Incorrect deskewing of image

[RashmiPandeyatGit]

Incorrect deskewing of image

[kakul]

Is this the given initial image, or image generated after deskew?

[kakul]

Could you attach the initial image?

Probably the circles in the image are creating problems with hough transform calculations.

[kakul]

Ok will try and let you know soon

[kakul]

Yes

[kakul]

It worked correctly on the given image, without anything extra.

[kakul]

Follow these steps:

pip install virtualenv (use sudo if required)

virtualenv any-name-of-your-choice
cd any-name-of-your-choice
pip install alyn

create a file test.py or simply open python interpreter and write the following code:

from alyn import *

d = Deskew(input_file='input.jpg', display='Y', output_file='output.jpg', r_angle=0)
d.deskew()

The output will be saved as output.jpg, once you close the preview display window

[kakul]

In that case you will have to tweak the code a bit, change the default values that are used in skew angle calculation in skew_detect.py. You can supply your own values for sigma and number of peaks or modify the defaults in the code itself.

[kakul]

Try this for different values of sigma and number of peaks to find a fit that works best.

[RashmiPandeyatGit]

from alyn import *

d = Deskew(input_file='input.jpg', display='Y', output_file='output.jpg', r_angle=0)
d.deskew()

In this case error is generated.
from skimage.feature import canny
ImportError: cannot import name canny

[kakul]

Use skimage version >= 0.11

[kakul]

@Rashmi002 did the skew detect parameters work?

[RashmiPandeyatGit]

I am using skimage 0.13 version. How can i know skew detect parameter is working or not?

[RashmiPandeyatGit]

skew detect parameter is not working properly.

[RashmiPandeyatGit]

how can i finetune it?

[kakul]

https://github.com/kakul/Alyn/blob/master/alyn/skew_detect.py#L23
https://github.com/kakul/Alyn/blob/master/alyn/skew_detect.py#L25

Change these values.

[RashmiPandeyatGit]

ok..I will let you know. Thanks for immediate response.

[kakul]

Hi @Rashmi002, did the code work?

[kakul]

Closing this.

[pharrellyhy]

Hi,
I've played around deskew for a while and found if the image contains not only text but also picture, it didn't work well. One workaround is I can crop the region which only contains text. This solution may not work well too since I don't know which part of image contains only text. Do you have any idea on this situation? Below is my test image:

[pharrellyhy]

I also noticed that if the image contains more than one page, like the one I attached above, deskew will fail.