RSS News FeedHide an image inside an image
Message-ID:<ec9010c5-77ef-494a-ab51-1f1a1e8fcc5e@o4g2000pra.googlegroups.com>
Subject:
Hide an image inside an image
Date:Fri, 12 Dec 2008 21:35:52 +0100
Hi, I hope I can correctly describe what I would like to do. I want to merge image A into image B. If you look at the result you will only see image B. But if you use a colored filter (e.g. a red foil/filter or red glasses) you will see image A into image B. Maybe you remember some kind of paper copy protection from computer games 20 years ago. They had some kind of printed copy protection where you need to input some code into the game to proceed. Some printed protection where only visible with a red film. How can I do something like that with gimp? Thanks & regards Poncho
Message-ID:<6qhlidFcc9m9U1@mid.individual.net>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 12:45:17 +0100
poncho schrieb: > Hi, > I hope I can correctly describe what I would like to do. > > I want to merge image A into image B. If you look at the result you > will only see image B. > But if you use a colored filter (e.g. a red foil/filter or red > glasses) you will see image A into image B. > > Maybe you remember some kind of paper copy protection from computer > games 20 years ago. > They had some kind of printed copy protection where you need to input > some code into the game > to proceed. Some printed protection where only visible with a red > film. > > How can I do something like that with gimp? Look for the steganography plugin. HTH, Frank
Message-ID:<95O0l.18277$Ax1.15343@newsfe29.ams2>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 13:42:45 +0100
On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > poncho schrieb: >> Hi, >> I hope I can correctly describe what I would like to do. >> >> I want to merge image A into image B. If you look at the result you >> will only see image B. >> But if you use a colored filter (e.g. a red foil/filter or red glasses) >> you will see image A into image B. >> >> Maybe you remember some kind of paper copy protection from computer >> games 20 years ago. >> They had some kind of printed copy protection where you need to input >> some code into the game >> to proceed. Some printed protection where only visible with a red film. >> >> How can I do something like that with gimp? > > Look for the steganography plugin. > > HTH, > Frank As I read the OP its not about encryption ie. hiding one file inside another. Its more along the lines of the colour blindness test cards where some images are not visible because the viewer cannot see red or green etc. I would think that I you took an image that is predominantly blue and green then added the "code" in red you would get something like the OP requires. Needs some experimentation I think. -- rich
Message-ID:<OMO0l.65894$Nq1.58774@newsfe10.ams2>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 14:29:18 +0100
On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > >> poncho schrieb: >>> Hi, >>> I hope I can correctly describe what I would like to do. >>> >>> I want to merge image A into image B. If you look at the result you >>> will only see image B. >>> But if you use a colored filter (e.g. a red foil/filter or red >>> glasses) you will see image A into image B. >>> >>> Maybe you remember some kind of paper copy protection from computer >>> games 20 years ago. >>> They had some kind of printed copy protection where you need to input >>> some code into the game >>> to proceed. Some printed protection where only visible with a red >>> film. >>> >>> How can I do something like that with gimp? >> >> Look for the steganography plugin. >> >> HTH, >> Frank > > As I read the OP its not about encryption ie. hiding one file inside > another. > > Its more along the lines of the colour blindness test cards where some > images are not visible because the viewer cannot see red or green etc. > > I would think that I you took an image that is predominantly blue and > green then added the "code" in red you would get something like the OP > requires. Needs some experimentation I think. Just a very quick test I took a standard ishihara chart added a couple of semi-opaque layers. the result is here http://rapidshare.com/files/172974974/test.xcf If you toggle the first layer on and off, replicating looking through a filter then you should see a result. Needs a lot more experimenting. -- rich
Message-ID:<VdS0l.159$hs1.155@newsfe04.iad>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 18:25:09 +0100
