I'm using EmguCV (It is .Net wrapper to the OpenCV image processing library).
I need to compare two images and check if this is the same person in both images.
Yes. But not directly in emgu, unless you want to make a lot of code.
Have a look at this page https://azure.microsoft.com/en-us/services/cognitive-services/face/
Here you supply two images and get score back.
It should be easy implementing the API
Related
Without using System.Drawing?
I have a C# application that receives a list of filepaths pointing to a number of .PNG files. I would like to extract an array of pixel (color) data from the image, but I am having trouble determining the best way to extract that.
I had originally hoped to be able to use System.Drawing, as outlined in this answer, but I am unable to access System.Drawing, since my application (Unity3d) uses OpenGL (and therefore, is incompatible with System.Drawing)
The PngBitmapDecoder is likewise out of reach of the application. Is there any other way I can extract the data I'm interested in, short of writing my own PNG Decoder?
If you are using Unity, then you have access to their API which does exactly what you need.
http://docs.unity3d.com/Documentation/ScriptReference/Texture2D.LoadImage.html
http://docs.unity3d.com/Documentation/ScriptReference/Texture2D.GetPixels.html
http://docs.unity3d.com/Documentation/ScriptReference/Texture2D.GetPixels32.html
Hi and thanks for looking!
Update
For the sake of clarity, a third-party .NET library is just fine. Preferably an open-source or free one. The solution need not be native .NET.
Background
I am working on an enterprise web application for which the client has given us thousands of pages of content in MS Word documents that we have to parse, extract data, and send to the content database.
Within these docs are various embedded images representing a larger original image in a separate folder.
The client did not provide any paths to the original source image, so when we see content with an embedded image in the MS Word doc, we have to go through several "assets" folders and look for the corresponding image which is extraordinarily time consuming.
We are already using DocX to parse the documents, so you can assume that we have a list of bitmap images to loop through that we have pulled from the document.
Question
Given a list of bitmaps that we just extracted from the document, how do we search a different folder containing hundreds of images, for the matching image, and then return the file path to it?
TinEye.com does this over the web. I am wondering if, using System.Drawing or something, we can do it on a PC with C#.
Thanks!
Matt
Hate to propose an answer to my own question, but I think I might be on to something here. Here is heuristic/pseudo code for a C# forms app--your thoughts are appreciated:
Part 1
Using System.IO, traverse the "assets" folders and get all images.
For each image, Base64 encode it.
Take the resulting string and place in an XML file:
<Image>
<Path>C:\SomePath</Path>
<EncodedString>[Some Base64 String]<Encoded String>
</Image>
Now we have an XML file containing all original images, in Base64 form, along with their file path.
Part 2
Using DocX, extract all images from MS Word Doc.
For each image, use Linq-to-Xml to search for an exact match in the XML file from Part 1.
If there are no exact matches, start iterating the XML file and computing the Levenshtein distance.
While in the foreach store the XML node Id (or file path) and Levenshtein Distance as a key value pair in an object.
Take the k/v pair with the lowest LD score and return the file path.
For performance, set tolerance so that the foreach stops if a certain original image has an acceptably low LD score when compared to the image extracted from the document.
Since this is a one-off task, I don't need instant performance. So, I could run this tonight before leaving the office and, hopefully, come back tomorrow to a list of paths connecting the original images to the ones embedded in the docs.
UPDATE
The heuristic above worked beautifully! I ended up using the Sift library to efficiently calculate distances between Base64 strings. Specifically, I used their FastDistance() method. Having 100% accuracy on finding the images I need, even if the angle from which the photo was taken is slightly different.
There is no built-in algorithm in the .NET framework for generating image similarity. You'd need to use a third-party library or do it yourself. Lots of image similarity algo questions on SO:
Algorithm for finding similar images
How can I measure the similarity between two images?
comparing images programmatically - lib or class
One more, for .NET: Are there any OK image recognition libraries for .NET?. This one refers you to AForge, which seems to have the algorithm that you are after.
According to this SO answer to a similar question, you should look at OpenCV and VLFeat. The former has a C++ API and the latter a C API, so you would need to write your own P/Invoke wrapper or perhaps wrap them in a C++/CLI facade, which you could call from C#.
suppose I have two images one contains circle and other contains square,I just want to give input as this images. program should recognize which one is circle and which one is square. how i can implement this using c# language?
There are a few image recognition libraries out there. Try aforge: http://code.google.com/p/aforge/. Another one is EmguCV for .Net.
using Emgu.CV:
exactly what you want:
http://www.emgu.com/wiki/index.php/Shape_(Triangle,_Rectangle,_Circle,_Line)_Detection_in_CSharp
hi
I am developing a video capture application using C#.net. i captured
video through webcam and saved it as a JPEG images then i want to make a
wmv file with those images. how can i do that what are the basic steps needed for that can any body help
I am working on this myself. I have found two ways that may be possible - both require the purchase of an outside library.
The first one looks to be the easiest but costs the most, although it will allow you to use it for free you will just have to deal with a pop up telling you to purchase the library: http://bytescout.com/products/developer/imagetovideosdk/imagetovideosdk_convert_jpg_to_video.html
The other involves using Microsoft Encoder 4. I am still working on this one. You can get the free version here: http://www.microsoft.com/download/en/details.aspx?id=18974
C# doesn't natively support much in the way of sound or video so outside reference assemblies seem to be a necessity.
Right now that is the best help I can offer until I figure it out.
Can I compare 2 images and show the difference using C#?
How?
Sure you can. One (slow) way to do so would be to create a new empty image and then use GetPixel and SetPixel to construct the difference image.
Could be useful perform an image substraction (maybe better in GrayScale mode) as shown here:
How to subtract one bitmap from another in C#/.NET?
There is technology called SIFT( Scale Invariant Feature Transform ).This algorithm generates a feature file from an image in which it has salient points of that Image. This file is called SIFT feature.
You have to generate the SIFT feature file for the images that you want to compare. Then this technology has a matching function which you can use to compare the feature files. This function returns a number. the higher the number the more similar the images. in this way you find the most similar images from within a set.