Function

Posted all this code with all API declares to be searchable in the forums as WIC is quite apocryphal technology here.

cheers,
</wqw>

[LeandroA]

Thanks for sharing, interesting! Do you have any opinion on comparing GDI + vs WIC?

[yereverluvinuncleber]

Well, one factor is that it requires Vista and above and so will not be compatible with NT5 devices, ie. Windows 2003, XP or ReactOS.

[wqweto]

Well, one factor is that it requires Vista and above and so will not be compatible with NT5 devices, ie. Windows 2003, XP or ReactOS.

A quote from Wikipedia: Windows Imaging Component (WIC) is a COM-based imaging codec framework introduced in Windows Vista (and later available in Windows XP Service Pack 3)[1] for working with and processing digital images and image metadata.

I'm currently aiming this code at a more recent OS version as I'm using DXGI Desktop Duplication (at Win8+ feature) along with the converter so yes, while GDI+ is available on XP and above and has a redist for Win2000 it seems WIC is available on Vista and above and has a redist for XP.

cheers,
</wqw>

[yereverluvinuncleber]

Interesting, do you have the link for the redist? It might be worth trying. Packaging a redistibutable with your program for the older oses might be problematic but for most developers, those oses won't be a primary target.

[xiaoyao]

CreateObject("WIA.ImageFile") ，Multiple image format conversion

Const wiaFormatBMP = "{B96B3CAB-0728-11D3-9D7B-0000F81EF32E}"
Const wiaFormatPNG = "{B96B3CAF-0728-11D3-9D7B-0000F81EF32E}"
Const wiaFormatGIF = "{B96B3CB0-0728-11D3-9D7B-0000F81EF32E}"
Const wiaFormatTIFF = "{B96B3CB1-0728-11D3-9D7B-0000F81EF32E}"
Const wiaFormatJPEG = "{B96B3CAE-0728-11D3-9D7B-0000F81EF32E}"

Sub WIA_Tojpg(srcFileName As String, JpgFile As String, Optional Quality As Long = 80)
' setup the image processor
Dim prc, img
Set prc = CreateObject("WIA.ImageProcess")
With prc.Filters
    .Add prc.FilterInfos("Convert").FilterID
    .Item(1).Properties("FormatID").Value = wiaFormatJPEG
    If Quality > 0 Then .Item(1).Properties("Quality").Value = Quality ' 100%
End With

' image object
Set img = CreateObject("WIA.ImageFile")
' load, process and save the file
img.LoadFile srcFileName
Set img = prc.Apply(img)
img.SaveFile JpgFile
End Sub
Sub TestWIA_PicTo()
    WIA_PicTo App.Path & "\002.bmp", App.Path & "\002_togif.gif", wiaFormatGIF, -1
End Sub
Sub WIA_PicTo(srcFileName As String, ToFile As String, Optional FormatID As String = wiaFormatJPEG, Optional Quality As Long = 80)
' setup the image processor
Dim prc, img
Set prc = CreateObject("WIA.ImageProcess")
With prc.Filters
    .Add prc.FilterInfos("Convert").FilterID
    .Item(1).Properties("FormatID").Value = FormatID
    If Quality > 0 Then .Item(1).Properties("Quality").Value = Quality ' 100%
End With

' image object
Set img = CreateObject("WIA.ImageFile")
' load, process and save the file
img.LoadFile srcFileName
Set img = prc.Apply(img)
img.SaveFile ToFile
End Sub

[xiaoyao]

Get Jpg Byte Array() by wia:

Function WIA_TojpgByte(srcFileName As String, JpgFile As String, Optional Quality As Long = 80) As Byte()
' setup the image processor
Dim prc As Object, img   As Object
Set prc = CreateObject("WIA.ImageProcess")
With prc.Filters
    .Add prc.FilterInfos("Convert").FilterID
    .Item(1).Properties("FormatID").Value = wiaFormatJPEG
    If Quality > 0 Then .Item(1).Properties("Quality").Value = Quality ' 100%
End With

' image object
Set img = CreateObject("WIA.ImageFile")
' load, process and save to byte Array
img.LoadFile srcFileName
Set img = prc.Apply(img)
'dim Bt() As Byte
'Bt = img.FileData.BinaryData()
WIA_TojpgByte = img.FileData.BinaryData()
End Function

test bmp 3840*2160(31.6MB)

used 84.4486 ms
WicLoadPicture("d:\temp\aaa.bmp", lWidth, lHeight, baBitmap) Then
WicConvertToJpeg
=============
WIA_Tojpg ,used 91.58 ms

gdiplus,used 96.18ms
get jpg byte from LoadPicture(BmpFile)

use loadfile (not LoadPicture),used 58.4ms
If GdipLoadImageFromFile(StrPtr(File1), lBitmap) = OK Then

[wqweto]

What are you measuring? Loading 31.6MB from HDD or from drive cache?

Please, stop micro-benchmarking *anything* because you don't know how to do it properly! I already told you several times these are bullsh*t elapsed times in milliseconds you are throwing left and right. . .

cheers,
</wqw>

[xiaoyao]

What are you measuring? Loading 31.6MB from HDD or from drive cache?

Please, stop micro-benchmarking *anything* because you don't know how to do it properly! I already told you several times these are bullsh*t elapsed times in milliseconds you are throwing left and right. . .

cheers,
</wqw>

A picture taken from my computer desktop.This is just a simple test running speed, you can ignore it

[baka]

also, we can use the typelib from the trick instead of the WIC API (I think)
maybe I will look into it later, right now I dont need JPG, but could be that I want it in the future.
if so, I will convert it to be used together with the typelib.

its good that we start using WIC more, sure, as you say not fully compatible with XP and not working on older OS, but more and more people are leaving those systems and why not use something more recent?
the same we could say about direct2d/directx, so we will be stuck forever with GDI. so thank for sharing wqweto.