On Sat, 13 Dec 2008 13:29:18 +0000, rich wrote: > On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > >> On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: >> >>> poncho schrieb: >>>> Hi, >>>> I hope I can correctly describe what I would like to do. >>>> >>>> I want to merge image A into image B. If you look at the result you >>>> will only see image B. >>>> But if you use a colored filter (e.g. a red foil/filter or red >>>> glasses) you will see image A into image B. >>>> >>>> Maybe you remember some kind of paper copy protection from computer >>>> games 20 years ago. >>>> They had some kind of printed copy protection where you need to input >>>> some code into the game >>>> to proceed. Some printed protection where only visible with a red >>>> film. >>>> >>>> How can I do something like that with gimp? >>> >>> Look for the steganography plugin. >>> >>> HTH, >>> Frank >> >> As I read the OP its not about encryption ie. hiding one file inside >> another. >> >> Its more along the lines of the colour blindness test cards where some >> images are not visible because the viewer cannot see red or green etc. >> >> I would think that I you took an image that is predominantly blue and >> green then added the "code" in red you would get something like the OP >> requires. Needs some experimentation I think. > > Just a very quick test > I took a standard ishihara chart added a couple of semi-opaque layers. > the result is here > http://rapidshare.com/files/172974974/test.xcf > > If you toggle the first layer on and off, replicating looking through a > filter then you should see a result. Needs a lot more experimenting. * * * Rich, I would think this is a simple form of steganography, using a single color filter for a coding/decoding device... JR the postman
Message-ID:<fe37f5ec-0ea0-4e83-8807-0611334dbff4@r24g2000vbp.googlegroups.com>
Subject:
Re: Hide an image inside an image
Date:Mon, 15 Dec 2008 07:52:15 +0100
On 13 Dez., 18:25, Postman Delivers <JR_the_Post...@xyzahoo.com> wrote: > On Sat, 13 Dec 2008 13:29:18 +0000, rich wrote: > > On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > > >> On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > > >>> poncho schrieb: > >>>> Hi, > >>>> I hope I can correctly describe what I would like to do. > > >>>> I want to merge image A into image B. If you look at the result you > >>>> will only see image B. > >>>> But if you use a colored filter (e.g. a red foil/filter or red > >>>> glasses) you will see image A into image B. > > >>>> Maybe you remember some kind of paper copy protection from computer > >>>> games 20 years ago. > >>>> They had some kind of printed copy protection where you need to input > >>>> some code into the game > >>>> to proceed. Some printed protection where only visible with a red > >>>> film. > > >>>> How can I do something like that with gimp? > > >>> Look for the steganography plugin. > > >>> HTH, > >>> Frank > > >> As I read the OP its not about encryption ie. hiding one file inside > >> another. > > >> Its more along the lines of the colour blindness test cards where some > >> images are not visible because the viewer cannot see red or green etc. > > >> I would think that I you took an image that is predominantly blue and > >> green then added the "code" in red you would get something like the OP > >> requires. Needs some experimentation I think. > > > Just a very quick test > > I took a standard ishihara chart added a couple of semi-opaque layers. > > the result is here > >http://rapidshare.com/files/172974974/test.xcf > > > If you toggle the first layer on and off, replicating looking through a > > filter then you should see a result. Needs a lot more experimenting. > > * * * > Rich, > > I would think this is a simple form of steganography, using a single > color filter for a coding/decoding device... > > JR the postman Hi, thanks for all your posts. I still haven't reached the solution I'd like to have. But maybe I can describe it a litte bit better now. @rich: You're right. My first hits when I tried to "google" for my problem were about steganography". But this is not what I am looking for. The picture inside should only be hidden by a simple way, so that you can find it by using any red-foil or something (any other color would do, too) I heared by somebody, that it should be easier if you can hide image A inside image B in an area with a lot of "noise", which would be fine with me. (e.g. A picture with bushes or a forrest where you can hide img A) BTW image A can be a simple image, like a symbol, or just a letter. So, these are my requirements: Hide image A inside image B image A can't be seen for a person image A can be seen if a person uses a red foil as a filter image A can be a simple image (like symbol or a character) Regards Poncho
