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Save Image In database(SQlite)[Resolved]
Posted: Thu Dec 08, 2016 2:01 pm
by collectordave
Hi all,
I have a need to store images in a database.
I can allready do that by using include binary getting address and length from the include. However i would like the user to select an image from disc and have that saved to the database.
So the question is after using LoadImage(0 how do i get the start address and length of the buffer in which the image is placed?
Maybe a dumb question?
Regards
cd
Re: Save Image In database
Posted: Thu Dec 08, 2016 2:26 pm
by collectordave
May Have cracked it.
Cobbled together some bits from the forum and came up with this:-
Code: Select all
UsePNGImageDecoder()
Structure ImageData
*address
size.i
EndStructure
LoadImage(0,"Afghanistan.png")
StartDrawing( ImageOutput(0) )
*imagedata.ImageData = AllocateMemory( SizeOf( ImageData ) )
With *imagedata
\address = DrawingBuffer()
\size = DrawingBufferPitch() * ImageHeight(0)
EndWith
Debug *imagedata\address
Debug *imagedata\size
StopDrawing()
seems to be giving me the right answers will put it into some more code to check fully and repost.
regards
cd
Re: Save Image In database
Posted: Thu Dec 08, 2016 2:53 pm
by srod
Well, unless you want to display the image for example, you could simply read the image file into a memory buffer with the memory and file functions and then dump it into a blob field in your database. That works fine. Retrieving the image is then just as straight forward.
Re: Save Image In database
Posted: Thu Dec 08, 2016 3:11 pm
by collectordave
Thanks srod
just tried this to load a .png image:-
Code: Select all
UsePNGImageDecoder()
file$ = OpenFileRequester("Select a file","","Text (.txt)|*.txt|All files (*.*)|*.*",0)
If file$
If ReadFile(0, file$)
length = Lof(0) ; get the length of opened file
*MemoryID = AllocateMemory(length) ; allocate the needed memory
If *MemoryID
bytes = ReadData(0, *MemoryID, length) ; read all data into the memory block
Debug "Number of bytes read: " + Str(bytes)
EndIf
CloseFile(0)
EndIf
EndIf
;SetDatabaseBlob(DBID, 0, *MemoryID, length)
Debug CatchImage(1, *MemoryID, length)
wFlags = #PB_Window_SystemMenu | #PB_Window_ScreenCentered
OpenWindow(#PB_Any, 0, 0, 320, 390, "Database Example", wFlags)
img1 = ImageGadget(#PB_Any, 10, 10, 300, 300, 0)
SetGadgetState(img1, ImageID(1))
Repeat
Select WaitWindowEvent()
Case #PB_Event_CloseWindow
appQuit = 1
EndSelect
Until appQuit = 1
and it worked first time. Used catchimage instead of setdatabaseblob but hopefully that will work I will know in an hour or two.
Are there any dangers in doing it this way? Does the memory need to be freed?
Regards
cd
Re: Save Image In database
Posted: Thu Dec 08, 2016 3:25 pm
by srod
After you have used CatchImage() then you can free the memory buffer you saved the image into. Similar deal when retrieving blobs from your database.
Re: Save Image In database
Posted: Thu Dec 08, 2016 4:42 pm
by collectordave
Hi All
think i have everything now. Saving loading and displaying images to an SQlite database code below hopefully not too many errors:-
Code: Select all
UseSQLiteDatabase()
UsePNGImageDecoder()
Enumeration FormWindow
#WinImgToDB
EndEnumeration
Enumeration FormGadget
#btnLoadImage
#strImageFileName
#img0
#btnSaveImage
#img1
#btnGetImage
#DBID
EndEnumeration
Global ImageFilename.s = ""
Macro FileExists(filename)
Bool(FileSize(fileName) > -1)
EndMacro
Procedure CreateDB()
If CreateFile(0, "Images.db")
CloseFile(0)
If OpenDatabase(#DBID, "Images.db", "", "")
DatabaseUpdate(#DBID, "CREATE TABLE [Images] ([Image] BLOB NULL); ")
CloseDatabase(#DBID)
EndIf
EndIf
EndProcedure
Procedure SaveImageToDB()
If Len(ImageFilename) > 0
If ReadFile(0, ImageFilename)
length = Lof(0) ; get the length of opened file
*MemoryID = AllocateMemory(length) ; allocate the needed memory
If *MemoryID
