Object-Recognition

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Object-Recognition

mat2e
Hi all,

I`m facing a problem that sounds pretty easy but it doesn´t seem to be. I want to find an object (in this example a static text) in an image and rotate, transform it so that it looks like the original. The Text may vary in color or greyscale, but the outlines are stable.

I habe two example images where this
Source Image 
is the image containing the text I´m looking for and this
Template Image
 is the template.

Is there any plugin or a set of plugins which could do the job? I´ve read a lot of stuff on wikipedia but it´s hard to find a good starting point. The template mapping plugin I´ve tried doesn´t get me there.

Thanks for any advice,

mat2e
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Re: Object-Recognition

Stephan Saalfeld
Hi mat2e,

not exactly designed for text-recognition, but in Fiji, I could do it
that way:

Plugins -> Feature Extraction -> Extract SIFT Correspondences

with

Initial gaussina blur: 3.00px
steps per scale octave: 5

Finds some matching interest points that are consistent with a rigid
body transformation.

Use those to transform one image into the other:

Plugins -> Transform -> Landmark Correspondences

SIFT features are not designed for text so I cannot predict how well
they will perform on other images.

Best,
Stephan
 

On Sun, 2010-01-10 at 12:48 -0800, mat2e wrote:

> Hi all,
>
> I`m facing a problem that sounds pretty easy but it doesn´t seem to be. I
> want to find an object (in this example a static text) in an image and
> rotate, transform it so that it looks like the original. The Text may vary
> in color or greyscale, but the outlines are stable.
>
> I habe two example images where this
> http://n2.nabble.com/file/n4282555/pic.png 
> is the image containing the text I´m looking for and this
> http://n2.nabble.com/file/n4282555/template.png 
>  is the template.
>
> Is there any plugin or a set of plugins which could do the job? I´ve read a
> lot of stuff on wikipedia but it´s hard to find a good starting point. The
> template mapping plugin I´ve tried doesn´t get me there.
>
> Thanks for any advice,
>
> mat2e
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Re: Object-Recognition

Gluender-3
In reply to this post by mat2e
mat2e (BTW great name),

I understand that you want to know if a given
text is present in an image. However, the text in
general appears being geometrically transformed
in the image.

Could you be more specific about the kind of
transformations (Shifts, Rotations,
Scale-Changes, Distortions...) that may occur?

>Hi all,
>
>I`m facing a problem that sounds pretty easy but it doesn´t seem to be. I
>want to find an object (in this example a static text) in an image and
>rotate, transform it so that it looks like the original. The Text may vary
>in color or greyscale, but the outlines are stable.
>
>I habe two example images where this
>http://n2.nabble.com/file/n4282555/pic.png
>is the image containing the text I´m looking for and this
>http://n2.nabble.com/file/n4282555/template.png
>  is the template.
>
>Is there any plugin or a set of plugins which could do the job? I´ve read a
>lot of stuff on wikipedia but it´s hard to find a good starting point. The
>template mapping plugin I´ve tried doesn´t get me there.
>
>Thanks for any advice,
>
>mat2e
>--

--
                   Herbie

          ------------------------
          <http://www.gluender.de>
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Re: Object-Recognition

mat2e
In reply to this post by Stephan Saalfeld
Hi Stephan,

sounds great I´ll definately give it a try. Thanks for your help.

mat2e
Stephan Saalfeld wrote
Hi mat2e,

not exactly designed for text-recognition, but in Fiji, I could do it
that way:

Plugins -> Feature Extraction -> Extract SIFT Correspondences

with

Initial gaussina blur: 3.00px
steps per scale octave: 5

Finds some matching interest points that are consistent with a rigid
body transformation.

Use those to transform one image into the other:

Plugins -> Transform -> Landmark Correspondences

SIFT features are not designed for text so I cannot predict how well
they will perform on other images.

Best,
Stephan
 

On Sun, 2010-01-10 at 12:48 -0800, mat2e wrote:
> Hi all,
>
> I`m facing a problem that sounds pretty easy but it doesn´t seem to be. I
> want to find an object (in this example a static text) in an image and
> rotate, transform it so that it looks like the original. The Text may vary
> in color or greyscale, but the outlines are stable.
>
> I habe two example images where this
> http://n2.nabble.com/file/n4282555/pic.png 
> is the image containing the text I´m looking for and this
> http://n2.nabble.com/file/n4282555/template.png 
>  is the template.
>
> Is there any plugin or a set of plugins which could do the job? I´ve read a
> lot of stuff on wikipedia but it´s hard to find a good starting point. The
> template mapping plugin I´ve tried doesn´t get me there.
>
> Thanks for any advice,
>
> mat2e
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Re: Object-Recognition

mat2e
In reply to this post by Gluender-3
Hi Gluender-3,

imagine the text being written on a piece of paper and you take a photo of that (you intend to take a photo of the text). It will for sure be a little rotated, a little distorted and so on but it should not be extremely transformed.

Thanks,

mat2e (It just occured to me as you said it, that the name fits in here quite well...)

Gluender-3 wrote
mat2e (BTW great name),

I understand that you want to know if a given
text is present in an image. However, the text in
general appears being geometrically transformed
in the image.

Could you be more specific about the kind of
transformations (Shifts, Rotations,
Scale-Changes, Distortions...) that may occur?

