i'm a newbie in computer vision.
i using emguCV v3.2 for my application and tesseract version 3.0
my application is detect number of electric meter..
i used file data language for tesseract download here:
https://github.com/tesseract-ocr/tessdata/blob/master/eng.traineddata
after preprocess image then i have image below. but tesseract detect to: 033478
i can not understand why tesseract detect not correct number 6 to number 8??
number
Maybe the image isn't optimized try to do some preprocessing optimization.
Here is a tutorial that walks you through the preprocessing tuto, for me the ghost script was sufficient
Related
I am working on an app that requires the use of a camera to scan in text. Basically without getting too detailed, I need to point the camera at something (for my purposes here I will say a license plate) and i need to point the camera at the plate, and have it somehow save the digits into a string within the app. i guess its similar to Word Lens or red laser where it doesnt actually take a picture, it just scans the view and returns information. i have not been able to find much about this so any help on how to write this kind of code would be greatly appreciated!!
This is not barcode scanning. This is called OCR (optical character recognition), and there are some free and opensource libraries available that do this.
For example, Tesseract is a complete OCR engine written in C++ (it has a C++ interface, so it can be easily used from within an iOS app).
The other solution is gocr, the GNU Optical Character Recognizer. This is supposed to be a standalone program (a command line tool), but I've had success extracting its essential parts into a library (and I used it in an iOS project of mine as well).
OpenCV is a complete computer vision library. You can implement OCR using it - just google for the adequate documentation and tutorials.
I am working on developing an iOS video app that needs to do stuff like apply filters, adjust brightness/contrast/saturation add overlays etc. As I am new to image processing I am not able to judge which resources (i.e. APIs, open source libraries) I can use. So any guidance from those who have experience in this field will be of great help.
Here is a great tutorial about GPU-accelerated video processing on Mac and iOS:
http://www.sunsetlakesoftware.com/2010/10/22/gpu-accelerated-video-processing-mac-and-ios
Use OpenCV.
1. Get OpenCV
Check out OpenCV homepage to download OpenCV source.
2. Check out this SOF for more details on OpenCV on iOS
iPhone and OpenCV
3. Get and read some good books on OpenCV
The best book on OpenCV is "Learning OpenCV" written by Gary Bradsky, main founder of OpenCV.
Second one is "OpenCV cookbook".
These books contains lots of examples on OpenCV along with description
4. Check out OpenCV documentation.
OpenCV documentation contains details of complete functions. It also includes a lot of tutorials, which are really good for all.
5. Also try running OpenCV samples. It contains a lot of good programs
All the best.
I have used the library for reading barcode from image. But can't find any source or help for reading numbers from image.
I just need to take photo with camera and then process image whether any numbers exist and read out the numbers.
Is there any way to get the number written on image?
that's OCR type of problem. you might want to take a look at: Is there any good OCR API for iPhone and/or Android phones? or iPhone: Regarding OCR technology?
The Google Docs API has some OCR support. You may want to take a look at this and see if you can implement it: http://googlesystem.blogspot.com/2009/09/google-docs-ocr.html I don't remember if Apple will allow you to use any external libraries though.
Is there any library alternative to OpenCV which detects smile.
I dont want to use OpenCV as it sometimes fails to detect faces due to background.
Any one knw other library ? other than OpenCV ?
I would recommend having a look at The Machine Perception Toolbox (MPT Library).
I had a chance to play with it a bit at an Openframeworks OpenCV workshop at Goldsmiths and there is a c++ smile detection sample available.
I imagine you can try the MPT Library for iPhone with openframeworks or simply link to the library from an iphone project.
sometimes fails to detect faces due to
background.
An ideal lighting setup will guarantee better results, but given that you want to use this on a mobile device, you must inform your users that smile detection might fail under extreme conditions (bad lighting)
HTH
How are you doing smile detection? I can't see a smile-specific Haar dataset in the default OpenCV face detection cascades. I suspect your problem is training data rather than OpenCV itself.
Egawer is a good starting point if you need a working app to begin with.
https://github.com/Atrac613/egawer-iOS
I checked the training images of smileD_haarcascade_v0.05, an found that they include the full face. So, it seems to be a "smiling face" detector rather than a smile detector alone. While this seems easier, it can also be less accurate.
The best is to create your own Haar Cascade XML file, but admittedly most of us developers don't have time for that. You can improve the results considerably by equalizing the brightness of the image.
iOS 7 now has native support of simile detection in CoreImage. Here is the API diff:
For iOS 7, Yes, now you can do it with CoreImage.
Here is the API diff in iOS 7 Beta 2:
CoreImage
CIDetector.h
Added CIDetectorEyeBlink
Added CIDetectorSmile
I want to develop an iPhone application that is going to convert some sort of images to text formats. I want to know that is there any built-in library for achieving this purpose?
I suppose you are asking about recognizing text from images (OCR) and not about something like encoding image file into base64
There's no build-in OCR libraries in iPhone.
Depending on your budget and what accuracy you trying to achieve, you can try
Commertical OCR - MSDK from ABBYY http://abbyy.com/mobileocr/iphone - high accuracy, customer support, etc. but costs money. Disclaimer: I work for ABBYY
Open Source OCR - Tesseract http://code.google.com/p/tesseract-ocr/ - completely free, but less accurate. This sample shows how to run it on iPhone: https://github.com/nolanbrown/Tesseract-iPhone-Demo
I have used tesseract. Its accuracy ranges from 0-100% depending upon various factors like how well the image is captured,fonts and color of the text etc.
But it can give you very good result if you have a very clear image with very clear text.