I am drawing bitmap images on graphics object using DrawImage method But the Images are in large number so it is taking too much time for Drawing. I have read in this forum that using StretchDIBits takes less time for Drawing.
I am scaling the image by calling Drawimage but i want any other efficent method.
I have a Vector of Bitmap* & i want to draw each Bitmap on graphics.
HDC orghDC = graphics.GetHDC();
CDC *dc = CDC::FromHandle(orghDC);
m_vImgFrames is image vector containg Bitmap*. I have taken HBITMAP from Bitmap*.
HBITMAP hBitmap;
m_vImgFrames[0]->GetHBITMAP(Color(255,0,0),&hBitmap);
Using this HBITMAP i want to draw on orghDC & finally on graphics. So I want to know how StretchDIBits can be used for scaling the Bitmap and finally draw on Graphics Object.
I am new to this forum.Any ideas or code can be helpful
Instead of using StretchDIBits, why not use the GDI+ API directly to scale the bitmap?:
CRect rc( 0, 0, 20, 30 );
graphics.DrawImage( (Image*)m_vImgFrames[0],
rc.left, rc.top, rc.Width(), rc.Height() );
To use StretchDIBits with Gdiplus::Bitmap you could do the following:
// get HBITMAP
HBITMAP hBitmap;
m_vImgFrames[0]->GetHBITMAP( Gdiplus::Color(), &hBitmap );
// get bits and additional info
BITMAP bmp = {};
::GetObject( hBitmap, sizeof(bmp), &bmp );
// prepare BITMAPINFO
BITMAPINFO bminfo = {};
bminfo.bmiHeader.biSize = sizeof( BITMAPINFO );
bminfo.bmiHeader.biWidth = bmp.bmWidth;
bminfo.bmiHeader.biHeight = bmp.bmHeight;
bminfo.bmiHeader.biBitCount = bmp.bmBitsPixel;
bminfo.bmiHeader.biCompression = BI_RGB;
bminfo.bmiHeader.biPlanes = bmp.bmPlanes;
bminfo.bmiHeader.biSizeImage = bmp.bmWidthBytes*bmp.bmHeight*4; // 4 stands for 32bpp
// select stretch mode
::SetStretchBltMode( HALFTONE );
// draw
::StretchDIBits( hDC, 0, 0, new_cx, new_cy, 0, 0,
m_vImgFrames[0]->GetWidth(), m_vImgFrames[0]->GetHeight(),
bmp.bmBits, &bminfo, DIB_RGB_COLORS, SRCCOPY );
But this doesn't looks much faster on my machine than simple Graphics::DrawImage.
Related
I'm trying to implement anti-aliasing in my MFC app, I'm using the technique described in this tutorial.
Create a bitmap (2x, 4x, 8x) the size of the original bitmap.
Draw on the resized bitmap (I'm only using simple figures (lines, circles and etc)).
Set StretchBlt Mode to HalfTone.
And Resize with StretchBlt to the original size.
Using this way, drawing in the resized bitmap it works, but I want to create a more generic function that receives a bitmap with the drawing already made and return with the anti-aliasing, I tried this:
static HBITMAP AntiAliasing(HBITMAP hBitmap)
{
int escala = 4;
HBITMAP bmp = __copia(hBitmap); // Copy the bitmap.
HDC hMemDC = CreateCompatibleDC(NULL);
HBITMAP bmpAntigo1 = (HBITMAP)::SelectObject(hMemDC, bmp);
BITMAP bitmap;
::GetObject(hBitmap, sizeof(BITMAP), &bitmap);
// Create a bitmap (2x, 4x, 8x) the size of the original bitmap.
