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dotnet sdk : wmf --> bmp background color
Hi;
I asked: 3) The rendered image has a black background. The metafile draws text, a box, and a line. But the metafile does not first fill the canvas with white. So the background starts off "empty." Question: 3) How do I have it start off with a background/fill of white instead of black? You said: 3) Call Graphics.FillRectangle to fill the bitmap first and then draw your image. My code is as follows: System.IO.MemoryStream mem = new System.IO.MemoryStream(); img.Save(mem, System.Drawing.Imaging.ImageFormat.get_Bmp()); I have no graphics context as this runs on the server and has no UI. How can I do a fill first? And even if I can, the bitmap generated has black for the background - it's not an alpha channel set to 100% transparent. So it would overwrite it anyways I believe. --
Hi
You try to test the code below. Since we draw a 400x400 wmf onto a 500x500 picture, it will has backcolor of White as we specified. Metafile mf = new Metafile(@"C:\Program Files\Microsoft Office\CLIPART\PUB60COR\AN01173_.WMF"); private const int szImg =500; private void button3_Click(object sender, System.EventArgs e) { Bitmap bmp = new Bitmap(szImg,szImg); Graphics g = Graphics.FromImage(bmp); SolidBrush sb = new SolidBrush(Color.White); g.FillRectangle(sb,0,0,szImg,szImg); g.DrawImage(mf,0,0,szImg-100,szImg-100); bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); } Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hi;
I won't be able to implement/test this till Monday but I think this gave me the solution to all of this. I assumed that since a Bitmap could be created with a metafile, that was the way to do it. The code you list here is a totally different way to get a metafile into a bitmap and it seems a logical way to do it. -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > You try to test the code below. > Since we draw a 400x400 wmf onto a 500x500 picture, it will has backcolor > of White as we specified. > Metafile mf = new Metafile(@"C:\Program Files\Microsoft > Office\CLIPART\PUB60COR\AN01173_.WMF"); > private const int szImg =500; > private void button3_Click(object sender, System.EventArgs e) > { > Bitmap bmp = new Bitmap(szImg,szImg); > Graphics g = Graphics.FromImage(bmp); > SolidBrush sb = new SolidBrush(Color.White); > g.FillRectangle(sb,0,0,szImg,szImg); > g.DrawImage(mf,0,0,szImg-100,szImg-100); > bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); > } > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
Thanks for your quickly reply! I look forward to hearing from your. Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hi;
Ok, this is working for emf/wmf except I do not want to have to use: SolidBrush sb = new SolidBrush(Color.White); g.FillRectangle(sb,0,0,szImg,szImg); Because I want the original bitmap to be empty - ie a 32-bit bitmap with alpha and the entire bitmap is 100% transparent to start. Then what I draw from the metafile will fill part of the bitmap, but the rest will remain transparent. Like a sprite in a game. How can I do this? -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > You try to test the code below. > Since we draw a 400x400 wmf onto a 500x500 picture, it will has backcolor > of White as we specified. > Metafile mf = new Metafile(@"C:\Program Files\Microsoft > Office\CLIPART\PUB60COR\AN01173_.WMF"); > private const int szImg =500; > private void button3_Click(object sender, System.EventArgs e) > { > Bitmap bmp = new Bitmap(szImg,szImg); > Graphics g = Graphics.FromImage(bmp); > SolidBrush sb = new SolidBrush(Color.White); > g.FillRectangle(sb,0,0,szImg,szImg); > g.DrawImage(mf,0,0,szImg-100,szImg-100); > bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); > } > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
There is no such a transparent bitmap, it should have the color(ARGB). In the Game program, the code is doing alpha blend all the time. e.g. Background Image(A) character Image(B), the sprite The game will keep rendering the A+B to generating C and show it. The C is the result Bitmap with A and B alpha blending. Of course, in Game programming they have special technique to make the render job fast. That is out of our topic. Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hi;
Yes I understand all of that. But how can I start with a bitmap that is 100% transparent? That link shows how to draw with alpha on top of a bitmap. Here is an example. Lets say I have a sprite in a video game. Parts of the bitmap are 100% transparent. So when I place the sprite on the game, the parts of the bitmap rectangle that are not the sprite show what is below it. How do I get an initial bitmap that is empty? -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > The transparent color is implemented via the Alpha blending. > That is to say we need to use code to control how picture A draw on Picture > B to implement the transparent (alpha blending). > Here is a link for your reference. > Alpha Blending Lines and Fills > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm > l/_gdiplus_alpha_blending_lines_and_fills_usecsharp.asp > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
