Howdy folks, I am currently attempting to print a few thousand TIFF images, however, after ~1100 images I catch an exception saying, "Attempted to read or write protected memory...", or, "The handle is invalid". I am unable to continue printing until I restart the application and begin again. ...more >>

How do I load a 32bit ARGB formatted bitmap into an Image object? I tried this Image.FromFile(path) but apparently I am loosing the alpha channel. If I export (by a tool) the BMP to PNG and load that file alpha is actually preserved? Any hint (P/Invoke?) is appreciated. tb...more >>

Hi, I want to develop a windows based application using .Net 2.0 The application will have the heavy UI and it will have the lots of drawing to do on the form. So can any one give me the direction how can i handle the different issues that will arise in the same due to paint event and due...more >>

Is there any relatively simple way to rotate a bitmap (PixelFormat = Format8bppIndexed) by say, 9 degrees? Thanks! -sb ...more >>

I'd like to draw some GDI+ graphics on top of a web page in a windows form application, but I can't seem to do it. The WebBrowser control hides the Paint event (and never calls the OnPaint method); and putting a transparent other control on top doesn't work because "transparency" of a control...more >>

Since there's no decent built-in color quantization for the .Net gif encoder (really, who in the heck uses the web-safe palette anymore?), we have to do it ourselves. This page: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspp/html/colorquant.asp provides the code t...more >>

Hi, I'm trying to draw a metafile on top of another metafile using C# Express. I'm used to doing this with PlayEnhMetafile (and friends) in the Win32 API, using Delphi, but now I need to do the same in dotnet. The purpose is to see if a problem I have here is also present in dotnet, and ther...more >>

I am using VB.NET and I am capturing frames from a camera. Since the data is coming to my app via an array of bytes and is 8 bit, I am using the following code to display it in a picturebox. Private Sub ConvertFromArrayToPictureBox(ByRef oPixBox As PictureBox, ByVal arrByte() As Byte) Dim...more >>

I want to create a custom form (all drawn in the pain event) that is part solid (i.e. non see through) and part see through (e.g. 50% opacity). I've tried setting the BackColor and TransparanceKey colors to the same value and drawing lines with different Alpha color values. The lines with an A...more >>

Hello: In a test app that reproduces a requirement of another app, I am trying to load an image from disk into a System.Drawing.Image object, and then read the bytes of the image object into a memory stream. The code is as follows... Image img = null; using (FileStream fs = new FileStr...more >>

I found usefull way to draw arrows: http://groups.google.com/group/microsoft.public.dotnet.framework.drawing/browse_thread/thread/d909c2f68b245d25/6d5c2a8ccdb7f937?lnk=st&q=C%23+AdjustableArrowCap&rnum=1#6d5c2a8ccdb7f937 but I need to create kind of OnMouseDown on this arrows and don't know how...more >>

I created a BufferedGraphics object using the BufferedGraphicsContext->Allocate method, and I still get screen flicker. My paint method is simple enough: BufGraphics->Graphics->DrawImage(... BufGraphics->Graphics->DrawImage(... BufGraphics->Render(); When I use t...more >>

hi, is there a way using GDI+ to fill a line ,rectangle or any other group of pixels with colors, but specify the color of each pixel (the colors of the pixels can be different) ? thanks. ...more >>

Hi, How can I convert measurement in Pixel unit to Point unit? e.g., 10pixel = ? point Thanks. -- sync...more >>

Hi all! Am I correct if I say that saving bitmaps using bitmap.Save("filename", ImageFormat.Tiff); is actually saving the bitmap in a separate thread, and that the "filename" file is not ready for reading immediately after the next line of the app code is processed? I'm having one ap...more >>

I would like to understand the meaning of these colour descriptions e.g.#E7E7FF or #4A3C8C Is it RGB and how it is represented within these description? Also does anyone know of any article that explains how to guess the RGB for a specific destination colour Thank you, Samuel Shulman ...more >>

Hello all, I need to develop a small application that browses webpages automatically and saves the images found on those pages. Probably you would say: iterate the HtmlElements collection, find the value of the SRC attribute, load each image using its corresponding URL and then save it. Th...more >>

In my drawing code I recusrively create an average number of pens and brushes of, let's guess: 300? Would I see performance improvment by just caching those? (actually I use and create all of them in a using() statment) -- Regards, Lloyd Dupont NovaMind development team NovaMind Soft...more >>

Hi I just make some test to see the effect of PenAlignment. And I noticed that: * using Graphics.DrawLine: no effect, it is always "Center" * using Graphics.DrawRectangle: Center and Inset are ok but Left, Outset and Right are always "Center" * using Graphics.DrawPath: same as DrawLine ...more >>

Hello, How do I fill an irregular shape with a given color in an image with System.Drawing? Let's say I have a map of North America and I want to paint the USA with a color given by my user. It's just like doing a fill with paint or photoshop right in the middle of the USA. Is there a way ...more >>

Hi all, I have some trouble with the Graphics.DpiX / Y The value of DpiX and DpiY is the value configured in the "Display" configuration panel and is by default set to 96 dpi. So, my resolution is 1600x1200, I used a transformation and set pageunit to millimeters and then I draw a line ...more >>

