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Display PNG, JPG, etc. on Pocket PC

, 22 Sep 2002 CPOL
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Combine CXImage and DibSectionLite on Pocket PC.

Introduction

In doing quite a bit of work with a PocketPC home automation client, I needed a way to display user-defined images in the device.

I found some very good and useful code out there in CodeProject and was able to combine them (with some modifications and enhancements) into group of very useful libraries.

I won't go into too many details, as I've basically taken Chris Maunder's DibSectionLite and added methods to load using Davide Pizzolato's CXImage classes. You can find their original libraries and documentation on this site. No point in replicating it here.

Details

Most of the work was in taking the original CXImage library and modifying it to make it compile on the PocketPC (Using eVC 3.0) This required a few #define changes and #ifdef out any try...catch code. I opted to return false.

The next step was debugging the PNG code. Since the PNG library uses function pointers, it turns out that eVC modifies the signature between a debug and release build. The stack becomes corrupt upon return unless the signature for these functions are modified as below:

#if defined (_WIN32_WCE) && !defined (_DEBUG)
	#define _CDECL_MODE_	__cdecl
#else
	#define _CDECL_MODE_	
#endif

static void _CDECL_MODE_ user_write_data(png_structp png_ptr, 
                                         png_bytep data, 
                                         png_size_t length)
Finally, I modified DibSectionLite to include:
  • All the suggested fixes posted on CodeProject (including 16, 24 bit images)
  • Cropping. I have a floorplan image I need to pan around on the screen, cropping is quite fast when displaying only a portion of the image.
  • Original Load and Save now take a CFile or CString.. Useful for memory images (CMemFile)
  • Loading images via CXImage.

You can add support and shrink/expand you executable size based on these defines as well as the ones in CXImage:

#define DIBSECTION_SUPPORT_BMP 1
#define DIBSECTION_SUPPORT_GIF 1    // Patented! 
#define DIBSECTION_SUPPORT_JPG 1
#define DIBSECTION_SUPPORT_PNG 1
//#define DIBSECTION_SUPPORT_MNG 0  // Orig. Lib disabled this
#define DIBSECTION_SUPPORT_ICO 1
//#define DIBSECTION_SUPPORT_TIF 0  // Patented!   //too many problems with 
                                    // __cdecl, see header  //jk
#define DIBSECTION_SUPPORT_TGA 1
#define DIBSECTION_SUPPORT_PCX 1
//#define DIBSECTION_SUPPORT_WBMP 0 //totally corrupt image... This might 
                                    // take some work.  //jk 
//#define DIBSECTION_SUPPORT_WMF 0  // WMF and PocketPC don't go hand-in hand 
                                    // too well (GetEnhMetaFilePaletteEntries 
                                    // unsupported by the OS).
//#define DIBSECTION_SUPPORT_J2K 0  // Beta  //totally corrupt image... This 
                                    //might take some work. //jk
#define DIBSECTION_SUPPORT_JBG 1    // Patented! see ../jbig/patents.htm    

New methods for loading are as follows:
BOOL LoadPNG(LPCTSTR lpszFileName);
BOOL LoadJPG(LPCTSTR lpszFileName);
BOOL LoadBMP(LPCTSTR lpszFileName);
BOOL LoadGIF(LPCTSTR lpszFileName);
BOOL LoadMNG(LPCTSTR lpszFileName);
BOOL LoadICO(LPCTSTR lpszFileName);
BOOL LoadTIF(LPCTSTR lpszFileName);
BOOL LoadTGA(LPCTSTR lpszFileName);
BOOL LoadPCX(LPCTSTR lpszFileName);
BOOL LoadWBMP(LPCTSTR lpszFileName);
BOOL LoadWMF(LPCTSTR lpszFileName);
BOOL LoadJ2K(LPCTSTR lpszFileName);
BOOL LoadJBG(LPCTSTR lpszFileName);
The code unravels and builds as a bunch of .LIB

You can compile and build the PocketPCTest app for your device. It is nothing fancy. Simply an exerciser. Uncomment the line in PocketPCTestView.cpp as needed.