Message-ID:<ec9010c5-77ef-494a-ab51-1f1a1e8fcc5e@o4g2000pra.googlegroups.com>
Subject:
Hide an image inside an image
Date:Fri, 12 Dec 2008 21:35:52 +0100
Hi, I hope I can correctly describe what I would like to do. I want to merge image A into image B. If you look at the result you will only see image B. But if you use a colored filter (e.g. a red foil/filter or red glasses) you will see image A into image B. Maybe you remember some kind of paper copy protection from computer games 20 years ago. They had some kind of printed copy protection where you need to input some code into the game to proceed. Some printed protection where only visible with a red film. How can I do something like that with gimp? Thanks & regards Poncho
Message-ID:<6qhlidFcc9m9U1@mid.individual.net>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 12:45:17 +0100
poncho schrieb: > Hi, > I hope I can correctly describe what I would like to do. > > I want to merge image A into image B. If you look at the result you > will only see image B. > But if you use a colored filter (e.g. a red foil/filter or red > glasses) you will see image A into image B. > > Maybe you remember some kind of paper copy protection from computer > games 20 years ago. > They had some kind of printed copy protection where you need to input > some code into the game > to proceed. Some printed protection where only visible with a red > film. > > How can I do something like that with gimp? Look for the steganography plugin. HTH, Frank
Message-ID:<95O0l.18277$Ax1.15343@newsfe29.ams2>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 13:42:45 +0100
On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > poncho schrieb: >> Hi, >> I hope I can correctly describe what I would like to do. >> >> I want to merge image A into image B. If you look at the result you >> will only see image B. >> But if you use a colored filter (e.g. a red foil/filter or red glasses) >> you will see image A into image B. >> >> Maybe you remember some kind of paper copy protection from computer >> games 20 years ago. >> They had some kind of printed copy protection where you need to input >> some code into the game >> to proceed. Some printed protection where only visible with a red film. >> >> How can I do something like that with gimp? > > Look for the steganography plugin. > > HTH, > Frank As I read the OP its not about encryption ie. hiding one file inside another. Its more along the lines of the colour blindness test cards where some images are not visible because the viewer cannot see red or green etc. I would think that I you took an image that is predominantly blue and green then added the "code" in red you would get something like the OP requires. Needs some experimentation I think. -- rich
Message-ID:<OMO0l.65894$Nq1.58774@newsfe10.ams2>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 14:29:18 +0100
On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > >> poncho schrieb: >>> Hi, >>> I hope I can correctly describe what I would like to do. >>> >>> I want to merge image A into image B. If you look at the result you >>> will only see image B. >>> But if you use a colored filter (e.g. a red foil/filter or red >>> glasses) you will see image A into image B. >>> >>> Maybe you remember some kind of paper copy protection from computer >>> games 20 years ago. >>> They had some kind of printed copy protection where you need to input >>> some code into the game >>> to proceed. Some printed protection where only visible with a red >>> film. >>> >>> How can I do something like that with gimp? >> >> Look for the steganography plugin. >> >> HTH, >> Frank > > As I read the OP its not about encryption ie. hiding one file inside > another. > > Its more along the lines of the colour blindness test cards where some > images are not visible because the viewer cannot see red or green etc. > > I would think that I you took an image that is predominantly blue and > green then added the "code" in red you would get something like the OP > requires. Needs some experimentation I think. Just a very quick test I took a standard ishihara chart added a couple of semi-opaque layers. the result is here http://rapidshare.com/files/172974974/test.xcf If you toggle the first layer on and off, replicating looking through a filter then you should see a result. Needs a lot more experimenting. -- rich
Message-ID:<VdS0l.159$hs1.155@newsfe04.iad>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 18:25:09 +0100
