Saving picture in VB6
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From: Bu on 15 Oct 2006 15:04 Hello, In VB6 you can save a picture, image or drawing with SavePicture Picture1.Image. This saves an image in .BMP-format which is very large. Is there a way to save this image in an .JPG format or other format that produces smaller files? N.B. The picture i want to sve is very simple (graph with just a few colours) Bu
From: Mike Williams on 15 Oct 2006 15:52 Bu wrote: > In VB6 you can save a picture, image or drawing with > SavePicture Picture1.Image. This saves an image in > .BMP-format which is very large. Is there a way to save > this image in an .JPG format or other format that > produces smaller files? N.B. The picture i want to > save is very simple (graph with just a few colours) Did you draw this picture yourself in VB, using the various VB drawing methods (Line, Circle, print, etc)? If so then it looks like the metafile or enhanced metafile format will be the most suitable (.wmf or ..emf). These produce a very small file size for drawing of the type you have mentioned. You can draw your picture directly to a metafile and / or to a Picture Box as well and you can then save the metafile to disk and it will open in almost any application that handles graphic files. The big advantage of such files is that they can be drawn into any device (a printer for example) using the full available resolution of that device. Otherwise, if you want a general purpose solution for saving images of various kinds then jpg is probably the way to go. There are many free bitmap to jpeg converters available for use in VB6. Various other options are also available. Post again with more details. Mike
From: Bu on 16 Oct 2006 13:42 On 15 Oct 2006 12:52:21 -0700, "Mike Williams" <gagamomo(a)yahoo.co.uk> wrote: > >Bu wrote: > >> In VB6 you can save a picture, image or drawing with >> SavePicture Picture1.Image. This saves an image in >> .BMP-format which is very large. Is there a way to save >> this image in an .JPG format or other format that >> produces smaller files? N.B. The picture i want to >> save is very simple (graph with just a few colours) > >Did you draw this picture yourself in VB, using the various VB drawing >methods (Line, Circle, print, etc)? If so then it looks like the >metafile or enhanced metafile format will be the most suitable (.wmf or >.emf). These produce a very small file size for drawing of the type you >have mentioned. You can draw your picture directly to a metafile and / >or to a Picture Box as well and you can then save the metafile to disk >and it will open in almost any application that handles graphic files. >The big advantage of such files is that they can be drawn into any >device (a printer for example) using the full available resolution of >that device. Otherwise, if you want a general purpose solution for >saving images of various kinds then jpg is probably the way to go. >There are many free bitmap to jpeg converters available for use in VB6. >Various other options are also available. Post again with more details. > >Mike Hi Mike, Thanks for your response. Yes i am 'drawing' a picture with mainly the commands 'Picture1.Line' or 'Picture1.Pset'. Actual i am drawing a kind of x-y graph (or x-T graph). I like to know a VB6-command that stores the result directly as an JPG- or GIF-file (or other general purpose small format file). Ofcourse i can convert later the file from bmp to jpg with a conversion program but i prefer however to save the picture directly from the VB program in the required format. I hope you or anybody else has any suggestions. Bu
From: Günter Grodotzki on 16 Oct 2006 16:24 Am Mon, 16 Oct 2006 19:42:45 +0200 schrieb Bu: > Hi Mike, > Thanks for your response. > Yes i am 'drawing' a picture with mainly the commands 'Picture1.Line' > or 'Picture1.Pset'. Actual i am drawing a kind of x-y graph (or x-T > graph). > I like to know a VB6-command that stores the result directly as an > JPG- or GIF-file (or other general purpose small format file). > Ofcourse i can convert later the file from bmp to jpg with a > conversion program but i prefer however to save the picture directly > from the VB program in the required format. > I hope you or anybody else has any suggestions. > > Bu afaik its not possible. you have to use a ocx/dll (either write one or use available). but this is very easy to use.
