Loading font-family from disk to PrivateFontCollection - c#

I'm using the following code to load a font into memory for generating an image with GDI+:
var fontCollection = new PrivateFontCollection();
fontCollection.AddFontFile(Server.MapPath("~/fonts/abraham-webfont.ttf"));
fontCollection.Families.Count(); // => This line tells me, that the collection has 0 items.
There are no exceptions, but the fontCollection Families property is empty after the AddFontFile method has run without any exceptions.
I've verified that the path is valid (File.Exists returns true):
Response.Write(System.IO.File.Exists(Server.MapPath("~/fonts/abraham-webfont.ttf"))); // # => Renders "True"
The TTF-file seems to work fine, when I open the file, so it's not an invalid TTF-file:
Any suggestions?

Answer from Hans Passant solved the problem:
PrivateFontCollection is notoriously flakey. One failure mode that's pretty common today is that the font is actually an OpenType font with TrueType outlines. GDI+ only supports "pure" ones. The shoe fits, the web says that Abraham is an OpenType font. Works in WPF, not in Winforms.

Related

Check a Font for a 32bit Unicode Glyph [duplicate]

How can I determine from the .NET runtime if, for a given font, if it has the glyph for a character? I want to switch the font to Arial Unicode MS if I have text that the specified font does not have a glyph for (very common for CJK).
Update: I'm looking for a C# (ie all managed code) solution. I think GlyphTypeface may be what I need but I can't see a way in it to ask if a given character has a glyph. You can get the entire map back, but I assume that would be an expensive call.
I've done some unicode tools and the technique I use is getting the map and chache it
for each font used.
IDictionary<int, ushort> characterMap = GlyphTypeface.CharacterToGlyphMap
will give you the defined glyph index per codepoint.
msdn ref
if (characterMap.ContainsKey(CodePoint))
glyphExists = true;
else
glyphExists = false;

Convert iTextSharp.text.pdf.BarcodeQRCode to System.Drawing.Image

Looking for a way to convert iTextSharp.text.pdf.BarcodeQRCode to System.Drawing.Image
This is what I have so far...
public System.Drawing.Image GetQRCode(string content)
{
iTextSharp.text.pdf.BarcodeQRCode qrcode = new iTextSharp.text.pdf.BarcodeQRCode(content, 115, 115, null);
iTextSharp.text.Image img = qrcode.GetImage();
MemoryStream ms = new MemoryStream(img.OriginalData);
return System.Drawing.Image.FromStream(ms);
}
In line 3 above using img.OriginalData returns null
Using img.RawData on line 3 instead thows invalid parameter error on line 4.
I've googled some of the code samples on how to perform the thing you want and your code (the "OriginalData" approach) is basicaly the same: https://csharp.hotexamples.com/examples/iTextSharp.text.pdf/BarcodeQRCode/-/php-barcodeqrcode-class-examples.html .
However, I don't see how it could work. From my investigations of BarcodeQRCode#getImage it seems that OriginalData is not set while processing such a barcode, so it will always be null.
More than that, the code you mention belongs to iText 5, which is end of life and no longer maintained (with an exception of considerable security fixes), so it's recommended to update to iText 7.
As for iText 7, I do see how to achieve the same in Java, since barcode classes do have a createAwtImage method there. .NET, on the other hand, lacks such a functionality, so I'd day that one unfortunately couldn't do it in .NET.
There are some good reasons for that. iText's Images (and a barcode could be easily converted to an iText's Image object as shown here: https://kb.itextpdf.com/home/it7kb/faq/how-to-generate-2d-barcode-as-vector-image) represent a PDF's XObject. In PDF syntax, an image file (jpg, png, etc.) is an XObject with the raw image data stored inside. However, an XObject can also contain PDF syntaxt content (it is not just used for image files). So to render such a content one needs to process the data from PDF syntax to image syntax, which is not that easy. There are some means in Java's awt to do so, that's why it's implemented in Java. As for .NET, since there is no out-of-the-box means to convert PDF images to System.Drawing.Image, it was decided not to implement it.
To conclude, there is another iText product, pdfRender, which allows one to convert PDF files (and you could create a page just for a barcode) to images. Perhaps you might want to play with it: https://itextpdf.com/en/products/itext-7/convert-pdf-to-image-pdfrender

While extracting text from PDF file using iTextSharp, I am getting this error: “Could not find image data or EI”