Hi, I am writing a cheque (check) printing application, which draws the cheque on the front and back of a 6 X 2.5 dimension image. I have used a 2 frame tiff file (for front and back). For performance reasons I am creating a temp image file containing the basic cheque layout and trying t...more >>

Hi All, I'm doing a System.Drawing.Image.Save(filepath) but it gives me the error "A general error occured in GDI+". I did browse through many solutions but none worked. I'm doing this in the C# code that I'm writing to customize MS Word (COM Add-in). I even tried Bitmap.Save but it gives me th...more >>

I'm trying to draw a linear gradient between two colours using the LinearGradientBrush class. It sounds simple enough however I get a line of the second colour at the top of the gradient in certain situations. Placing the code below in the paint event of a Panel will hopefully demonstrate th...more >>

Hi, I want to ask about fast "clearing" image to transparency color. Something like: FillRect(Brushes.Transparent, 10, 20, 16, 16), but because all new pixels are transparent then... all will be ignored. Generally I have buffer (Bitmap) object. This buffer is divided on tiles. At any time I...more >>

Hi! I need to access the XMP-metadata stored by Photoshop in jpeg-files. I have been looking for a solution for hours on google, google groups etc et c Fields can be found here: http://www.portfoliofaq.com/pfaq/FAQ00311.htm And Adobe (who invented the format as far as I can tell) has create...more >>

The .NET class libary presents this as an example of GraphicsPath.IsVisible: Public Sub IsVisibleExample(ByVal e As PaintEventArgs) Dim myPath As New GraphicsPath myPath.AddEllipse(0, 0, 100, 100) Dim visible As Boolean = myPath.IsVisible(50, 50, e.Graphics) MessageBox.Show(...more >>

OnPaint I need to draw the text contents of lots of grid cells. For it to look right, each cell's contents cannot be rendered outside the bounding rectangle of the cell. Only, DrawString does not allow me to specify a bounnding rectangle. Do I really need to create a new Region for each cell, ...more >>

I have 1 bit CCITT 4 compressed TIFFS. I can save these efficiently, but as soon as I modify the image using the graphics drawstring method to stamp some text on the image, I have to convert the image to 1bit to get it to save back using the CCITT 4 compression. This operation takes severa...more >>

Hello I have built a DataGridView that its data source is binded to a DataTable after adding it 200 rows I try to remove the first row and the program stuck, What could it be???? Thanks. ...more >>

As part of a custom animation initiated by a control on a form, I would like to draw outside the boundaries of the control or even outside the boundaries of its containing form. I can't do this using CreateGraphics on either the control or its parent form, and I'm trying to stay away from usin...more >>

Hi All, I am tying to build a ASP.net 2.0 based web page which displays a Analog Guage ( 0 to 180 degrees) with an Arrow in the middle. The application accepts the Percentage as input from a text box and then generates an image which shows a Arrow pointer dipicting that percentage on ...more >>

I have created a program that displays different pictures on the form at the same time. When I have no ImageAttributes against the images, everything runs perfect and smooth. When I start adding ImageAttributes (greyscale, negative, etc) the program starts to slow down and lag. This is be...more >>

I have a bitmap drawn on my form and I wish to draw an ellipse over it using the bitmap colors inverted. I used to do this using GetDC() and SetROP2(). Is there a way to do something similar using a Graphics object? Regards Chris Saunders ...more >>

I have implemented Bob Powell's method for 1 bit conversions and am wondering if there is a faster way to do this? I am finding that in .NET 2.0 using this method, it is particularly slow. Have there been any improvements in the framework in 2.0 for dealing with images? Are there alternativ...more >>

Hi, I try to split multipage tif file to separate files using vb.net 2.0. To accomplish this I use the following code Dim sourceBitmapFile As New Bitmap("multiPageTiffFile") Dim saveCodecInfo As ImageCodecInfo = GetEncoderInfo("image/tiff") Dim saveEncoderParameters As New Encod...more >>

Hi Newsgroup, for a project at high school I need to superpose 12 grayscale bitmaps into one Bitmap. For each Point P(x,y) in the resulting bitmap the grayscale value should be the arithmetic mean of all P(x,y) of the 12 bitmaps: Pres(x,y) = (P1(x,y) + P2(x,y) + P3(x,y) + ... + P12(x,y)...more >>

Hi all, I'm looking at trying to improve the performance of showing a bunch of controls on a panel. I have a class that extends Panel. In that class, I do the following: this.SuspendLayout(); this.Hide(); //add controls to "this" AddControls(); this.ResumeLayout(); this.Show(); I hav...more >>

Hi Is it possible and to use the MeasureString method without the PaintEventArgs object Thank you, Samuel ...more >>

Hi there, i have a string thatt i draw in the visible surface of a control with a specific font.Later i want to obtain the rectangle that wraps that string to put a background color to the string. I have tried to do it with measure string method but that method doesn´t give me the exact rect...more >>

Given a Bitmap object, I need to test if it is using alpha transparency. Any idea on how to quickly detect that (possibly something smarter than testing the pixels one by one) ? -tom ...more >>

Hi There, Is there a way to list/enumerate all GDI+ Brushes? Thanks ...more >>