Extracting and displaying jpg pictures from a zip file.

[davido]

Can anyone help, please?

I have created a zip file containing some jpg pictures. That was easy.

I now wish to unpack these pictures to memory and then display them on a CanvasGadget.
Can anyone tell me the correct procedure to do this, please?

[Bisonte]

something like this ?

Code: Select all

UseJPEGImageDecoder()
UseZipPacker()

Procedure GetPackedImage(ArchivName.s, PictureName.s, PackPlugin = #PB_PackerPlugin_Zip)
  
  Protected Archiv, Size, *Buffer, Image
  
  If FileSize(ArchivName) > 0
    
    Archiv = OpenPack(#PB_Any, ArchivName, PackPlugin)
    
    If Archiv
      
      If ExaminePack(Archiv)
        
        While NextPackEntry(Archiv)
          
          If PackEntryName(Archiv) = PictureName
            
            Size = PackEntrySize(Archiv, #PB_Packer_UncompressedSize)
            *PictureBuffer = AllocateMemory(Size)
            
            If *PictureBuffer
              Result = UncompressPackMemory(Archiv, *PictureBuffer, Size, "abc.jpg")
              
              If Result = Size
                Image = CatchImage(#PB_Any, *PictureBuffer)
              EndIf  
              
              FreeMemory(*PictureBuffer)
              
            EndIf
          EndIf
          
        Wend
        
      EndIf
      
      ClosePack(Archiv)
      
    EndIf
    
  EndIf
  
  ProcedureReturn Image
  
EndProcedure

Image = GetPackedImage("d:\abc.zip","abc.jpg")

If IsImage(Image)
  Debug "Picture : "+Str(Image)
EndIf

If Not OpenWindow(0, 0, 0, 640, 480, "TestWindow", #PB_Window_SystemMenu|#PB_Window_ScreenCentered) : End : EndIf

CanvasGadget(0,0,0,640,480)

If StartDrawing(CanvasOutput(0))
  If IsImage(Image)
    DrawImage(ImageID(Image), 0, 0)
  EndIf
  StopDrawing()
EndIf
  
Repeat : Until WaitWindowEvent() = #PB_Event_CloseWindow

[JHPJHP]

If your using PureZip (PureBasic 5.11 - 32bit):

I don't think PureZip is ready for the latest Beta release... I was getting a CRC error...

Code: Select all

ZipFile.s = "C:\Users\Administrator\Desktop\test.zip"

If PureZIP_Archive_Read(ZipFile)
  UseJPEGImageDecoder()
  myFileinfo.PureZIP_FileInfo
  ReturnValue = PureZIP_Archive_FindFirst()
  
  While ReturnValue = #UNZ_OK
    PureZIP_Archive_FileInfo(@myFileinfo)
    
    If myFileinfo\unCompressedSize > 0
      *Buffer = AllocateMemory(myFileinfo\unCompressedSize)
      
      If *Buffer
        If PureZIP_Archive_ExtractMem(*Buffer, myFileinfo\unCompressedSize)
          If LCase(GetExtensionPart(myFileinfo\FileName)) = "jpg"
            ZipImage = CatchImage(#PB_Any, *Buffer, MemorySize(*Buffer))
            
            If IsImage(ZipImage)
              ;...
              
              FreeImage(ZipImage)
            EndIf
          EndIf
        EndIf
        FreeMemory(*Buffer)
      EndIf
    EndIf
    ReturnValue = PureZIP_Archive_FindNext()
  Wend
  PureZIP_Archive_Close()
EndIf

[falsam]

Another contribution (PB 5.20 Beta 10)

Code: Select all

EnableExplicit

Enumeration
  #ZipFile
  
  #Mainform
  #ListImg
  #Canvas
  #Image
EndEnumeration

Define.l Event, GEvent

Global WindowStyle.i=#PB_Window_MinimizeGadget|#PB_Window_MaximizeGadget|#PB_Window_ScreenCentered

Global ZipFile.s

Procedure ShowZipContent()
  Protected PackEntryName.s
  
  ZipFile = OpenFileRequester("Open file ...","", "zip files|*.zip", 0)

  If ZipFile <> ""
        
    OpenPack(#ZipFile, ZipFile, #PB_PackerPlugin_Zip)

    If ExaminePack(#ZipFile)
      While NextPackEntry(#ZipFile)
        
        PackEntryName = PackEntryName(#ZipFile)
      
        Select PackEntryType(#ZipFile)
      
          Case #PB_Packer_File
            AddGadgetItem(#ListImg, -1, PackEntryName)
                
        EndSelect
      Wend  
    EndIf
  EndIf
  
  ClosePack(#ZipFile)
EndProcedure


Procedure ShowImage(ImageName.s)
  Protected PackEntryName.s, ImageSize.i, *Image
  
  OpenPack(#ZipFile, ZipFile, #PB_PackerPlugin_Zip)
    
  ; Search entry name
  If ExaminePack(#ZipFile)
    While NextPackEntry(#ZipFile)
      
      PackEntryName = PackEntryName(#ZipFile)

      Select PackEntryType(#ZipFile)
        
