Tesseract training image by image - tesseract

Is there any simple way to train tesseract by giving from command line image and letter that it corresponds to? I know that there are some application that make tesseract learning easier, but I need a custom one, one image - one letter. Of course there may be few images of same letter.

Related

Ai used for recognizing emojis on wallpaper

I want to build an app that will recognize what emojis have been used on the wallpaper.
So for instance this app will receive on input:
And on output should array of names of recognizing emojis return:
[
"Smiling Face with Sunglasses",
"Grinning Face with Smiling Eyes",
"Kissing Face with Closed Eyes"
]
Of course, the names of these emojis will come from the names of files of training images.
For example this file:
It will be called Grinning_Face_with_Smiling_Eyes.jpg
I would like to use AWS Rekognition Label or Google AutoML Vision, but they require a minimum of 10 images of each emoji for training.
As you know, I can only provide one image of each emoji, because there is no more option, they are in 2D ;)
Now my question is:
What should I do? How can I skip these requirements? Which service should I choose?
PS. In real business instead of emojis, there are covers of the books, which AI has to recognize. There is also one image per book-cover photo in 2D.

Tesseract for logos and Fonts

There are some logos for which OCR needs to be run . Logos generally have different fonts. A sample is below. When tesseract was run with all possible psm values RITZ is not getting detected. Also tried converting to black and white using cv2.threshold(grayImage, 120, 255, cv2.THRESH_BINARY) still the R is not getting detected. Can someone tell what technique to be done for these strange fonts. ( I am using python)
It is a problem with tessaract it cant detect complex or handwritten characters. We can use tesseract for simple printed character detection. For complex or handwritten you can try CNN or KNN aalgorithm trained under dataset.(chars74k, A-Z Handwritting)

How to get region of interest in images

I need to train R-CNN on my dataset. Above Image is an example in which first column contain path to that image and second column contain coordinates of bounded box(ROI). How to get those coordinates in matlab. As my dataset is large so how those coordinates can be extracted by pointing manually.
for example if i am training R-CNN foe stop signs then second column contain coordinates of bounded box containing stop sign in whole image.
I do not know which version of MATLAB you are running, but I'm assuming it is fairly new (R2017a and later). Also, by 'how to get the coordinates', I assume you mean 'how to determine' or 'how to assign' the coordinates.
I believe what you need to do is to use one of the image labeling Apps called
imageLabeler
to annotate rectangles in your training images. You either do this manually if that's amenable, or you need to use automation algorithms if you already have a detector that does something similar. See this page for more details:
https://www.mathworks.com/help/vision/ug/create-and-import-an-automation-algorithm-for-ground-truth-labeling.html
Once you have the results of labeling stored in a groundTruth object, you would need to use something like objectDetectorTrainingData to create the table you are looking for.
See https://www.mathworks.com/help/vision/ug/train-an-object-detector-from-ground-truth-data.html for more details.

How to manually segment and label ROIs in an image in Matlab?

I'm a newbie to Matlab. I'm basically attempting to manually segment a set of images and then manually label those segments also. I looked into the imfreehand(), but I'm unable to do this using imfreehand().
Basically, I want to follow the following steps :
Manually segment various ROIs on the image (imfreehand only lets me draw one segment I think?)
Assign labels to all those segments
Save the segments and corresponding labels to be used further (not sure what format they would be stored in, I think imfreehand would give me the position and I could store that along with the labels?)
Hopefully use these labelled segments in the images to form a training dataset for a neural network.
If there is some other tool or software which would help me do this, then any pointers would be very much appreciated. (Also I am new to stackoverflow, so if there is any way I could improve on the question to make it clearer, please let me know!) Thanks!
Derek Hoiem, a computer vision research at the University of Illinois, wrote an object labelling tool which does pretty much exactly what you asked for. You can download it from his page:
http://www.cs.illinois.edu/homes/dhoiem/software/index.html

How to get coordinates of recognized characters

I have a very simple OCR app based on Tesseract. After the recognition
step, I also provide a user verification step that allows correction
in case OCR is wrong. To improve the user interface, I plan to draw a
rectangle on top of the OCR-ed character on the original input image,
and put it side by side with the OCR output. To get to that, I need
the coordinate of the recognized characters.
I tried something like this but it seems to give me gibberish:
ETEXT_DESC output;
tess->Recognize(&output);
text = tess->GetUTF8Text();
Now if I access output->count, it gives me some value above 10,000,
which is obviously wrong because the whole image only has 20 or so characters.
Am I on the right track? Can I have some direction please?
Maybe it's helpful to get the coordinates of the boxes.
Try the executable of tesseract. Use the command
"tesseract.exe [image] [output] makebox"
Afterall you get the coordinates of each character, one per row. Then you are able to compare.
The tesseract executable has an option hocr to output recognized characters and their coordiantes in html format. To get this programmatically, the FAQ says to refer to baseapi.h.