Image processing of Synoptic Charts

I need advice on the processing and data extraction from the image of a synoptic chart.

The code needs to determine the location of the high pressure (H) and low pressure (L) regions on the chart.

I have used the ocr commands, but it is not picking up the H and L text in the image.

I used a code similar to the one provided here: https://uk.mathworks.com/matlabcentral/answers/183922-unable-to-recognize-letter-labels-in-a-image-using-ocr-function. This picks up the numbers as letters as well.

Answer 1

[Anshika Chaurasia]

Hi Madeleine,

It is my understanding on using this answer code the ocr is recognizing numbers(0-9) as letters(A-Z).

One possible reason could be that in ocr, 'CharacterSet' is set to 'A:Z'. In this case, the ocr attempts to match each character to only letters.

results = ocr(BW1, roi, 'TextLayout', 'Word','CharacterSet','A':'Z');

Try to use ocr without CharacterSet Name-Value pair argument and check the result.

Refer to CharacterSet documentation for more information.

Hope it helps!