        Case #PB_Packer_File
          If PackEntryName = ImageName
            ;Uncompress PackEntryName in memory 
            ImageSize = PackEntrySize(#ZipFile)
            *Image = AllocateMemory(ImageSize)
            UncompressPackMemory(#ZipFile, *Image, ImageSize)
    
          EndIf  
      EndSelect
    Wend  
  EndIf
      
  ClosePack(#ZipFile)
  
  ; Show image
  CatchImage(#Image, *Image, ImageSize)
    
  StartDrawing(CanvasOutput(#Canvas))
  DrawingMode(#PB_2DDrawing_Default)
  Box(0, 0, 370, 350) ;Canvas Clear
  DrawImage(ImageID(#Image), 0, 0)
  StopDrawing()
  
  FreeMemory(*Image)
  
EndProcedure

Procedure Open_MainForm()
  OpenWindow(#Mainform, 0, 0, 600, 400, "Unpack image in memory", WindowStyle)
  ListViewGadget(#ListImg, 10, 10, 200, 350)
  CanvasGadget(#Canvas, 220, 10, 370, 350)
EndProcedure

UseJPEGImageDecoder()
UsePNGImageDecoder()
UseTGAImageDecoder()

UseZipPacker()  
Open_MainForm()
ShowZipContent()

Repeat
  Event  = WaitWindowEvent(10)
  GEvent = EventGadget()
  
  Select Event
    Case #PB_Event_Gadget
      Select GEvent
          
        Case #ListImg
          ShowImage(GetGadgetItemText(#ListImg, GetGadgetState(#ListImg)))
          
      EndSelect
        
    Case #PB_Event_CloseWindow
      End
      
  EndSelect
ForEver

[davido]

@Bisonte
@JHPJHP
@falsam

Thank you all very much for you help, it is much appreciated.

It is a real privilege to be a member of this forum!

[TI-994A]

I now wish to unpack these pictures to memory and then display them on a CanvasGadget.

Hello davido. This one opens the zip file, enumerates the contents in a ListViewGadget(), and then displays the image that is selected from the list:

Code: Select all

InitNetwork()
UseZipPacker()
UseJPEGImageDecoder()

Enumeration
  #MainWindow
  #List
  #Image
  #Button
  #ZipFile
EndEnumeration

Procedure InitZip()
  If ReceiveHTTPFile("https://dl.dropboxusercontent.com/u/38177172/images.zip", 
                     GetTemporaryDirectory() + "images.zip")
    If OpenPack(#ZipFile, GetTemporaryDirectory() + "images.zip")
      AddGadgetItem(#List, -1, "file: images.zip")
      If ExaminePack(#ZipFile)
        While NextPackEntry(#ZipFile)
          AddGadgetItem(#List, -1, PackEntryName(#ZipFile))
        Wend
      EndIf
      ClosePack(#ZipFile)
    EndIf
  EndIf
EndProcedure

Procedure DisplayZipItem(fileNum)
  Protected zippedImage, *imageLoc, imageSize, files
  If OpenPack(#ZipFile, GetTemporaryDirectory() + "images.zip")
    If ExaminePack(#ZipFile)
      While NextPackEntry(#ZipFile)
        files + 1
        If files = fileNum
          imageSize = PackEntrySize(#ZipFile)
          *imageLoc = AllocateMemory(imageSize)
          UncompressPackMemory(#ZipFile, *imageLoc, imageSize)
          zippedImage = CatchImage(#PB_Any, *imageLoc, imageSize)
          SetGadgetState(#Image, ImageID(zippedImage))
          FreeMemory(*imageLoc)
        EndIf
      Wend
    EndIf
    ClosePack(#ZipFile)
  EndIf
EndProcedure

OpenWindow(#MainWindow, #PB_Any, #PB_Any, 220, 180, "Unzip & Display Images", 
           #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
ListViewGadget(#List, 10, 10, 100, 150)
ImageGadget(#Image, 120, 10, 85, 100, 0, #PB_Image_Raised)
InitZip()

Repeat
  Select WaitWindowEvent()
    Case #PB_Event_CloseWindow
      appQuit = 1
    Case #PB_Event_Gadget
      Select EventGadget()
        Case #List
          DisplayZipItem(GetGadgetState(#List))
      EndSelect
  EndSelect
Until appQuit

Hope you'll find it useful too.

[davido]

Hi TI-994A,

You're not the only one smiling!

Thank you very much for the lovely demonstration.

The cartoons were a very nice touch.

[TI-994A]

You're not the only one smiling!

Thank you for saying so!

On the whole, falsam's example is clearly more comprehensive. However, it seems to allocate memory based on the entire zip file size:

Code: Select all

FileLength = Lof(#Zipfile)  
*Image = AllocateMemory(FileLength)

I believe that it may be better to allocate only for the particular entry being used:

Code: Select all

imageSize = PackEntrySize(#ZipFile)
*imageLoc = AllocateMemory(imageSize)

Just a suggestion.

[falsam]

... However, it seems to allocate memory based on the entire zip file size ..... I believe that it may be better to allocate only for the particular entry being used.

TI-994A, you're right. I've updated the code.

PS : This code does not resize the image when displaying in canvasgadget.

[Fred]

Especially as the extracted zip item can be way larger than the zip file size, you have to use the uncompressed zip item size.