bytes = ReadData(0, *MemoryID, length) ; read all data into the memory block
Debug "Number of bytes read: " + Str(bytes)
EndIf
CloseFile(0)
EndIf
EndIf
If OpenDatabase(#DBID, "Images.db", "", "")
SetDatabaseBlob(#DBID, 0, *MemoryID, length)
queryString.s = "INSERT INTO Images (Image) values (?);"
DatabaseUpdate(#DBID, queryString)
CloseDatabase(#DBID)
FreeMemory(*MemoryID)
EndIf
EndProcedure
Procedure LoadImageFromFile()
ImageFilename = OpenFileRequester("Select an Image","","Image (.png)|*.png|All files (*.*)|*.*",0)
LoadImage(0,ImageFilename)
SetGadgetState(#img0, ImageID(0))
FreeImage(0)
EndProcedure
Procedure GetImageFromDB()
If OpenDatabase(#DBID, "Images.db", "", "")
If DatabaseQuery(#DBID, "SELECT * FROM Images;")
FirstDatabaseRow(#DBID)
pictureSize = DatabaseColumnSize(#DBID, 0)
*picture = AllocateMemory(pictureSize)
GetDatabaseBlob(#DBID, 0, *picture, pictureSize)
CatchImage(1, *picture, pictureSize)
SetGadgetState(#img1, ImageID(1))
FinishDatabaseQuery(#DBID)
FreeMemory(*picture)
EndIf
EndIf
EndProcedure
OpenWindow(#WinImgToDB, 0, 0, 550, 350, "", #PB_Window_SystemMenu)
ButtonGadget(#btnLoadImage, 460, 10, 80, 25, "Load Image")
StringGadget(#strImageFileName, 190, 10, 260, 25, "")
ImageGadget(#img0, 10, 10, 150, 150, 0, #PB_Image_Border)
ButtonGadget(#btnSaveImage, 170, 140, 80, 25, "Save Image")
ImageGadget(#img1, 10, 180, 150, 150, 0, #PB_Image_Border)
ButtonGadget(#btnGetImage, 170, 310, 80, 25, "Get Image")
If Not FileExists("Images.db")
CreateDB()
EndIf
Repeat
Event = WaitWindowEvent()
Select event
Case #PB_Event_CloseWindow
End
Case #PB_Event_Gadget
Select EventGadget()
Case #btnLoadImage
LoadImageFromFile()
Case #btnSaveImage
SaveImageToDB()
Case #btnGetImage
GetImageFromDB()
EndSelect
EndSelect
ForEver
Re: Save Image In database(SQlite)[Resolved]
Posted: Thu Dec 08, 2016 6:01 pm
by srod
Possible memory leak in the cases where the database cannot be opened.
To fix, replace the SaveImageToDB() procedure with :
Code: Select all
Procedure SaveImageToDB()
If Len(ImageFilename) > 0
If ReadFile(0, ImageFilename)
length = Lof(0) ; get the length of opened file
*MemoryID = AllocateMemory(length) ; allocate the needed memory
If *MemoryID
bytes = ReadData(0, *MemoryID, length) ; read all data into the memory block
Debug "Number of bytes read: " + Str(bytes)
If OpenDatabase(#DBID, "Images.db", "", "")
SetDatabaseBlob(#DBID, 0, *MemoryID, length)
queryString.s = "INSERT INTO Images (Image) values (?);"
DatabaseUpdate(#DBID, queryString)
CloseDatabase(#DBID)
EndIf
FreeMemory(*MemoryID)
EndIf
CloseFile(0)
EndIf
EndIf
EndProcedure
The important thing in avoiding the aforementioned leak is ensuring that the FreeMemory(*MemoryID) line is executed regardless of whether the DB can be opened or not which was not the case with your original function. In your function, if the OpenDatabase() function failed then the memory would not be freed (because of where you placed the FreeMemory() call.)
Re: Save Image In database(SQlite)[Resolved]
Posted: Fri Dec 09, 2016 6:16 am
by collectordave
Thanks srod
Can see that now you have pointed it out.
Cheers
cd
Re: Save Image In database(SQlite)[Resolved]
Posted: Mon Dec 12, 2016 8:21 pm
by collectordave
Hi
I know I have said resolved but just another question.
If ther user selects a rather large image is it possible to save a resized image to the database?
Basically reduce the size of the image to something manageable before saving to the database?
Regards
cd
Re: Save Image In database(SQlite)[Resolved]
Posted: Mon Dec 12, 2016 8:28 pm
by srod
You can load the image and then resize it with ResizeImage(). After this use EncodeImage() to save the image to memory and then off to an SQLite blob as before.
Alternatively, load the image, encode it to a memory buffer, compress the said buffer and then save to a blob.
Re: Save Image In database(SQlite)[Resolved]
Posted: Tue Dec 13, 2016 6:14 am
by collectordave
Works again thanks for the gentle push srod
cd