>Hi all,
>
>I`m facing a problem that sounds pretty easy but it doesn´t seem to be. I
>want to find an object (in this example a static text) in an image and
>rotate, transform it so that it looks like the original. The Text may vary
>in color or greyscale, but the outlines are stable.
>
>I habe two example images where this
>http://n2.nabble.com/file/n4282555/pic.png
>is the image containing the text I´m looking for and this
>http://n2.nabble.com/file/n4282555/template.png
>  is the template.
>
>Is there any plugin or a set of plugins which could do the job? I´ve read a
>lot of stuff on wikipedia but it´s hard to find a good starting point. The
>template mapping plugin I´ve tried doesn´t get me there.
>
>Thanks for any advice,
>
>mat2e
>--

--
                   Herbie

          ------------------------
          <http://www.gluender.de>
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Re: Object-Recognition

Gluender-3
mat2e,

the thing is that if you only have to deal with
shifts, rotations and scale-changes, then there
exist "classic" methods for matching 2D-objects.
If you have to deal with affine transformations
or, even worse, with distortions, then the task
is less easy and in most cases not uniquely to
solve.

In your previously shown images the rotation was
considerable but I couldn't realize any
distortions.

>Hi Gluender-3,
>
>imagine the text being written on a piece of paper and you take a photo of
>that (you intend to take a photo of the text). It will for sure be a little
>rotated, a little distorted and so on but it should not be extremely
>transformed.
>
>Thanks,
>
>mat2e (It just occured to me as you said it, that the name fits in here
>quite well...)
>
>
>Gluender-3 wrote:
>>
>  > mat2e (BTW great name),
>>
>>  I understand that you want to know if a given
>>  text is present in an image. However, the text in
>>  general appears being geometrically transformed
>>  in the image.
>>
>>  Could you be more specific about the kind of
>>  transformations (Shifts, Rotations,
>>  Scale-Changes, Distortions...) that may occur?
>>
>>>Hi all,
>>>
>>>I`m facing a problem that sounds pretty easy but it doesn´t seem to be. I
>>>want to find an object (in this example a static text) in an image and
>>>rotate, transform it so that it looks like the original. The Text may vary
>>>in color or greyscale, but the outlines are stable.
>>>
>>>I habe two example images where this
>>>http://n2.nabble.com/file/n4282555/pic.png
>>>is the image containing the text I´m looking for and this
>>>http://n2.nabble.com/file/n4282555/template.png
>>>   is the template.
>>>
>>>Is there any plugin or a set of plugins which could do the job? I´ve read
>a
>>>lot of stuff on wikipedia but it´s hard to find a good starting point. The
>>>template mapping plugin I´ve tried doesn´t get me there.
>>>
>>>Thanks for any advice,
>>>
>>>mat2e
>  >>--
>  >
>  > --
>  >                    Herbie
>>
>>            ------------------------
>  >           <http://www.gluender.de>

Best
--

                   Herbie

          ------------------------
          <http://www.gluender.de>
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Re: Object-Recognition

David Webster
In reply to this post by mat2e
All,

You can even handle affine transformations if you can find software to do
Geometrical Indexing/Hashing (see Wikipedia).

Generally, the classic methods also only work well for cases wth no
occlusion, fairly good image quality, minimal in class variation, and small
numbers of classes.

David Webtser

On Mon, Jan 11, 2010 at 11:54 AM, Gluender <[hidden email]> wrote:

> mat2e,
>
> the thing is that if you only have to deal with shifts, rotations and
> scale-changes, then there exist "classic" methods for matching 2D-objects.
> If you have to deal with affine transformations or, even worse, with
> distortions, then the task is less easy and in most cases not uniquely to
> solve.
>
> In your previously shown images the rotation was considerable but I
> couldn't realize any distortions.
>
>
> Hi Gluender-3,
>>
>> imagine the text being written on a piece of paper and you take a photo of
>> that (you intend to take a photo of the text). It will for sure be a
>> little
>> rotated, a little distorted and so on but it should not be extremely
>> transformed.
>>
>> Thanks,
>>
>> mat2e (It just occured to me as you said it, that the name fits in here
>> quite well...)
>>
>>
>> Gluender-3 wrote:
>>
>>>
>>>  > mat2e (BTW great name),
>>
>>>
>>>  I understand that you want to know if a given
>>>  text is present in an image. However, the text in
>>>  general appears being geometrically transformed
>>>  in the image.
>>>
>>>  Could you be more specific about the kind of
>>>  transformations (Shifts, Rotations,
>>>  Scale-Changes, Distortions...) that may occur?
>>>
>>> Hi all,
>>>>
>>>> I`m facing a problem that sounds pretty easy but it doesn´t seem to be.
>>>> I
>>>> want to find an object (in this example a static text) in an image and
>>>> rotate, transform it so that it looks like the original. The Text may
>>>> vary
>>>> in color or greyscale, but the outlines are stable.
>>>>
>>>> I habe two example images where this
>>>> http://n2.nabble.com/file/n4282555/pic.png
>>>> is the image containing the text I´m looking for and this
>>>> http://n2.nabble.com/file/n4282555/template.png
>>>>  is the template.
>>>>
>>>> Is there any plugin or a set of plugins which could do the job? I´ve
>>>> read
>>>>
>>> a
>>
>>> lot of stuff on wikipedia but it´s hard to find a good starting point.
>>>> The
>>>> template mapping plugin I´ve tried doesn´t get me there.
>>>>
>>>> Thanks for any advice,
>>>>
>>>> mat2e
>>>>
>>>  >>--
>>  >
>>  > --
>>  >                    Herbie
>>
>>>
>>>           ------------------------
>>>
>>  >           <http://www.gluender.de>
>>
>
> Best
> --
>
>                  Herbie
>
>         ------------------------
>         <http://www.gluender.de>
>