Is there a way to draw an emf metafile (exported form a drawing tool) with antialiasing enabled? The tools I tried are not capable of exporting emf files antaliased so I wondered if I can turn it back on manually when drawing the emf in the OnPaint override of my Controls.
If anyone can confirm that is technically possible to generate antialiased emf files, another solution would be to use a drawing tool that can export to antialiased emf or have a 3rd party converter do this later. If anyone knowns such a tool, please let me know.
EDIT: When looking at the emf instructions it doesn't seem that emf itself can actually store the information whether it is to be rendered antialiased or not. At least I couldn't find anything. It is more likely that the antialiasing is done by the playback engine. For example when I open an emf in Word 2007 it is rendered antialiased. But not when I draw it with GDI+ "playback engine" (Graphics.DrawImage(...)). or when I view it the standard windows image viewer.
This makes me believe that some tools actually have their own emf playback engine. So maybe there is free .NET library (preferably with source code) that give me an object model of the emf instructions stored in the parsed emf file so I can play it back myself instead of using Graphics.DrawImage(...)?
We had a similar issue in a DirectX project. Upscaling and downscaling works to a certain degree, but it's faking it. If it's something you need to do over and over, you could perhaps parse the records of the WMF and draw them with GDI+ antialiased.
The following threads back this up (but they're from 2005 so things might have changed):
http://www.dotnet247.com/247reference/msgs/28/144605.aspx
http://www.dotnetmonster.com/Uwe/Forum.aspx/dotnet-sdk/1127/Graphics-DrawImage-metafile-no-antialiasing
[Edit:]
These three programs might do the job for you: I'm assuming you're ok with doing it by hand:
http://emf-to-vector-converter-command-line-ser.smartcode.com/info.html
http://www.verypdf.com/pdf-editor/index.html
http://www.ivanview.com/converter/emf-batch-converter.html
[Edit II:]
Well, here's a program that will let you inspect an EMF in various ways:
http://download.cnet.com/windows/3055-2383_4-10558240.html?tag=pdl-redir
...and here's a freeware library that will let you parse 122 of the EMF commands and output them in GDI+. That should probably do the trick:
http://www.codeproject.com/KB/GDI-plus/emfexplorer.aspx?msg=2359423
...oh, and notice also comment #3 on the codeproject page. Looks like someone have banged their heads against the wall before. Hope this solves your problem.
EMF is using GDI commands, not GDI+, so it has no notion of antialiasing. I suspect that when you ask GDI+ to render the file, it sends it to GDI and just copies the resulting bitmap.
Duplicating this in code would be the same as reimplementing GDI, so it's not terribly feasible. Not impossible, just a larger job than the benefit would justify. If there is an open source utility that can open EMF files outside of Windows, you might look into the source code.
My guess is that Word is using the downsampling trick.
EMF file is a list of GDI commands. So it won't be anti-aliaised, even if under GDI+, you put a SmoothingMode() call before the drawing. You'll have to enumerate the GDI commands, then translate it into GDI+ commands.
Under Vista/Seven, you can use GDI+ 1.1 function named GdipConvertToEmfPlus/ConvertToEmfPlus. If you want your program to work with XP, you should write your own enumeration, then conversion to GDI+ commands.
The GDI enumeration then conversion to GDI+ is possible has been done by emfexplorer, but I've written some code perhaps more easy to follow, even if it's written in Delphi.
I'm putting this answer just now (I'm late), because I spent a lot of time finding out a solution using ConvertToEmfPlus, and writing some tuned open source code in case this method is not available.
Related
I'm writing a service for a project that's going to handle our image processing. One such process is supposed to strip all metadata from the byte[] provided and return the same image as a byte[].
The method I'm currently working on involves always converting the image to a Bitmap, then converting it back to the original format and returning the data from a MemoryStream.
I haven't been able to test it yet but something tells me I'm going to experience some quality loss.
How can I remove all metadata from any image with a common format?
(bmp, gif, png, jpg, icon, tiff)
Not sure how I can narrow that down any further. Would be nice if I got some feedback regarding the downvotes.