From: Mike Williams on 16 Oct 2006 16:47
"Bu" <si(a)si.si> wrote in message news:a9g7j29pvdl5ld1omjou9ag3bl8mrinim0(a)4ax.com... > Yes i am 'drawing' a picture with mainly the commands > 'Picture1.Line' or 'Picture1.Pset'. Actual i am drawing > a kind of x-y graph (or x-T graph). I like to know a VB6 > -command that stores the result directly as an JPG- or > GIF-file (or other general purpose small format file). Well, it's not actually so straight forward as simply having a "command" that will perform this job for you. VB6 just doesn't provide such functions. You can however write code to perform those tasks, and there are some nice examples on various VB programming sites. The first thing you need to do is to decide on a suitable format. Most formats that compress picture data have advantages and limitations, and those that give the best compression usually "lose" some of the original data in order to achieve the quite large compression that some of them are capable of, and most of them have various strengths and weaknesses. In your specific example, where you are dealing with an image that you are drawing yourself in code using the various Line and Pset and other standard VB drawing functions you would probably be better off using the metafile format. Essentially a metafile is a "list" of drawing instructions (often compiled into a file) that tell the viewer program how to perform the required drawing, and most graphic programs that you'll find in Windows understand that format, including Visual Basic. The big advantage with metafiles is that the completed file can be drawn into any suitable device (screen, printer or whatever) and it will use the full available pixels resolution of that device. Also, they usually have a very small file size. Visual Basic has a method for displaying a metafile (PaintPicture) or you can load such a metafile directly into the picture property of a picture box, but it does not have a method for creating them. One other little problem is that you need to create the metafile and then draw into it using its handle, which means you cannot use the VB printer object methods and must instead use the equivalent API drawing methods. These are quite simple to use though once you get used to them. Here is some very nice metafile code that was recently posted on one of the VB newsgroups (I think it was mpvbgd but I can't remember now who posted it). Create a new VB project and place a Comamnd Button on the Form and then paste in the following code. There are one or two very small points that needs ironing out in order for it to perform the precise job it is intended to do on the printed page, but other than that it performs extremely well and it will teach you a lot about both creating metafles and also using the API drawing routines. Check it out. Mike Option Explicit Private Type DOCINFO cbSize As Long sDocName As String sOutput As String sDatatype As String fwType As Long End Type Private Type RECT L As Long T As Long R As Long B As Long End Type Private Type LOGFONT lfHeight As Long lfWidth As Long lfEscapement As Long lfOrientation As Long lfWeight As Long LFItalic As Byte LFUnderline As Byte LFStrikeOut As Byte lfCharSet As Byte lfOutPrecision As Byte lfClipPrecision As Byte lfQuality As Byte lfPitchAndFamily As Byte lfFaceName As String * 32 End Type Const TA_BASELINE& = 24, TA_BOTTOM& = 8 Const TA_LEFT& = 0, TA_CENTER& = 6, TA_RIGHT& = 2 Private Declare Function GetEnhMetaFile& Lib "gdi32" _ Alias "GetEnhMetaFileA" (ByVal lpszMetaFile$) Private Declare Function CreateEnhMetaFile& Lib "gdi32" _ Alias "CreateEnhMetaFileA" (ByVal hdcRef&, _ ByVal FName$, Rct As RECT, ByVal D$) Private Declare Function CloseEnhMetaFile& Lib "gdi32" _ (ByVal hdc&) Private Declare Function DeleteEnhMetaFile& Lib "gdi32" _ (ByVal Hdl&) Private Declare Function PlayEnhMetaFile& Lib "gdi32" _ (ByVal hdc&, ByVal hemf&, lpRect As RECT) Private Declare Function Rectangle& Lib "gdi32" _ (ByVal hdc&, ByVal x1&, ByVal y1&, ByVal x2&, ByVal y2&) Private Declare Function Ellipse& Lib "gdi32" _ (ByVal hdc&, ByVal x1&, ByVal y1&, ByVal x2&, ByVal y2&) Private Declare Function SetStretchBltMode& Lib "gdi32" _ (ByVal hdc&, ByVal nStretchMode&) Private Declare Function SelectObject& Lib "gdi32" _ (ByVal hdc&, ByVal hObject&) Private Declare Function SetTextAlign& Lib "gdi32" _ (ByVal hdc&, ByVal wFlags&) Private Declare Function TextOut& Lib "gdi32" _ Alias "TextOutA" (ByVal hdc&, ByVal x&, ByVal y&, _ ByVal lpString$, ByVal nCount&) Private Declare Function SetBkMode& Lib "gdi32" _ (ByVal hdc&, ByVal nBkMode&) Private Declare Function CreateFontIndirect& _ Lib "gdi32" Alias "CreateFontIndirectA" _ (lpLogFont As LOGFONT) Private Declare Function DeleteObject& Lib "gdi32" _ (ByVal hObject&) Private Declare Function GetDeviceCaps& Lib "gdi32" _ (ByVal hdc&, ByVal nIndex&) Private Declare Function StartDoc& Lib "gdi32" _ Alias "StartDocA" (ByVal hdc&, lpdi As DOCINFO) Private Declare Function StartPage& Lib "gdi32" _ (ByVal hdc&) Private Declare Function EndDoc& Lib "gdi32" (ByVal hdc&) Private Declare Function EndPage& Lib "gdi32" (ByVal hdc&) Private dpMMX!, dpMMY! Private Sub Command1_Click() Dim MFDC&, MFHdl&, Rct As RECT, PixToHimetricX! Dim PixToHimetricY! 'define Metafile-Size (Himetric = 1/100 mm) Rct.R = 20000: Rct.B = 28200 'A4 with some Border 'generate Metafile-DC (compatible to the Printer-DC) 'directly on a File '(for drawing in Screen-Resolution use 0 instead 'of Printer.hdc) MFDC = CreateEnhMetaFile(Printer.hdc, "c:\test.emf", _ Rct, vbNullString) 'here we draw against the Metafile-DC DrawPrintOut MFDC 'closing the MF-DC generates an MF-Handle MFHdl = CloseEnhMetaFile(MFDC) 'delete Handle (File is not deleted) DeleteEnhMetaFile MFHdl MsgBox FileLen("c:\test.emf"), , "FileSize in Bytes" 'And now Read-Direction 'get the Handle ... MFHdl = GetEnhMetaFile("c:\test.emf") 'Play against the Picture-DC... Picture1.ScaleMode = vbPixels: Picture1.AutoRedraw = True Rct.R = Picture1.ScaleWidth: Rct.B = Picture1.ScaleHeight SetStretchBltMode hdc, 4 'HalfTone PlayEnhMetaFile Picture1.hdc, MFHdl, Rct Picture1.Refresh 'and here (possibly) against the printer If MsgBox("Should we print?", vbYes |