HDC hDCDimensionado = ::CreateCompatibleDC(hMemDC);
HBITMAP bmpDimensionado = ::CreateCompatibleBitmap(hDCDimensionado,
bitmap.bmWidth * escala,
bitmap.bmHeight * escala);
HBITMAP hBmpVelho = (HBITMAP)::SelectObject(hDCDimensionado, bmpDimensionado);
// I also tried with {BLACKONWHITE, HALFTONE, WHITEONBLACK}
int oldStretchBltMode2 = ::SetStretchBltMode(hDCDimensionado, COLORONCOLOR);
// Resize the bitmap to the new size.
::StretchBlt(hDCDimensionado,
0, 0, bitmap.bmWidth * escala, bitmap.bmHeight * escala,
hMemDC,
0, 0, bitmap.bmWidth, bitmap.bmHeight,
SRCCOPY);
/*
* Here the bitmap has lost his colors and became black and white.
*/
::SetStretchBltMode(hDCDimensionado, oldStretchBltMode2);
// Set StretchBltMode to halfTone so can mimic the anti aliasing effect.
int oldStretchBltMode = ::SetStretchBltMode(hMemDC, HALFTONE);
// resize to the original size.
::StretchBlt(hMemDC,
0, 0, bitmap.bmWidth, bitmap.bmHeight,
hDCDimensionado,
0, 0, escala * bitmap.bmWidth, escala * bitmap.bmHeight,
SRCCOPY);
::SetStretchBltMode(hMemDC, oldStretchBltMode);
::SelectObject(hMemDC, bmpAntigo1);
::DeleteDC(hMemDC);
::SelectObject(hDCDimensionado, hBmpVelho);
DeleteDC(hDCDimensionado);
return bmp;
}
But this function doesn't work, the result loses its colors (all drawings became black) and there isn't anti aliasing.
Any help will be appreciated!
From documentation for CreateCompatibleBitmap:
Note: When a memory device context is created, it initially has a
1-by-1 monochrome bitmap selected into it. If this memory device
context is used in CreateCompatibleBitmap, the bitmap that is created
is a monochrome bitmap. To create a color bitmap, use the HDC that was
used to create the memory device context, as shown in the following
code:
Change the code and supply hdc for the desktop as show below:
HDC hdc = ::GetDC(0);
HBITMAP bmpDimensionado = ::CreateCompatibleBitmap(hdc, ...)
::ReleaseDC(0, hdc);
This will show the image, however this method will not produce the desired effect because it simply magnifies each pixel to larger size and reduces it back to the original pixel. There is no blending with neighboring pixels.
Use other methods such Direct2D with Gaussian blur effect, or use GDI+ instead with interpolation mode:
Gdiplus::GdiplusStartup...
void foo(HDC hdc)
{
Gdiplus::Bitmap bitmap(L"file.bmp");
if(bitmap.GetLastStatus() != 0)
return 0;
auto w = bitmap.GetWidth();
auto h = bitmap.GetHeight();
auto maxw = w * 2;
auto maxh = h * 2;
Gdiplus::Bitmap membmp(maxw, maxh);
Gdiplus::Graphics memgr(&membmp);
memgr.SetInterpolationMode(Gdiplus::InterpolationModeHighQualityBilinear);
memgr.DrawImage(&bitmap, 0, 0, maxw, maxh);
Gdiplus::Graphics gr(hdc);
gr.SetInterpolationMode(Gdiplus::InterpolationModeHighQualityBilinear);
gr.DrawImage(&membmp, 0, 0, w, h);
}
If target window is at least Vista, use GDI+ version 1.1 with blur effect. See also How to turn on GDI+ 1.1 in MFC project
#define GDIPVER 0x0110 //add this to precompiled header file
void blur(HDC hdc)
{
Gdiplus::Graphics graphics(hdc);
Gdiplus::Bitmap bitmap(L"file.bmp");
if(bitmap.GetLastStatus() != 0)
return;
Gdiplus::Blur blur;
Gdiplus::BlurParams blur_param;
blur_param.radius = 3; //change the radius for different result
blur_param.expandEdge = TRUE;
blur.SetParameters(&blur_param);
bitmap.ApplyEffect(&blur, NULL);
graphics.DrawImage(&bitmap, 0, 0);
}
I would like to do something which I believe is fairly simple but since I am new to the winapi I am finding a lot of problems. Basically I have an HDC (which I am BitBlitting from a loaded Bitmap) and I am drawing a rectangle on it. Then I would like to BitBlt that HDC onto a new HBITMAP Object, but alas for now to no avail.