On Sat, 13 Dec 2008 13:29:18 +0000, rich wrote: > On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > >> On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: >> >>> poncho schrieb: >>>> Hi, >>>> I hope I can correctly describe what I would like to do. >>>> >>>> I want to merge image A into image B. If you look at the result you >>>> will only see image B. >>>> But if you use a colored filter (e.g. a red foil/filter or red >>>> glasses) you will see image A into image B. >>>> >>>> Maybe you remember some kind of paper copy protection from computer >>>> games 20 years ago. >>>> They had some kind of printed copy protection where you need to input >>>> some code into the game >>>> to proceed. Some printed protection where only visible with a red >>>> film. >>>> >>>> How can I do something like that with gimp? >>> >>> Look for the steganography plugin. >>> >>> HTH, >>> Frank >> >> As I read the OP its not about encryption ie. hiding one file inside >> another. >> >> Its more along the lines of the colour blindness test cards where some >> images are not visible because the viewer cannot see red or green etc. >> >> I would think that I you took an image that is predominantly blue and >> green then added the "code" in red you would get something like the OP >> requires. Needs some experimentation I think. > > Just a very quick test > I took a standard ishihara chart added a couple of semi-opaque layers. > the result is here > http://rapidshare.com/files/172974974/test.xcf > > If you toggle the first layer on and off, replicating looking through a > filter then you should see a result. Needs a lot more experimenting. * * * Rich, I would think this is a simple form of steganography, using a single color filter for a coding/decoding device... JR the postman
Message-ID:<fe37f5ec-0ea0-4e83-8807-0611334dbff4@r24g2000vbp.googlegroups.com>
Subject:
Re: Hide an image inside an image
Date:Mon, 15 Dec 2008 07:52:15 +0100
On 13 Dez., 18:25, Postman Delivers <JR_the_Post...@xyzahoo.com> wrote: > On Sat, 13 Dec 2008 13:29:18 +0000, rich wrote: > > On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > > >> On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > > >>> poncho schrieb: > >>>> Hi, > >>>> I hope I can correctly describe what I would like to do. > > >>>> I want to merge image A into image B. If you look at the result you > >>>> will only see image B. > >>>> But if you use a colored filter (e.g. a red foil/filter or red > >>>> glasses) you will see image A into image B. > > >>>> Maybe you remember some kind of paper copy protection from computer > >>>> games 20 years ago. > >>>> They had some kind of printed copy protection where you need to input > >>>> some code into the game > >>>> to proceed. Some printed protection where only visible with a red > >>>> film. > > >>>> How can I do something like that with gimp? > > >>> Look for the steganography plugin. > > >>> HTH, > >>> Frank > > >> As I read the OP its not about encryption ie. hiding one file inside > >> another. > > >> Its more along the lines of the colour blindness test cards where some > >> images are not visible because the viewer cannot see red or green etc. > > >> I would think that I you took an image that is predominantly blue and > >> green then added the "code" in red you would get something like the OP > >> requires. Needs some experimentation I think. > > > Just a very quick test > > I took a standard ishihara chart added a couple of semi-opaque layers. > > the result is here > >http://rapidshare.com/files/172974974/test.xcf > > > If you toggle the first layer on and off, replicating looking through a > > filter then you should see a result. Needs a lot more experimenting. > > * * * > Rich, > > I would think this is a simple form of steganography, using a single > color filter for a coding/decoding device... > > JR the postman Hi, thanks for all your posts. I still haven't reached the solution I'd like to have. But maybe I can describe it a litte bit better now. @rich: You're right. My first hits when I tried to "google" for my problem were about steganography". But this is not what I am looking for. The picture inside should only be hidden by a simple way, so that you can find it by using any red-foil or something (any other color would do, too) I heared by somebody, that it should be easier if you can hide image A inside image B in an area with a lot of "noise", which would be fine with me. (e.g. A picture with bushes or a forrest where you can hide img A) BTW image A can be a simple image, like a symbol, or just a letter. So, these are my requirements: Hide image A inside image B image A can't be seen for a person image A can be seen if a person uses a red foil as a filter image A can be a simple image (like symbol or a character) Regards Poncho