For the lossless formats (except JPEG), your idea of loading it as a bitmap and re-saving is fine. Not sure if .NET natively supports TIFFs (I doubt it does).
For JPEGs, as you suggested there may be quality loss if you're re-compressing the file after decompressing it. For that, you might try the ExifLibrary and see if that has anything. If not, there are command line tools (like ImageMagick) that can strip metadata. (If you use ImageMagick, you're all set, since it supports all of your required formats. The command you want is convert -strip.)
For TIFFs, .NET has built-in TiffBitmapDecoder and ...Encoder classes you might be able to use; see here.
In short, using an external tool like ImageMagick is definitely the easiest solution. If you can't use an external tool, you're almost certainly going to need to special-case the formats that .NET doesn't support natively (and the lossy JPEG).
EDIT: I just read that ImageMagick doesn't do lossless stripping with JPEGs, sorry. I guess using the library I linked above, or some other JPEG library, is the best I can think of.
For some reasons, I need to write few image processing functions without using GDI+. I need to be able to do the following operations on images.
Draw some shapes on existing images (mostly rectangle with a plain background color). Regularly i do this using Graphics.DrawImage() function in GDI+.
Draw texts on existing image. Regularly I do this using Graphics.DrawString() function in GDI+
Save image to MemoryStream. Regularly I do this by Image.Save(stream, imgformat) function in GDI+
Get image bytes. Regularly I do this by MemoryStream.ToArray() function. I need bytes because I need to be able to send image to HttpContext() using the context.Response.BinaryWrite(imageBytes) method.
I've already looked at AForge.net, but it is missing Image.Save() method. It uses native Bitmap.Save() method of GDI+. So I seem to have no way of surviving GDI+ with AForge.
I've also looked at OpenCV and its .NET wrapper Emgu, but after 2 days of hard try, I was not able to successfully integrate the project into my own project (I know this sound silly, but that is truth. Following all the tutorials, probably 20+ SO posts on this did not help, because my solution structure is a little bit more than (more complex) a regular solutions).
How can I achieve this? Show me some way please. Have you even found yourself in such a situation (situation where you need to process images, but no GDI+)? What are the other libraries that could help me?
There's a recent project that's gathering momentum called, appropriately, "ImageProcessor": https://github.com/JimBobSquarePants/ImageProcessor - NuGet reports over 344,000 downloads as of June 2016.
Scott Hanselmann did a feature on it about 8 months ago, explaining the motivation given that .NET Core does not have System.Drawing (and I note that Windows Azure does not officially support GDI in Website Roles): http://www.hanselman.com/blog/RFCServersideImageAndGraphicsProcessingWithNETCoreAndASPNET5.aspx
I just attempted to answer a similar question here:
server-side graphics generation in .net/c#
Adding any other vector graphics (and layout) would be quite simple as well. Let me know if you would like a sample project or code.
i'm using c# tessnet2 wrapper for Tesseract OCR engine to capture chracters of image files. i been searching everywhere if tessnet2 has any build in functions to overwrite certain characters and saved them into the same image file it's reading but have not found anything in regards to that. so what i'm thinking of doing is creating a new imagine file base on what i'm receiving from tessnet2 but i need to create the new image the same exact way but change just few things in the new created image. i'm not sure if i'm using the correct methology or if there is other c# assemblies out there that allow you to read characters from image file and at the same time allow you to manipulate as you need them.
Good luck--but tess has no way of replacing in the proper font. Raster graphics don't generally store glyph information. Even if it did, you would potentially be in violation of licenses and/or copyrights surrounding the fonts you'd be writing in. I'm not an expert in OCR, but I will confidently say that this is something not readily available out there in the wild.
To expand on Brian's answer:
You will need to do this yourself. I have not worked with Tesseract, but I have used the Nuance OCR engine. It will return you font information as well as coordinates for the character it has recognized (note that you will most likely have to compute the actual image coordinate as the OCR engine will have deskewed the image before performing the recognition). Once you get the coordinates and the deskew so that you can compute the actual coordinate, you can then use any image manipulation library (Leadtools, Accusoft, etc) or just straight GDI+ functions to clear the character, then using the font info and size info create a new character and merge it into the image. This is not trivial but certainly doable.