Here is my code which I have been trying to get to work for a couple of hours now
BITMAPINFO info;
Bitmap *tempbmp = Bitmap::FromFile(L"C:\\Users\\abelajc\\Pictures\\BackgroundImage.png", false);
HBITMAP loadedbackground;
tempbmp->GetHBITMAP(NULL, &loadedbackground);
HBRUSH hRed = CreateSolidBrush(RGB(255, 0, 0));
HDC pDC = GetDC(0);
HDC TmpDC = CreateCompatibleDC(pDC); //main DC on which we will paint on
HDC dcBmp = CreateCompatibleDC(TmpDC); //DC for the loadedbackground HBitmap
HGDIOBJ TmpObj2 = SelectObject(dcBmp , tempbmp); //Selecting Bitmap in DC
BitBlt(TmpDC, 0, 0, 512, 512, dcBmp, 0, 0, SRCCOPY);
SelectObject(dcBmp, TmpObj2); //Deselecting Bitmap from DC
DeleteDC(dcBmp);
RECT rectangle;
SetRect(&rectangle, 5, 5, 20, 20);
FillRect(TmpDC, &rectangle, hRed);
HDC hCompDC = CreateCompatibleDC(TmpDC);
HBITMAP hBmp = CreateCompatibleBitmap(TmpDC, 512, 512);
HBITMAP hOld = (HBITMAP)SelectObject(hCompDC, hBmp);
BitBlt(hCompDC, 0, 0, 512, 512, TmpDC, 0, 0, SRCCOPY);
SelectObject(hCompDC, hOld);
DeleteDC(hCompDC);
Bitmap *image = new Bitmap(hBmp, NULL);
I think you just need some clarification about GDI.
A DC is exactly what its name imply : a device context. It's just a context, nothing concrete. Some DCs are context to a real graphic device, some others (memory DCs) are context to a virtual graphic surface in memory. The DCs you create with CreateCompatibleDC are memory DC, but creating the DC only create the context, not the memory surface. As the MSDN documentation says :
Before an application can use a memory DC for drawing operations, it must select a bitmap of the correct width and height into the DC.
You need to associate a HBITMAP with the DC. After doing that, you can consider that drawing to the DC is essentially drawing to the bitmap. The memory DC is the 'window' to the bitmap.
Once you understand that, you will see that your program can be greatly shortened. Feel free to comment if you still have problems.
Working in mingw, having a terrible time creating a color DC in memory. For instance, in the following code snippet, as written, "foo_scratch.bmp" is a monochrome version of the
image (from an EMR_STRETCHDIBITS record). If instead aDC is omitted and srcDC uses the CreateDC directly, then that file has a color image.
Gdiplus::Bitmap *pbmp = NULL;
BITMAPINFO *pbitmapinfo = (BITMAPINFO *)((char *)lpEMFR + pEmr->offBmiSrc);
void *pBitsInMem = (char *)lpEMFR + pEmr->offBitsSrc;
HBITMAP hbmsrc;
HDC aDC = CreateDC("DISPLAY", "", NULL, NULL);
HDC srcDC = CreateCompatibleDC(aDC);
hbmsrc = CreateDIBitmap(
srcDC,
&(pbitmapinfo->bmiHeader),
CBM_INIT,
pBitsInMem,
pbitmapinfo,
DIB_RGB_COLORS);
if(hbmsrc){
CLSID pngClsid;
GetEncoderClsid(L"image/bmp", &pngClsid);
pbmp = Gdiplus::Bitmap::FromHBITMAP(hbmsrc,NULL);
pbmp->Save(L"C:\\Temp\\foo_scratch.bmp",&pngClsid, NULL);
This all comes to a head later when two images (hbmdst, hbmsrc) need to be put together with a bitblt operation. At present the best I have managed is monochrome. At worst the image is solid black. In this snippet the ROP has been hard coded to SRCCOPY, and I still have not succeeded in just copying the image from one HBITMAP to another. Very frustrating!