Message-ID:<ec9010c5-77ef-494a-ab51-1f1a1e8fcc5e@o4g2000pra.googlegroups.com>
Subject:
Hide an image inside an image
Date:Fri, 12 Dec 2008 21:35:52 +0100
Hi, I hope I can correctly describe what I would like to do. I want to merge image A into image B. If you look at the result you will only see image B. But if you use a colored filter (e.g. a red foil/filter or red glasses) you will see image A into image B. Maybe you remember some kind of paper copy protection from computer games 20 years ago. They had some kind of printed copy protection where you need to input some code into the game to proceed. Some printed protection where only visible with a red film. How can I do something like that with gimp? Thanks & regards Poncho
Message-ID:<6qhlidFcc9m9U1@mid.individual.net>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 12:45:17 +0100
poncho schrieb: > Hi, > I hope I can correctly describe what I would like to do. > > I want to merge image A into image B. If you look at the result you > will only see image B. > But if you use a colored filter (e.g. a red foil/filter or red > glasses) you will see image A into image B. > > Maybe you remember some kind of paper copy protection from computer > games 20 years ago. > They had some kind of printed copy protection where you need to input > some code into the game > to proceed. Some printed protection where only visible with a red > film. > > How can I do something like that with gimp? Look for the steganography plugin. HTH, Frank
Message-ID:<95O0l.18277$Ax1.15343@newsfe29.ams2>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 13:42:45 +0100
On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > poncho schrieb: >> Hi, >> I hope I can correctly describe what I would like to do. >> >> I want to merge image A into image B. If you look at the result you >> will only see image B. >> But if you use a colored filter (e.g. a red foil/filter or red glasses) >> you will see image A into image B. >> >> Maybe you remember some kind of paper copy protection from computer >> games 20 years ago. >> They had some kind of printed copy protection where you need to input >> some code into the game >> to proceed. Some printed protection where only visible with a red film. >> >> How can I do something like that with gimp? > > Look for the steganography plugin. > > HTH, > Frank As I read the OP its not about encryption ie. hiding one file inside another. Its more along the lines of the colour blindness test cards where some images are not visible because the viewer cannot see red or green etc. I would think that I you took an image that is predominantly blue and green then added the "code" in red you would get something like the OP requires. Needs some experimentation I think. -- rich
Message-ID:<OMO0l.65894$Nq1.58774@newsfe10.ams2>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 14:29:18 +0100
On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > >> poncho schrieb: >>> Hi, >>> I hope I can correctly describe what I would like to do. >>> >>> I want to merge image A into image B. If you look at the result you >>> will only see image B. >>> But if you use a colored filter (e.g. a red foil/filter or red >>> glasses) you will see image A into image B. >>> >>> Maybe you remember some kind of paper copy protection from computer >>> games 20 years ago. >>> They had some kind of printed copy protection where you need to input >>> some code into the game >>> to proceed. Some printed protection where only visible with a red >>> film. >>> >>> How can I do something like that with gimp? >> >> Look for the steganography plugin. >> >> HTH, >> Frank > > As I read the OP its not about encryption ie. hiding one file inside > another. > > Its more along the lines of the colour blindness test cards where some > images are not visible because the viewer cannot see red or green etc. > > I would think that I you took an image that is predominantly blue and > green then added the "code" in red you would get something like the OP > requires. Needs some experimentation I think. Just a very quick test I took a standard ishihara chart added a couple of semi-opaque layers. the result is here http://rapidshare.com/files/172974974/test.xcf If you toggle the first layer on and off, replicating looking through a filter then you should see a result. Needs a lot more experimenting. -- rich
Message-ID:<VdS0l.159$hs1.155@newsfe04.iad>
Subject:
Re: Hide an image inside an image
Date:Sat, 13 Dec 2008 18:25:09 +0100