The test app includes a definition of:

CDIBSectionLite	m_image;
in the header.

To Draw:

void CPocketPCTestView::OnDraw(CDC* pDC)
{
	CPocketPCTestDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);

	// TODO: add draw code for native data here
	
	m_image.Draw(pDC, CPoint(0,0));

}
And to load:
CPocketPCTestView::CPocketPCTestView()
{
	// TODO: add construction code here

	m_image.LoadPNG(_T("\\test.png"));	// 24bit OK
//	m_image.LoadPNG(_T("\\test-pal.png"));	// 256 OK
//	m_image.LoadJPG(_T("\\test.JPG"));	//ok
//	m_image.LoadBMP(_T("\\test.BMP"));	//ok
//	m_image.LoadGIF(_T("\\test.GIF"));	//ok
//	m_image.LoadICO(_T("\\test.ICO"));	//ok
//	m_image.LoadTGA(_T("\\test.TGA"));	//ok
//	m_image.LoadPCX(_T("\\test.PCX"));	//ok
//	m_image.LoadJBG(_T("\\test.JBG"));	//ok
	
// This wasn't in the original code.
////	m_image.LoadMNG(_T("\\test.MNG"));	

// WMF and PocketPC don't go hand-in hand too well (GetEnhMetaFilePaletteEntries 
// unsupported by the OS).
////	m_image.LoadWMF(_T("\\test.WMF"));	

// too many problems with __cdecl, see header
////	m_image.LoadTIF(_T("\\test.TIF"));	

// totally corrupt image... This might take some work.
////	m_image.LoadWBMP(_T("\\test.WBMP"));

// totally corrupt image... This might take some work.
////	m_image.LoadJ2K(_T("\\test.J2K"));	

}
That's about it. I didn't really spend much time with making J2K, TIF, and WBMP work. I'll update the article if someone gets them working.

Chris and Davide, as well as those that have contributed to their articles. Many thanks! I hope some of these changes/fixes might make it back into your original libraries so us PocketPC developers can use your code 'out of the box'.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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About the Author

Jim Koornneef
Web Developer Golden Crater Corp
Canada Canada
Jim is the President of Golden Crater Corp. (formerly Golden Crater Software) which produces:
 
Tiny eBook Reader - Read eBooks anywhere, on any web enabled device or phone.
 
Doberman BMS - Home Automation and Building Management System bridging and enhancing several automation hardware platforms.