The transparent color is implemented via the Alpha blending. That is to say we need to use code to control how picture A draw on Picture B to implement the transparent (alpha blending). Here is a link for your reference. Alpha Blending Lines and Fills http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm l/_gdiplus_alpha_blending_lines_and_fills_usecsharp.asp Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Right. But how do I create the character image B bitmap? That bitmap must
have pixels that are 100% clear. -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > There is no such a transparent bitmap, it should have the color(ARGB). > In the Game program, the code is doing alpha blend all the time. > e.g. > Background Image(A) > character Image(B), the sprite > > The game will keep rendering the A+B to generating C and show it. > The C is the result Bitmap with A and B alpha blending. > > Of course, in Game programming they have special technique to make the > render job fast. That is out of our topic. > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hello;
Maybe another way to ask the question is, I want to put a rectangular window in my bitmap so that rectangle is 100% transparent. How do I do that? -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > There is no such a transparent bitmap, it should have the color(ARGB). > In the Game program, the code is doing alpha blend all the time. > e.g. > Background Image(A) > character Image(B), the sprite > > The game will keep rendering the A+B to generating C and show it. > The C is the result Bitmap with A and B alpha blending. > > Of course, in Game programming they have special technique to make the > render job fast. That is out of our topic. > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
The code below will draw a 100% transparent rectangle onto the bmp.(You will see nothing) Bitmap bmp = new Bitmap(szImg,szImg); Graphics g = Graphics.FromImage(bmp); g.DrawImage(mf,0,0,szImg-100,szImg-100); Color cl = Color.FromArgb(0,0,0,0); //Color cl = Color.FromArgb(255,0,0,0);this way the rectangle can be seen Pen myPen = new Pen(cl,5); g.DrawRectangle(myPen,0,0,50,50); bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); there is no clear pixel, every pixel must has a RGB value(0<R,G,B<255) e.g. a color of (255,255,255) is black,(0,0,0) is white. Also I suggest take a look at a book about windows Graphics. e.g. Windows Graphics Programming: Win32 GDI and DirectDraw (With CD-ROM) (Hardcover) by Feng Yuan http://www.amazon.com/gp/product/0130869856/104-8670888-7842303?v=glance&n=2 83155&n=507846&s=books&v=glance Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hi
Thanks for your quick response. It seems that we need do low level gdi opertation to set the pixel of A=0. Also I find that you have a similar in the newsgroup below. Subject: Create metafile - bitmap with alpha Newsgroups: microsoft.public.win32.programmer.gdi Our colleague will follow you in that thread. Thanks for your understanding! Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hello;
I do have a bit of experience with graphics (I've done the graphics in a number of PC games). I would state it slightly different. Each pixel must have a specific ARGB value. And if a given pixel has A=0, then while it has an RGB value too, they are irrelevant. What I am trying to do is get a Bitmap object where the pixels in the bitmap have A=0. I then want to draw the metafile on that bitmap and the end result will be that the final bitmap will remain A=0 on pixels the metafile did not draw to. I tried your suggestion of: sb = new SolidBrush(Color.FromArgb(0, 0, 0, 255)); // blue so I see it if the alpha is off g.FillRectangle(sb, 0, 0, 10, 10); And that did not remove the underlying ARGB of (255, 255, 255, 255) - it was still black. I think the FillRectangle() writes that rectangle on top of what is already on the bitmap. As it has A=0, it basically is a NOP. So my question returns to, How can I get pixels in a Bitmap object to have A=0? There must be a way because otherwise you could not have non-rectangular bitmaps - like sprites in games, bubble help pop-ups, or rounded corners on windows. -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > The code below will draw a 100% transparent rectangle onto the bmp.(You > will see nothing) > Bitmap bmp = new Bitmap(szImg,szImg); > Graphics g = Graphics.FromImage(bmp); > g.DrawImage(mf,0,0,szImg-100,szImg-100); > Color cl = Color.FromArgb(0,0,0,0); > //Color cl = Color.FromArgb(255,0,0,0);this way the rectangle can be seen > Pen myPen = new Pen(cl,5); > g.DrawRectangle(myPen,0,0,50,50); > bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); > > there is no clear pixel, every pixel must has a RGB value(0<R,G,B<255) > e.g. a color of (255,255,255) is black,(0,0,0) is white. > > Also I suggest take a look at a book about windows Graphics. > e.g. > Windows Graphics Programming: Win32 GDI and DirectDraw (With CD-ROM) > (Hardcover) > by Feng Yuan > http://www.amazon.com/gp/product/0130869856/104-8670888-7842303?v=glance&n=2 > 83155&n=507846&s=books&v=glance > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
Based on my research, that need to read/write the rawdata in the Bitmap and I am not very familar with GDI issue. I think that may need consult the GDI/GDI+ API to do that. You may try to post it the newsgroup below, and that is why I suggest post in the gdi newsgroup. Newsgroups: microsoft.public.win32.programmer.gdi Thanks! Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hello;