On Sat, 13 Dec 2008 13:29:18 +0000, rich wrote: > On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > >> On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: >> >>> poncho schrieb: >>>> Hi, >>>> I hope I can correctly describe what I would like to do. >>>> >>>> I want to merge image A into image B. If you look at the result you >>>> will only see image B. >>>> But if you use a colored filter (e.g. a red foil/filter or red >>>> glasses) you will see image A into image B. >>>> >>>> Maybe you remember some kind of paper copy protection from computer >>>> games 20 years ago. >>>> They had some kind of printed copy protection where you need to input >>>> some code into the game >>>> to proceed. Some printed protection where only visible with a red >>>> film. >>>> >>>> How can I do something like that with gimp? >>> >>> Look for the steganography plugin. >>> >>> HTH, >>> Frank >> >> As I read the OP its not about encryption ie. hiding one file inside >> another. >> >> Its more along the lines of the colour blindness test cards where some >> images are not visible because the viewer cannot see red or green etc. >> >> I would think that I you took an image that is predominantly blue and >> green then added the "code" in red you would get something like the OP >> requires. Needs some experimentation I think. > > Just a very quick test > I took a standard ishihara chart added a couple of semi-opaque layers. > the result is here > http://rapidshare.com/files/172974974/test.xcf > > If you toggle the first layer on and off, replicating looking through a > filter then you should see a result. Needs a lot more experimenting. * * * Rich, I would think this is a simple form of steganography, using a single color filter for a coding/decoding device... JR the postman
Message-ID:<fe37f5ec-0ea0-4e83-8807-0611334dbff4@r24g2000vbp.googlegroups.com>
Subject:
Re: Hide an image inside an image
Date:Mon, 15 Dec 2008 07:52:15 +0100
On 13 Dez., 18:25, Postman Delivers <JR_the_Post...@xyzahoo.com> wrote: > On Sat, 13 Dec 2008 13:29:18 +0000, rich wrote: > > On Sat, 13 Dec 2008 12:42:45 +0000, rich wrote: > > >> On Sat, 13 Dec 2008 12:45:17 +0100, Fr@nk Stef@ni wrote: > > >>> poncho schrieb: > >>>> Hi, > >>>> I hope I can correctly describe what I would like to do. > > >>>> I want to merge image A into image B. If you look at the result you > >>>> will only see image B. > >>>> But if you use a colored filter (e.g. a red foil/filter or red > >>>> glasses) you will see image A into image B. > > >>>> Maybe you remember some kind of paper copy protection from computer > >>>> games 20 years ago. > >>>> They had some kind of printed copy protection where you need to input > >>>> some code into the game > >>>> to proceed. Some printed protection where only visible with a red > >>>> film. > > >>>> How can I do something like that with gimp? > > >>> Look for the steganography plugin. > > >>> HTH, > >>> Frank > > >> As I read the OP its not about encryption ie. hiding one file inside > >> another. > > >> Its more along the lines of the colour blindness test cards where some > >> images are not visible because the viewer cannot see red or green etc. > > >> I would think that I you took an image that is predominantly blue and > >> green then added the "code" in red you would get something like the OP > >> requires. Needs some experimentation I think. > > > Just a very quick test > > I took a standard ishihara chart added a couple of semi-opaque layers. > > the result is here > >http://rapidshare.com/files/172974974/test.xcf > > > If you toggle the first layer on and off, replicating looking through a > > filter then you should see a result. Needs a lot more experimenting. > > * * * > Rich, > > I would think this is a simple form of steganography, using a single > color filter for a coding/decoding device... > > JR the postman Hi, thanks for all your posts. I still haven't reached the solution I'd like to have. But maybe I can describe it a litte bit better now. @rich: You're right. My first hits when I tried to "google" for my problem were about steganography". But this is not what I am looking for. The picture inside should only be hidden by a simple way, so that you can find it by using any red-foil or something (any other color would do, too) I heared by somebody, that it should be easier if you can hide image A inside image B in an area with a lot of "noise", which would be fine with me. (e.g. A picture with bushes or a forrest where you can hide img A) BTW image A can be a simple image, like a symbol, or just a letter. So, these are my requirements: Hide image A inside image B image A can't be seen for a person image A can be seen if a person uses a red foil as a filter image A can be a simple image (like symbol or a character) Regards Poncho