Edit:
It was late when I wrote the initial answer, wanted to clarify what is meant by font information. The OCR engine will give you information regarding the point size, whether its bold/italicized and the font family (Seriph, etc). I do not know of one that will tell you the exact font that the document is in. If you have a sample of the documents that you will process, then you can make a good guess based on the info the OCR engine gives you.
I searched on how to check if a TIFF file is corrupt or not. Most suggests wrapping the Image.FromFile function in a try block. If it throws an OutOfMemoryException, its corrupt. Has anyone used this? Is it effective? Any alternatives?
Please check out the freeware called LibTiff .NET. It has the function to check if every page in a TIF file is corrupted or not. Even partially corrupt also no problem
http://bitmiracle.com/libtiff/
Thanks
Many tiff files won't open in the standard GDI+ .NET. That is, if you're running on Windows XP. Window 7 is much better. So any file which is not supported by GDI+ (i.e. fax, 16 bit gray scale, 48bpp RGB, tiled tiff, piramidical tiled tiff etc.) are then seen as 'corrupt'. And not just that, anything resulting in a bitmap over a few 100 MByte on a 32-bit system will also cause an out-of-memory exception.
If your goal is to support as much as possible of the TIFF standard, please start from LibTiff (derivates). I've used LibTiff.NET from BitMiracle (LGPL), which worked well for me. Please see my other posts
Many of the TIFF utilities are also based on LibTIFF, some of them are ported to C#.NET. This would be my suggestion if you want to validate the TIFF.
As for the TIFF specification suggested in other replies: of course this gives you bit-level control. But to my experience you won't need to go that low to have good TIFF support. The format is so versatile that it will cost you an enormous amount of time to start support from scratch.
It will only be corrupt in the sense that the frameworks methods cant open it.
There are some TIFF types that the framework cannot open -( In my case I cant remember the exact one, think it was one of the FAX type ones...)
That may be enough for you, if you are just looking a using the framework to manipulate images. After all I you cant open it, you cant use it...
ImageMagic - may give you more scope here
Without looking at the tiff, it may be difficult to see if its corrupt from a visual perspective, but if you have issues with processing an image, just create a function that does a basic test for this type of processing and handle the error?
This is in regards to Adobe's Image Resource Blocks(IRB), that they store in TIFF, PSD, JPEG Formats. It's also called "8BIM", This standard was released with Adobe's Photoshop 3 (November 1994).
IRB contains information on color profiles and clipping paths(what i am interested in).
The only piece of documentation i can find on the internet is this 4 page document provided by Adobe in 1990.
I have been searching imagemagick source code to find that the IRB ID's for clipping paths are from 2000 to 2998, to thats a usable 998 clipping paths.
So I managed to get a IRB Byte Array of each resource block from JPEG and a TIFF file, specified in the four page document. I rolled my own and tested out Graphics Mill to see if managed to get the same information.
I am not sure how to convert the clipping path byte array into anything usable since I don't even know the format that adobe photoshop uses. The idea was to map the clipping path to a c# GDI+ Graphics Path.
I think that it's kind of pathetic that adobe has been around for so many years being the industry leader in graphic design, but yet they can't even provide necessary documentation.
Can anybody suggest any documentation that i could use?
Barely it's still actual for you, but some info can be found here
http://www.adobe.com/devnet-apps/photoshop/fileformatashtml/PhotoshopFileFormats.htm
+1 to mistika
Adobe specification contains description of PSD clipping path. The last revision is dated by Oct 2013 and looks like Adobe is currently working on it. At least I have feeling that new stuff was added.
If you are looking for a code using PSD format, take a look into libpsd. That’s a nice open source, pretty easy to read. Sometimes more informative that spec.
As for GraphicsMill, since 6x version it can transform Adobe Clipping Path to GdiPlus GraphicsPath.