HDC dstDC = CreateCompatibleDC(aDC);
HBITMAP hbmdOld = (HBITMAP) SelectObject(dstDC, hbmdst);
HBITMAP hbmsOld = (HBITMAP) SelectObject(srcDC, hbmsrc);
GetObject(hbmsrc, sizeof(bm), &bm);
BitBlt(dstDC, 0, 0, bm.bmWidth, bm.bmHeight, srcDC, 0, 0, SRCCOPY);
SelectObject(srcDC, hbmsOld);
SelectObject(dstDC, hbmdOld);
(void) DeleteDC(dstDC);
pbmp = Gdiplus::Bitmap::FromHBITMAP(hbmdst,NULL);
pbmp->Save(L"C:\\Temp\\scratch.bmp",&pngClsid, NULL);
What am I doing wrong?
Thanks
Figured it out - wherever a bitmap is created have to use the DC directly associated with the display (or other device), not the "compatible" DC derived from the first DC.
How to convert HICON to HBITMAP in VC++?
I know this is an FAQ but all the solutions I've found on Google don't work. What I need is a function which takes a parameter HICON and returns HBITMAP.
Greatest if possible to make conversion to 32-bit bitmap even the icon is 24-bit, 16-bit or 8-bit.
This is the code, I don't know where it goes wrong:
HBITMAP icon_to_bitmap(HICON Icon_Handle) {
HDC Screen_Handle = GetDC(NULL);
HDC Device_Handle = CreateCompatibleDC(Screen_Handle);
HBITMAP Bitmap_Handle =
CreateCompatibleBitmap(Device_Handle,GetSystemMetrics(SM_CXICON),
GetSystemMetrics(SM_CYICON));
HBITMAP Old_Bitmap = (HBITMAP)SelectObject(Device_Handle,Bitmap_Handle);
DrawIcon(Device_Handle, 0,0, Icon_Handle);
SelectObject(Device_Handle,Old_Bitmap);
DeleteDC(Device_Handle);
ReleaseDC(NULL,Screen_Handle);
return Bitmap_Handle;
}
this code do it:
HICON hIcon = (HICON)LoadImage(instance, MAKEINTRESOURCEW(IDI_ICON), IMAGE_ICON, width, height, 0);
ICONINFO iconinfo;
GetIconInfo(hIcon, &iconinfo);
HBITMAP hBitmap = iconinfo.hbmColor;
and this is the code in the *.rc file:
IDI_ICON ICON "example.ico"
and this is the code in the *.h file:
#define IDI_ICON 4000
HDC hDC = GetDC(NULL);
HDC hMemDC = CreateCompatibleDC(hDC);
HBITMAP hMemBmp = CreateCompatibleBitmap(hDC, x, y);
HBITMAP hResultBmp = NULL;
HGDIOBJ hOrgBMP = SelectObject(hMemDC, hMemBmp);
DrawIconEx(hMemDC, 0, 0, hIcon, x, y, 0, NULL, DI_NORMAL);
hResultBmp = hMemBmp;
hMemBmp = NULL;
SelectObject(hMemDC, hOrgBMP);
DeleteDC(hMemDC);
ReleaseDC(NULL, hDC);
DestroyIcon(hIcon);
return hResultBmp;
I don't have code readily available to share, but I think this is pretty easy. You have to create the HBITMAP, create a device context, select the bitmap into the DC (this will make the bitmap the drawing area for this DC). Finally call the DrawIcon() function to draw your icon on this DC. After that detach the bitmap from the DC and destroy the DC. Your bitmap now should be ready to go.