That thread was a very different question - it was how to take a bitmap with alpha pixels (what I am trying to learn here) and place that in a metafile. So my question remains, how can I get pixels in a Bitmap object to have A=0? There must be a way because otherwise you could not have non-rectangular bitmaps - like sprites in games, bubble help pop-ups, or rounded corners on windows. -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > Thanks for your quick response. > It seems that we need do low level gdi opertation to set the pixel of A=0. > Also I find that you have a similar in the newsgroup below. > Subject: Create metafile - bitmap with alpha > Newsgroups: microsoft.public.win32.programmer.gdi > > Our colleague will follow you in that thread. > Thanks for your understanding! > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Would you please ask the development team how can I get pixels in a Bitmap
object to have A=0? There must be a way because otherwise you could not have non-rectangular bitmaps - like sprites in games, bubble help pop-ups, or rounded corners on windows. -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > Based on my research, that need to read/write the rawdata in the Bitmap and > I am not very familar with GDI issue. > I think that may need consult the GDI/GDI+ API to do that. > You may try to post it the newsgroup below, and that is why I suggest post > in the gdi newsgroup. > Newsgroups: microsoft.public.win32.programmer.gdi > > Thanks! > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hello;
I am trying to set A=0 form managed code. Would you please ask the .net development group how to do this to a Bitmap object? There must be a way to do this. -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > Thanks for your quickly reply! > Based on my knowledge, I think that is GDI issue, due to our process, the > gdi newsgroup is the right place you need to consult. > If you have any other concern about .NET framework, please feel free to > post here. > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
Thanks for your quickly reply! Based on my knowledge, I think that is GDI issue, due to our process, the gdi newsgroup is the right place you need to consult. If you have any other concern about .NET framework, please feel free to post here. Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
thank you - dave
[quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > I will forward your concern. > Thanks! > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
I will forward your concern. Thanks! Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
Hi
Based on my research, we need to use the code below to read/write the BitmapData directly. private void button3_Click(object sender, System.EventArgs e) { Bitmap bmp = new Bitmap(szImg,szImg,PixelFormat.Format32bppArgb); Graphics g = Graphics.FromImage(bmp); SolidBrush sb = new SolidBrush(Color.White); g.FillRectangle(sb,0,0,szImg,szImg); sb=new SolidBrush(Color.Blue); g.FillRectangle(sb,0,0,szImg-100,szImg-100); BitmapData bd = bmp.LockBits(new Rectangle(10,10,100,100),ImageLockMode.ReadWrite,bmp.PixelFormat); for(int y=0;y<bd.Height;y++) for(int x=0;x<bd.Width;x++) { Marshal.WriteByte(bd.Scan0,(bd.Stride*y)+(4*x),0); } bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); } Using the LockBits method to access image data http://www.bobpowell.net/lockingbits.htm AsI said before I am not familar with Bitmap, I am sorry for that. Also I think for .NET Drawing issue, you may post in the newsgropu below. That is the newsgroup discussed according class under System.Drawing. microsoft.public.dotnet.framework.drawing Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
ok, will try, thanks.
Also, no dotnet.framework.drawing in the managed newsgroups... -- thanks - dave [quoted text, click to view] ""Peter Huang" [MSFT]" wrote:
> Hi > > Based on my research, we need to use the code below to read/write the > BitmapData directly. > private void button3_Click(object sender, System.EventArgs e) > { > Bitmap bmp = new Bitmap(szImg,szImg,PixelFormat.Format32bppArgb); > Graphics g = Graphics.FromImage(bmp); > SolidBrush sb = new SolidBrush(Color.White); > g.FillRectangle(sb,0,0,szImg,szImg); > sb=new SolidBrush(Color.Blue); > g.FillRectangle(sb,0,0,szImg-100,szImg-100); > BitmapData bd = bmp.LockBits(new > Rectangle(10,10,100,100),ImageLockMode.ReadWrite,bmp.PixelFormat); > for(int y=0;y<bd.Height;y++) > for(int x=0;x<bd.Width;x++) > { > Marshal.WriteByte(bd.Scan0,(bd.Stride*y)+(4*x),0); > } > bmp.Save(@"C:\Temp\DesImg.bmp",ImageFormat.Bmp); > } > > Using the LockBits method to access image data > http://www.bobpowell.net/lockingbits.htm > > AsI said before I am not familar with Bitmap, I am sorry for that. > Also I think for .NET Drawing issue, you may post in the newsgropu below. > That is the newsgroup discussed according class under System.Drawing. > microsoft.public.dotnet.framework.drawing > > Best regards, > > Peter Huang > Microsoft Online Partner Support > > Get Secure! - www.microsoft.com/security > This posting is provided "AS IS" with no warranties, and confers no rights. >
Hi
Thanks for your feedback. So far the managed newsgroup did not cover all the microsoft public newsgroup. Best regards, Peter Huang Microsoft Online Partner Support Get Secure! - www.microsoft.com/security This posting is provided "AS IS" with no warranties, and confers no rights.
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