While extracting text from PDF file using iTextSharp using the below piece of code, I am getting this error: “Could not find image data or EI” while debugging the code found that this error is coming in certain pages but not all pages, then further investigated and also found that generally there are two types image in pdf xObject image and Inline Image and using the below piece of code Inline Image ca not be handled. There are few few comments in this issue in other similar post that suggested to use latest version(5.5.0) itextsharp, that also i did but no luck. My basic purpose is to extract the text in the page not image. How can I handle the Inline image or how can I extract only the text regardless what type of image the page having.
for (int page = 1; page <= pdfReader.NumberOfPages; page++)
{
PdfContentByte pdfData = pdfStamper.GetUnderContent(page);
LocTextExtractionStrategy its = new LocTextExtractionStrategy();
pdfData = pdfStamper.GetUnderContent(page);
string extractedTextInCurrentPage=PdfTextExtractor.GetTextFromPage(pdfReader, page, its);//In this line exception is throwing
}
Please share your PDF.
This is why:
Your PDF contains an inline image. Inline images are problematic in ISO-32000-1, but I personally saw to it that the problem will be solved in ISO-32000-2 (for PDF 2.0, to be expected in 2017).
In ISO-32000-1, an inline images starts with the BI operator, followed by some parameters. The length of the image bytes isn't one of those parameters. The actual image bytes are enclosed by an ID and an EI operator.
Software parsing PDF syntax needs to search for these operators and usually does a good job at it: find BI, then take the bytes between ID and EI. However: what to do when you encounter an image of which EI is part of the image bytes?
This hardly ever happens, but it was reported to us as a problem and we solved this in recent iText versions by converting the bytes between ID and EI to an image. If that fails, iText continues searching for the next EI. If iText doesn't find that EI parameter, you get the exception you mention.
This is a cumbersome process and, being a member of the ISO committee that writes the PDF standards, I introduced a new inline image parameter into the spec: the parameter /L will informs parsers exactly how many bytes are to be expected between the ID and EI operators. At the same time, I saw to it that the recommendation of keeping inline images smaller than 4 KB became normative: in PDF 2.0, it will be illegal to have inline images with more than 4096 bytes. Of course: this doesn't help you. PDF 2.0 doesn't exist yet. My work in the ISO committee only helps to solve the problem on the long term.
On the short term, we've written a work-around that solves the problem for the PDFs that were reported to us, but apparently, you've found a PDF that escapes the workaround. If you want us to solve the problem, you'll have to share the PDF.

System.Drawing.FontFamily->IsStyleAvailable always returns true

Im using a PrivateFontCollection to load a font via the AddMemoryFont. I retrieve the FontFamily, and then I query it using IsStyleAvailable to determine what the font supports as styles. However, with myriad fonts every single call to IsStyleAvailable returns true.
PrivateFontCollection pfc = new PrivateFontCollection();
var fontBuffer = Marshal.AllocCoTaskMem(dta.Length);
Marshal.Copy(dta, 0, fontBuffer, dta.Length);
pfc.AddMemoryFont(fontBuffer, dta.Length);
System.Drawing.FontFamily fam = pfc.Families[0];
if (fam.IsStyleAvailable(d.FontStyle.Bold)) //do something
Does anyone know how to get the actual style information from the FontFamily? If you look at the C:\Windows\Fonts folder you can see the supported styles. For example: Agency FB supports Bold; Regular, but when I query it in this fashion I get styles for Underline, Strikeout, and Italic, as well as Bold and Regular.
Is there a better way to go about this?
The font engine in Windows knows how to synthesize a style from the unstyled base font. It isn't particularly difficult to do on paper, just makes the stems fatter to get bold, tilt them to get italic, draw a line to get underline or strike-out. It isn't exactly as pretty as the dedicated outlines that a good designer will create but it certainly gets the job done. So when you ask "can you do that?" then you'll get a resounding "sure thing!"
Since you explicitly added the TTF files, you already know what styles are directly supported without synthesis and should not need to ask. Finding out anyway is perhaps possible with pinvoke and/or digging through the TTF tables but it is going to be ugly and certainly not directly supported by .NET. There's no winapi function I know of that tells you directly.

Using Imageresizer Watermark plugin to write text: Centered, width and line feeds

I'm trying to use the watermark plugin to write text on images for my project. Right now I'm trying to find out how to set a "width" for a writing box so I can get automatic line returns. Is there a way to do this with the watermark plugin?
Also I'm trying to see if I can get a "text-align: center" effect when I'm writing my text (possibliy in relation to that set width), how could I get that setup?
I'm thinking that the alternative to this would be to have code driven line returns and centering, but this would mean that I would have to count the width of my characters and this seems like a world of pain hehe
Here is a code sample that shows what I'm doing (this currently works):
var c = Config.Current;
var wp = c.Plugins.Get<WatermarkPlugin>();
var t = new TextLayer();
t.Text = panty.Message;
t.TextColor = (System.Drawing.Color) color;
t.Font = fonts[myFunObject.Font];
t.FontSize = fontSize[myFunObject.LogoPosition];
t.Left = new DistanceUnit(5, DistanceUnit.Units.Pixels);
t.Top = new DistanceUnit(5, DistanceUnit.Units.Pixels);
wp.NamedWatermarks["myFunObjectMessage"] = new Layer[] { t };
EDIT: I also have to mention that the text I'm writing is user submitted so it's different everytime. If you want a similar case, think about thos funny cat images with funny text captions on them. This project is quite similar to that. (Minus the cats)
Thanks for the help!
Basically, System.Drawing (and therefore the current version of Watermark) are very primitive about line wrapping.
As you mentioned, you can do hacky stuff with character counting and separate MeasureString calls with loops, but the results are only barely acceptable.
You may try to fork the Watermark source code and hack support for your use case. I don't see a way to improve Watermark in a generic way without replacing the underlying graphics engine first (which may happen anyway).
System.Drawing has unsurpassed image resampling quality. Text wrapping, though, it kind of stinks at.

Categories