magickimage.net (C#) image saturation when converting format? - c#

I tried to use magickimage.net (C#) to convert HEIC image files (from iPhone 7) to JPG format.
Using all the default values (see below), though it converts successfully -- however, when comparing the converted image, vs, if I copy the files from iPhone directly to my computer as JPG, I noticed the images converted from magickimage look more "pale", lacking vivid color (saturation, I would say).
Just wondering if anyone happens to know the right settings to improve that?
using (MagickImage image = new MagickImage(files[i]))
{
image.Format = MagickFormat.Jpeg;
image.Write(MyFile.ReplaceFileExtension(files[i], "jpg"));
}

Just a guess, most likely not apply the correct color profile.
Check the image if it has Color properties ie. Table VII. Image Properties and Figure 1 in the Technical spec for HEIF is at:
https://nokiatech.github.io/heif/technical.html
Also I would check if the following display the image correctly.
https://github.com/liuziangexit/HEIF-Utility/tree/master/HEIF%20Utility%20English

Related

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More than that, the code you mention belongs to iText 5, which is end of life and no longer maintained (with an exception of considerable security fixes), so it's recommended to update to iText 7.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

How to remove metadata from jpg and png images

This should be a pretty trivial programming task in C#, however after I have searched a while I simply cannot find anything relevant on how to remove metadata.
I want to remove jpg and png image metadata such as: folder path, shared with, owner and computer.
My application is an MVC 4 application. In my website users can upload an image I get this image at this ActionResult method
if (image != null)
{
photo.ImageFileName = image.FileName;
photo.ImageMimeType = image.ContentType;
photo.PhotoFile = new byte[image.ContentLength];
image.InputStream.Read(photo.PhotoFile, 0, image.ContentLength);
}
Photo is a property in the model, goes like this.
public byte[] PhotoFile { get; set; }
I imagine the way to remove above mentioned metadata or just all metadata, would be to use some coding like this
if (image != null)
{
image = image.RemoveAllMetaData; !!!
I dont mind using some 3rd party dll as long as it is compatible with NET 4.
Thanks.
'Metadata' here is a bit ambiguous--Do you mean the data which is required for a viewer to properly determine the image format so it can be displayed, saving only the raw image data? Or, more likely, do you mean the extra information, such as author, camera type, GPS location, etc, that is often added via the EXIF tags?
If you mean something like the EXIF data, there's a lot of programming material already on the web about how to add/modify/remove EXIF tags, and even some apps which already strips such tags: http://www.steelbytes.com/?mid=30 for example.
If you mean you just want the raw image data, you'll probably have to read and process the image first, since both JPEG and PNG do not contain simply the raw image data; It's encoded with various methods--which is why they contain metadata to tell you how to decode it in the first place. You'll have to learn/explore the JPEG and PNG data formats to extract the original raw image data (or a reasonable facsimile in the case of a "lossy" encoding).
All the above is well-documented on various websites which can be found on Google, and many include image manipulation libraries which can handle these chores for you. I suspect you just didn't know to search for something like "JPEG PNG EXIF METADATA".
BTW, EXIF applies to JPEG's, where EXIF is, loosely (and not fully technically correct) an addition of data (extension) to the end of the JPEG file, which can usually simply be truncated to remove. A quick Google search for me turned up something like libexif.sourceforge.net and other similar results.
I'm not entirely certain about the PNG format, but I believe the PNG format (which does call such items "metadata" as well) was written to include such data as part of the file format rather than an "extension" tagged on after the fact like EXIF is. PNG, however, is open source, and you can obtain libraries and code for manipulating them from the PNG website (www.libpng.org).
There's an app for that but it's written in Perl. It doesn't recompress the image and it's here http://www.sno.phy.queensu.ca/~phil/exiftool
Found it in this thread
How to remove EXIF data without recompressing the JPEG?
Do what all the social media websites do. Create a new image file, stream in the image byte data and use the file you created than the original one that was uploaded. Of course, now you will need to find out the original image's color depth and so on so that the image you create is not of a lower quality -- unless you need to do a disk or image resize as well.

Reading raw image files in c#

How do i decode/open raw image files like .CR2 or .NEF and .ARW without having the codec installed, something like lightroom open raw files ? My code look like this:
if (fe == "CR2" | fe == "NEF" | fe == "ARW" )
{
BitmapDecoder bmpDec = BitmapDecoder.Create(new Uri(op.FileName), BitmapCreateOptions.DelayCreation, BitmapCacheOption.None);
BitmapSource bsource = bmpDec.Frames[0];
info_box.Content = fe;
imgControl.Source = bsource;
}
This work only with the raw codecs installed and dont work with ARW format.
If you don't have a codec installed, then you'll have to read the raw image data and convert it to a bitmap or other format that you can read. In order to do that, you need a copy of the format specification so that you can write code that reads the binary data.
I strongly recommend getting a codec, or finding code that somebody has written that already handles the conversion. But if you really want to try your hand at writing image format conversion code, your first order of business is to get the format specification.
A quick Google search on [CR2 image format] reveals this Canon CR2 Specification. Truthfully, I don't know how accurate that is, but it looks reasonable. A little time with a search engine will probably reveal similar documents for the other formats.
Be forewarned: writing these conversions can be a very difficult task. Again, I recommend that you find some existing code that you can leverage.
If you insist on not installing a codec, then your best bet might be these:
http://www.cybercom.net/~dcoffin/dcraw/
- written in C, supports most cameras
http://sourceforge.net/projects/dcrawnet/
- apparently a (partial?) port of DCRAW to C#, but project does not seem to be active

RawData is equal null for jpg images

I want to add image to pdf file. I'm using iTextSharp for this.
I have the following code:
var imageBanner = iTextSharp.text.Image.GetInstance(bannerImagePath);
The problem in that the RawData property is equal NULL for jpg images, but for png is all ok.
Please read chapter 10 of the book "iText in Action". The Image class is abstract. It has different implementations for different image types. Some image types exist in PDF. For instance: a JPG (DCTDecode) can be copied literally into a PDF. File types such as PNG and GIF don't exist in PDF, so they need to be converted to raw data first; they are compressed (FlateDecode) later on in the process.
As there's absolutely no need for any 'processing' when dealing with JPGs, no memory is wasted on creating a raw image. It would be bad if RawData weren't null, hence my question: why is it a problem for you? you should be happy that RawData is null!

Convert SVG-stream to png or jpg

I would like to use iText to add images to some PDF-documents using C#.
My problem is, that the images are saved as a stream (fx. M47,33 L47,34 L47,37 L47,40 L47 etc.) in the database.
I can't figure out, how to convert this to PNG or JPEG so I can add them to the PDF-documents.
Can anyone tell me how to make this convertion, or if it can be done directly in iText?
Converting SVG images to png in c#
You could use http://librsvg.sourceforge.net/
It does not have a C# binding as far as I can see, but it should be possible to use it via P/Invoke.
EDIT: iText seems to have some conversion, too: http://itextpdf.com/examples/iia.php?id=263

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