[Schmidt]

Please, stop micro-benchmarking *anything* because you don't know how to do it properly!

I agree of course (with the part of "not knowing how to do it properly").

Though have to say, that I had high hopes, that WIC somehow incorporates the GPU now for JPG-encoding (on modern OSes) -
but at least on my machine (Win10 with both, an Intel- and an NVidia-GPU) the results are not as good as the ones from libJPGTurbo.

To encode a "Full HD" (1920x1080) 32bpp Bitmap (a ScreenShot) with 85% quality:
- libJpgTurbo is needing 7-8msec
- WIC needs nearly about 3 times as long -> 22-23msec

So there seems to be no GPU-accelerated JpgEncoding involved when using WIC -
and if we consider, that in a "RemoteServer-VNC-scenario", the Host (where the JPG-encoding takes place),
runs often "headless" (in a VM), then WIC using GPU-accellerated JPG-encoding becomes even more unlikely.

Here is my TestCode (using the somewhat newer libJPGTurbo-version, RC6 binds to):

Option Explicit

Private Src32bpp As cCairoSurface, JpgBuf() As Byte

Private Sub Form_Load()
  ReDim JpgBuf(0 To 10000000) 'ensure ~10MB "global JPG-BufSpace" for libJpgTurbo
  Set Src32bpp = Cairo.CreateSurface(0, 0, , "c:\temp\ScreenShot.png")
  Debug.Print New_c.FSO.FileLen("c:\temp\ScreenShot.png")
End Sub

Private Sub Form_Click()
  Cls
  Dim JPG As cJPG, JpgByteLen As Long, BOut() As Byte
  
  '**** libJPGTurbo-based encoding
  Set JPG = New_c.JPG
  
  New_c.Timing True
    With Src32bpp
         JpgByteLen = JPG.EncodeJPG(.DataPtr, .Width, .Height, VarPtr(JpgBuf(0)), 32, False, False, 85, TJ_420)
         'not really needed (when the result would be send via sockets directly from VarPtr(JpgBuf(0)),
         'but I'm including this here in the timing to isolate the Result-JpgBytes in their own ByteArray
         If JpgByteLen Then
            ReDim BOut(0 To JpgByteLen - 1)
            New_c.MemCopy VarPtr(BOut(0)), VarPtr(JpgBuf(0)), JpgByteLen
         End If
    End With
  Print JpgByteLen & New_c.Timing
  
  
  '**** WIC-based JPG-encoding
  Dim BInp() As Byte 'Let's leave the Input-ByteArray-prep out of the WIC-timing here
  ReDim BInp(0 To Src32bpp.Stride * Src32bpp.Height - 1)
  New_c.MemCopy VarPtr(BInp(0)), Src32bpp.DataPtr, Src32bpp.Stride * Src32bpp.Height
  Erase BOut
  
  New_c.Timing True
    With Src32bpp
         JpgByteLen = 0
         If WicConvertToJpeg(BOut, .Width, .Height, BInp, 85) Then JpgByteLen = UBound(BOut) + 1
    End With
  Print JpgByteLen & New_c.Timing
End Sub

Olaf

[wqweto]

Yes, libjpeg-turbo is a beast of an encoder! Everyone should donate $100 to not let the main contributor despair :-)) The funniest part is that it's a spin-off from the TurboVNC project -- its the SIMD optimized implementation of the JPEG compresor/decompressor they use and which was recently accepted as *the* reference JPEG implementation by the standard's committee thanks to its popularity.

But your generous "~10MB global JPG-BufSpace for libJpgTurbo" comment reminded me there is a SHCreateMemStream call on every iteration on every tile of every frame being encoded so I had to bite the bullet and implement IStream::Seek with DispCallByVtbl to be able to determine stream's currently used space instead of depending on its allocated space which IStream_Size API call returns. This I hope saves a couple of million stream object instantiations and even more underlying buffer reallocations overall for the linked VNC server effort.

cheers,
</wqw>

[Argus19]

Unfortunately, due to lack of knowledge of the English language, I could not find out if it is possible to get the playing time of animated .gifs using the WIC functions?

[georgekar]

One VB class for jpg:
https://github.com/M2000Interpreter/...main/cJpeg.cls
Try this

[xiaoyao]

how to resize image size by wia?

this only cut part of image,need your help,thanks
i want change file to jpg/png ,and resize it
if can cut any part of image,that's more better
img size:700*500
cut left=0,top=0, width=200,height=300
cut left=100,top=100,width=300,height=400

or cut first ,and resize 300*400 to 150*200 or resize to 150*350?

    If NewWidth <> lWidth Or NewHeight <> lHeight Then
        If pvCheckHResult(IWICBitmapFrameEncode_SetSize_Proxy(pFrame, NewWidth, NewHeight)) < 0 Then
            GoTo QH
        End If
    End If

Do wia and wic use the same API at the bottom? Perhaps they are all packaged in GDIPLUS?

[xiaoyao]

Is there any way to create a motion tween like flash?For example, 12 pictures are generated every second.
Suppose there is a background picture. Then draw a light bulb on it. The light bulb is slowly getting bigger. Before each painting. The corresponding part of the background picture should be drawn again.
For example, give him a reversal of the last transparent light bulb picture, which is to cover him with the original background picture. Or a mask map. ?

[Arnoutdv]

Maybe this discussion can enlighten you
https://graphicdesign.stackexchange....way-flash-does