Comments and Discussions

 
GeneralI'm trying to compile it for PPC 2003 with VS2005 and get a lot of errors PinmemberWSQ11-Jul-10 22:50 
Generalit's complex、hard to use. and the autor didn't explain too much Pinmemberlanmanck6-Mar-09 4:19 
GeneralLinker error on building PocketPCTest PinmemberAvinash Sahay23-Apr-08 3:28 
GeneralDibSectionlite.cpp missing PinmemberAvinash Sahay23-Apr-08 2:37 
QuestionHow to display in a given window? PinmemberAvinash Sahay23-Apr-08 0:12 
AnswerRe: How to display in a given window? PinmemberAvinash Sahay23-Apr-08 0:32 
GeneralI am trying to compile it under evc4 Pinmemberxnkjljlj20-Jan-08 6:57 
GeneralI'm trying to compile it for PPC 2003 with VS2005 and get a lot of errors PinmemberOwenBurnett1-Jan-08 11:56 
GeneralTrying to compile under wince 4.2 PinmemberMember 282429318-Dec-07 5:54 
Generalneeded to add fclose on DIBSectionLite.cpp or else got file sharing error (open file handle) Pinmemberfatjimmy.com12-Apr-07 12:46 
Questionconvert .jpg to .bmp [modified] PinmemberC#_Smurf23-Jan-07 5:16 
GeneralCxImage Pocket PC Port [modified] PinmemberVincent_RICHOMME11-Apr-06 0:28 
GeneralRe: CxImage Pocket PC Port Pinmemberdmig1-Jun-06 5:59 
GeneralRe: CxImage Pocket PC Port PinmemberVincent_RICHOMME23-Aug-06 11:10 
GeneralRe: CxImage Pocket PC Port Pinmemberhchlqlz15-Oct-07 17:49 
GeneralRe: CxImage Pocket PC Port PinmemberVincent_RICHOMME16-Oct-07 0:06 
GeneralRe: CxImage Pocket PC Port Pinmemberyunf25-Nov-09 23:07 
GeneralCXImage PinmemberBertvR6-Mar-06 8:43 
GeneralI couldn't download the Source file Pinmembersmartslack15-Dec-05 0:30 
GeneraleVC++ with SP4 PinmemberAlper KARS23-Jun-05 23:53 
AnswerRe: eVC++ with SP4 PinmemberFabio Falsini28-Nov-05 5:33 
QuestionHow to load large JPG files? Pinmembercxf197629-Mar-05 21:43 
AnswerRe: How to load large JPG files? Pinmembercxf197629-Mar-05 21:45 
GeneralRe: How to load large JPG files? Pinmembercxf197629-Mar-05 23:17 
AnswerRe: How to load large JPG files? Pinmemberyangmingtao14-Mar-07 18:19 
QuestionHow to make alpha blending work for png files in wince? PinmemberDani1000013-Jan-05 14:18 
AnswerRe: How to make alpha blending work for png files in wince? PinmemberDani1000013-Jan-05 16:42 
QuestionHow to solve folowing link errors? PinmemberDani10000127-Dec-04 19:21 
GeneralEVC4 - a lot of problem Pinmemberlaputa12345622-Jul-04 16:59 
QuestionHow to load picture on button of ppc through eVB PinsussAnonymous7-Jul-04 21:42 
QuestionHow to synchronise the data btwn CDB & MDB PinsussAnonymous7-Jul-04 1:17 
Generalcustom icons for pocketpc development Pinsussanonymous5-Jul-04 3:32 
GeneralRe: custom icons for pocketpc development PinsussMarius Bugiulescu5-Jul-04 4:12 
GeneralCompression for a Tif PinmemberMr. Whipple21-Apr-04 11:50 
GeneralPrinting PinmemberJJK19-Mar-04 6:16 
GeneralStack Overflow problem Pinmember\SOLMAN2-Mar-04 0:17 
GeneralRe: Stack Overflow problem Pinmember\SOLMAN4-Mar-04 23:30 
GeneralRe: Stack Overflow problem Pinmembershuminglin6-Mar-04 6:25 
GeneralRe: Stack Overflow problem Pinmember\SOLMAN7-Mar-04 1:57 
GeneralRe: Stack Overflow problem Pinmembershuminglin7-Mar-04 6:31 
GeneralRe: Stack Overflow problem PinsussMarius Bugiulescu5-Jul-04 3:45 
GeneralRe: Stack Overflow problem PinmemberBaris ERGUN7-Dec-04 8:17 
Generalhave some questions to ask u ! Pinmemberdraker25-Nov-03 23:37 
GeneralMaking a free HBITMAP PinmemberThunder7714-Nov-03 7:04 
GeneralRe: Making a free HBITMAP PinmemberHemxluo1-Nov-05 23:42 
Generallink error Pinmemberwehaha6-Sep-03 22:15 
GeneralRe: link error PinmemberInfoEnable Corporation15-Oct-04 7:07 
GeneralRe: link error Pinmemberdancostin16-Jun-05 2:12 
Questionanyone ran it on ARM? Pinmemberakhella7-Jun-03 9:04 
AnswerRe: anyone ran it on ARM? Pinmember\SOLMAN11-Jun-03 4:30 

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