Rendering character

[Urvish]

Hi,

i am using gdpicture versin 9.0.
i am unable to recognize character with blur and dotted background in my pdf.
can u please suggest me wht to do?

[Loïc]

Hello,

Could you attach an image as example?

Kind regards,

Loïc

[Urvish]

Hi,
I have attach my image

Thanks,
Urvish

[Loïc]

Hello,

Unfortunately there is definitively nothing we can do to correctly OCR such image.

Kind regards,

Loïc

[Urvish]

Hi,

Thank u very much loic for ur reply.
is ther any other way if u can suggest me?

Kind regards,
Urvish

[Loïc]

Hello Urvish,

The better quality I've been able to obtain is by combining upscalling and adaptive threshold in this way:

Code: Select all

GdPictureImaging.Scale(ImageID, 1000, Drawing2D.InterpolationMode.HighQualityBicubic)
GdPictureImaging.ConvertTo1BppAT(ImageID, 30)

Unfortunately, this is probably not enough for OCR purpose. There is 3 major issues with your image:

- It has been produced in low resolution.
- The background can not be correctly extracted from the foreground. I've tried many pre-filtering plus all existing adaptive thresholding mechanism with no success.
- It is almost impossible to recover all characters contours. This is due to the background pattern which has the same luminosity and saturation as the chars.

Basically an extreme solution would consist to write an algorithm, dedicated for this kind of image, that would be able to remove the background pattern, rebuild the characters contours and threshold the result to a highest resolution bitmap. If you are able to write such function, new problem will come: You will not find any OCR engine that will be able to provide accurate result on your bitmap since the produced characters will contain too much variation.

I am maybe wrong, but based on my experience on similar challenges (my job for 6 years), I don't see any suitable procedure to provide accurate results without a checksum mechanism or a database containing all possible occurrence plus an ICR engine providing a voting mechanism.

With best regards,

Loïc

[Urvish]

Hi,

Thank you very much loic for your suggestions and fast reply.

Thanks,
Urvish

[Loïc]

You're welcome!

[Urvish]

Hi Loic,

I am using GdPicture Version 9.0
I want to create new pdf from my existing pdf.
Iwant to render all the text and image from it and write it to new pdf file.
how can i create it using gdpicture?
can u help me out for this?


Thanks,
Urvish

[Loïc]

Hello Urvish,

Please try to create a standalone ticket into the appropriated subforum for any new request.

Thank you for your understanding.

With best regards,

Loïc

[Urvish]

Hi,

Ok.
No Problem.

Thanks,
Urvish