Update after looking at your code:
I believe the problem is in the createCompatibleBitmap call. You are asking for a bitmap compatible with the memory DC, but memory DCs start with a 1 bit/pixel bitmap selected into them. Try asking for a bitmap compatible with the screen DC instead.
Update 2: you may want to look at this question as it seems related to your problem.
I found this(similar code works for me - 32x32 icons with or without alpha data):
used CopyImage (msdn link)
HICON hICON = /*your code here*/
HBITMAP hBITMAPcopy;
ICONINFOEX IconInfo;
BITMAP BM_32_bit_color;
BITMAP BM_1_bit_mask;
// 1. From HICON to HBITMAP for color and mask separately
//.cbSize required
//memset((void*)&IconInfo, 0, sizeof(ICONINFOEX));
IconInfo.cbSize = sizeof(ICONINFOEX);
GetIconInfoEx( hICON , &IconInfo);
//HBITMAP IconInfo.hbmColor is 32bit per pxl, however alpha bytes can be zeroed or can be not.
//HBITMAP IconInfo.hbmMask is 1bit per pxl
// 2. From HBITMAP to BITMAP for color
// (HBITMAP without raw data -> HBITMAP with raw data)
// LR_CREATEDIBSECTION - DIB section will be created,
// so .bmBits pointer will not be null
hBITMAPcopy = (HBITMAP)CopyImage(IconInfo.hbmColor, IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);
// (HBITMAP to BITMAP)
GetObject(hBITMAPcopy, sizeof(BITMAP), &BM_32_bit_color);
//Now: BM_32_bit_color.bmBits pointing to BGRA data.(.bmWidth * .bmHeight * (.bmBitsPixel/8))
// 3. From HBITMAP to BITMAP for mask
hBITMAPcopy = (HBITMAP)CopyImage(IconInfo.hbmMask, IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);
GetObject(hBITMAPcopy, sizeof(BITMAP), &BM_1_bit_mask);
//Now: BM_1_bit_mask.bmBits pointing to mask data (.bmWidth * .bmHeight Bits!)
BM_32_bit_color bitmap may be have Alpha *channel*(each 4th byte) already set! So - check for it before u add mask bit to color data.
I'm trying to write a class to wrap bitmap functionality in my program.
One useful feature would be to copy a bitmap from another bitmap handle. I'm a bit stuck:
void operator=( MyBitmapType & bmp )
{
HDC dcMem;
HDC dcSource;
if( m_hBitmap != bmp.Handle() )
{
if( m_hBitmap )
this->DisposeOf();
// copy the bitmap header from the source bitmap
GetObject( bmp.Handle(), sizeof(BITMAP), (LPVOID)&m_bmpHeader );
// Create a compatible bitmap
dcMem = CreateCompatibleDC( NULL );
m_hBitmap = CreateCompatibleBitmap( dcMem, m_bmpHeader.bmWidth, m_bmpHeader.bmHeight );
// copy bitmap data
BitBlt( dcMem, 0, 0, bmp.Header().bmWidth, bmp.Header().bmHeight, dcSource, 0, 0, SRCCOPY );
}
}
This code is missing one thing: How can I get an HDC to the source bitmap if all I have of the source bitmap is a handle (e.g. an HBITMAP?)
You can see in the code above, I've used "dcSource" in the BitBlt() call. But I don't know how to get this dcSource from the source bitmap's handle (bmp.Handle() returns the source bitmaps handle)
You can't -- the source bitmap may not be selected into a DC at all, and even if it is you have no way to find out what DC.
To do your copy, you probably want to use something like:
dcSrc = CreateCompatibleDC(NULL);
SelectObject(dcSrc, bmp);
Then you can blit from the source to destination DC.
Worked for me:
// hBmp is a HBITMAP
HBITMAP hBmpCopy= (HBITMAP) CopyImage(hBmp, IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE);