Reading mode: Light Dark

crazy idea? or could this work....

  • Thread starter Thread starter Alfred
  • Start date Start date
Go to last post
A

Alfred

Guest
Hi there, i do have a problem with hot-pixels and i came up with a nice idea... anybody care to comment if it would work or not????

here i go...

lets assume i have a hotpixel (bright purple). In the below "graph" the hotpixel would be the "x" ... and all the other pixels are depicted by "."

Here is my ( simplified ) example:

Lets assume i take a foto of a green background. all of the "." would be green, except for the "x" which would be bright purple (in my case)...

.....
.X..
.....

I do know the X/Y coordinates of the hot pixel (from one of the hotpixel detection programs) ... wouldnt it be possible to write a small photoshop macro to read the color values of the pixel around the hotpixel and AUTOMATICALLY change the color of the hotpixel to the color of the neighbour-pixels? (The idea is to move all photos into a folder and have the macro change the color of the "X" to the colour of the neighbour pixels AUTOMATICALLY).

I am aware that there are hotpixel programs, but the DO NOT KNOW where the hotpixel is, thus have to "guess" by using smart algorithms where a pixel is a hotpixel... but the truth is... WE ALL KNOW WHERE OUR hotpixels are....

does this make sense? I agree it is a simplified example, but i wanted to present the "BIG" idea, rather than discuss what happens if every neighbour has a diferent color.

please feel encouraged to let any comments, i can´t write this program, but i guess it would be a very simple routine, starting with ingressing the coordinates of hot pixels, and leaving unchanged 99.9999% of the other pixels ... or am i to optimistic?

thx for your time
alfred
 
It's a very good idea and some cameras already do it. It's called pixel mapping.

There's a little progam that'll do it for you it's called Thumber. I'd give you the link but they are having problems with thier site at the moment.

Sorry if this is disappointing but it least it proves your idea was good and you were right.
regards
Ian
Alfred said:
Hi there, i do have a problem with hot-pixels and i came up with a
nice idea... anybody care to comment if it would work or not????

here i go...

lets assume i have a hotpixel (bright purple). In the below "graph"
the hotpixel would be the "x" ... and all the other pixels are
depicted by "."

Here is my ( simplified ) example:

Lets assume i take a foto of a green background. all of the "."
would be green, except for the "x" which would be bright purple (in
my case)...

.....
.X..
.....

I do know the X/Y coordinates of the hot pixel (from one of the
hotpixel detection programs) ... wouldnt it be possible to write a
small photoshop macro to read the color values of the pixel around
the hotpixel and AUTOMATICALLY change the color of the hotpixel to
the color of the neighbour-pixels? (The idea is to move all photos
into a folder and have the macro change the color of the "X" to the
colour of the neighbour pixels AUTOMATICALLY).

I am aware that there are hotpixel programs, but the DO NOT KNOW
where the hotpixel is, thus have to "guess" by using smart
algorithms where a pixel is a hotpixel... but the truth is... WE
ALL KNOW WHERE OUR hotpixels are....

does this make sense? I agree it is a simplified example, but i
wanted to present the "BIG" idea, rather than discuss what happens
if every neighbour has a diferent color.

please feel encouraged to let any comments, i can´t write this
program, but i guess it would be a very simple routine, starting
with ingressing the coordinates of hot pixels, and leaving
unchanged 99.9999% of the other pixels ... or am i to optimistic?

thx for your time
alfred
Click to expand...
 
Yes, you can do that in Photoshop and it's not very difficult to record a proper macro for it. I've used a similiar technique on film/negative scanners that developed a dead pixel in their CCD. In that case, an entire line is screwed up through the image, as the negative/slide is panned over the CCD. The macro I created would take the line of pixels to the left & right of the 1 pixel defective line, and do a 50/50 transparency merge, leaving a perfect blend. It was completely undetectable once it was done no matter how much you looked for it or zoomed in.

I would batch scan the negatives/slides to a default folder, and then run an automated batch process in PS to fix the images. The process you are contemplating would be very similiar.
 
It is an interesting idea and I am inclined to build this into ABC-View Manager.

I think there's two stages to it:

1) The user points out the "general area" where a hot pixel is located. The algorithm searches for isolated color pixels and ask the user to confirm a found location. Then, it stores this hot-pixel location in a digicam profile for later use.

2) Later use: the user selects a batch of images, and tells to apply the hot-pixel elimination based on the stored profile. The algorithm will then blindly blend the surrounding pixels without even considering if they're the same color or perhaps a bit different.

The beautiful part is that this could even be done on JPG files, without loosing their quality by having to decompress and re-compress the complete image. Just one 8x8 pixel block would have to be altered.

Let me know if this is a sensible idea and if this would be a widespread problem. Do these hot pixels occur often? My camere hasn't got any.

Nils (Software Developer)
http://www.abc-view.com
Chad Wills said:
Yes, you can do that in Photoshop and it's not very difficult to
record a proper macro for it. I've used a similiar technique on
film/negative scanners that developed a dead pixel in their CCD.
In that case, an entire line is screwed up through the image, as
the negative/slide is panned over the CCD. The macro I created
would take the line of pixels to the left & right of the 1 pixel
defective line, and do a 50/50 transparency merge, leaving a
perfect blend. It was completely undetectable once it was done no
matter how much you looked for it or zoomed in.

I would batch scan the negatives/slides to a default folder, and
then run an automated batch process in PS to fix the images. The
process you are contemplating would be very similiar.
Click to expand...
 
Nils Haeck said:
Let me know if this is a sensible idea and if this would be a
widespread problem. Do these hot pixels occur often? My camere
hasn't got any.
Click to expand...
Yes, unfortunately it is my impression that they occur often: I've got three hotpixels in my Casio QV-3500.
Nils Haeck said:
Nils Haeck said:
I would batch scan the negatives/slides to a default folder, and
then run an automated batch process in PS to fix the images. The
process you are contemplating would be very similiar.
Click to expand...
Click to expand...
I have Photoshop 5.5, and I don't see how I can work on photos in batches, that is set it going with an action on a batch of photos and come back when it is finished. I always have to start the action for every single photo. Could you tell me how to do the batch-work, or does it only work for later versions of PS?

--- Freycinet http://www.iue.it/Personal/Researchers/Dalsgaard/
 
Nils,

hotpixels are common in DC ... and if you havent found any on your camera, you haven't looked hard enough ;o)

(just take a 4-8 sec exposure with the lens cap on)

they are common for 2 reasons:
  • higher Megapixel means more pixel to go bad
  • CCDs seem to age with time, developing HPixels
i finally found a VERY nice program, called "PixelZap" (search for it in http://www.google.com ) very good program, allows for automatic correction, black-shot correction or mapping coordinates.

its free to download, but the demo is limited to 640x480 (so you have to crop)... the full version is just 15 bucks, and well worth it...

again, thx for answering and I hope you find this information helpful

alfred
Nils Haeck said:
I think there's two stages to it:

1) The user points out the "general area" where a hot pixel is
located. The algorithm searches for isolated color pixels and ask
the user to confirm a found location. Then, it stores this
hot-pixel location in a digicam profile for later use.

2) Later use: the user selects a batch of images, and tells to
apply the hot-pixel elimination based on the stored profile. The
algorithm will then blindly blend the surrounding pixels without
even considering if they're the same color or perhaps a bit
different.

The beautiful part is that this could even be done on JPG files,
without loosing their quality by having to decompress and
re-compress the complete image. Just one 8x8 pixel block would have
to be altered.

Let me know if this is a sensible idea and if this would be a
widespread problem. Do these hot pixels occur often? My camere
hasn't got any.

Nils (Software Developer)
http://www.abc-view.com
Chad Wills said:
Yes, you can do that in Photoshop and it's not very difficult to
record a proper macro for it. I've used a similiar technique on
film/negative scanners that developed a dead pixel in their CCD.
In that case, an entire line is screwed up through the image, as
the negative/slide is panned over the CCD. The macro I created
would take the line of pixels to the left & right of the 1 pixel
defective line, and do a 50/50 transparency merge, leaving a
perfect blend. It was completely undetectable once it was done no
matter how much you looked for it or zoomed in.

I would batch scan the negatives/slides to a default folder, and
then run an automated batch process in PS to fix the images. The
process you are contemplating would be very similiar.
Click to expand...
Click to expand...
 
oops...

forgot to mention that the pixelZap supports batch-processes (just throw all your pics into a directory and they will all be processed and re-saved (lossless) with a distinction into the same directory)

i chose the distinction "FX", so a picture that was named "photo 1292.jpg" is now "photo 1292FX.jpg" - you can also chose where to put the distintion, so it could also be "FXphoto1292.jpg" -- thus being easier to sort...

also it addresses the "halo" issue around hotpixels

I can HIGHLY recommend this little program... the guy how wrote it, did know what he did

take
care
Alfred said:
hotpixels are common in DC ... and if you havent found any on your
camera, you haven't looked hard enough ;o)

(just take a 4-8 sec exposure with the lens cap on)

they are common for 2 reasons:
  • higher Megapixel means more pixel to go bad
  • CCDs seem to age with time, developing HPixels
i finally found a VERY nice program, called "PixelZap" (search for
it in http://www.google.com ) very good program, allows for automatic
correction, black-shot correction or mapping coordinates.

its free to download, but the demo is limited to 640x480 (so you
have to crop)... the full version is just 15 bucks, and well worth
it...

again, thx for answering and I hope you find this information helpful

alfred
Nils Haeck said:
I think there's two stages to it:

1) The user points out the "general area" where a hot pixel is
located. The algorithm searches for isolated color pixels and ask
the user to confirm a found location. Then, it stores this
hot-pixel location in a digicam profile for later use.

2) Later use: the user selects a batch of images, and tells to
apply the hot-pixel elimination based on the stored profile. The
algorithm will then blindly blend the surrounding pixels without
even considering if they're the same color or perhaps a bit
different.

The beautiful part is that this could even be done on JPG files,
without loosing their quality by having to decompress and
re-compress the complete image. Just one 8x8 pixel block would have
to be altered.

Let me know if this is a sensible idea and if this would be a
widespread problem. Do these hot pixels occur often? My camere
hasn't got any.

Nils (Software Developer)
http://www.abc-view.com
Chad Wills said:
Yes, you can do that in Photoshop and it's not very difficult to
record a proper macro for it. I've used a similiar technique on
film/negative scanners that developed a dead pixel in their CCD.
In that case, an entire line is screwed up through the image, as
the negative/slide is panned over the CCD. The macro I created
would take the line of pixels to the left & right of the 1 pixel
defective line, and do a 50/50 transparency merge, leaving a
perfect blend. It was completely undetectable once it was done no
matter how much you looked for it or zoomed in.

I would batch scan the negatives/slides to a default folder, and
then run an automated batch process in PS to fix the images. The
process you are contemplating would be very similiar.
Click to expand...
Click to expand...
Click to expand...
 
Freycinet said:
I have Photoshop 5.5, and I don't see how I can work on photos in
batches, that is set it going with an action on a batch of photos
and come back when it is finished. I always have to start the
action for every single photo. Could you tell me how to do the
batch-work, or does it only work for later versions of PS?
Click to expand...
I'm not sure if it's a version specific feature. I am using PS 6.01. On my program you would goto File-> Automate-> Batch. From there you choose your Source & Destination Folder, along with the macro you would like to play, and a few other options, like Include all subfolders, and override color settings. If your PS can't do it, it's worth the upgrade, also the color management and color proofing is setup much better in PS 6.
 
Alfred said:
I am not afiliated with the site or program, just one happy 990
owner with a real simple solution for a complicated problem
Click to expand...
It does sound a little suspect, though, that you write a post in which you lament that you have hotpixels and then just happen to have gotten a "crazy idea" about what could be done about it:

http://www.dpreview.com/forums/read.asp?forum=1004&message=2213365

And then the day after you plug a program on another post which does all you want, and more....

http://www.dpreview.com/forums/read.asp?forum=1004&message=2218375

I don't know, to me it sounds as if you are in some way affiliated.... - You write that you looked around for other programs but "none did REALLY work". In 24 hours you tried all the other programs and found none that really worked? - Furthermore, the tone in your post does have an unmistakable "advertisement"-feel to it... - It's quite different from the usual unbiased postings of ordinary users.

Anyway, I don't mind being informed about programs which can be useful, I just don't like it if it sounds to me as if the "objective" user information is not quite as "objective" as it pretends to be...--- Freycinet http://www.iue.it/Personal/Researchers/Dalsgaard/
 
You already have an operation that replaces pixel intensity values with those of a nearby values, the "median filter." Unfortunately, this applies to all pixels, not just hot pixels. The median filter should remove hot pixels at the expense of blurring the image. However, if you could generate and save a mask (or maybe "stencil" is a better term) that identifies the locations of the hot pixels, you could use it to transfer the pixel values from a median treated image to an untreated image at only the hot pixel locations. Since I do not use PS or other commercial software, I cannot tell you exactly how to do this, but I expect that there is an easy way to do this in PS.

I personally have no experience with hot pixels. If you post an example, I might be of better service to you.
Alfred said:
Hi there, i do have a problem with hot-pixels and i came up with a
nice idea... anybody care to comment if it would work or not????

here i go...

lets assume i have a hotpixel (bright purple). In the below "graph"
the hotpixel would be the "x" ... and all the other pixels are
depicted by "."

Here is my ( simplified ) example:

Lets assume i take a foto of a green background. all of the "."
would be green, except for the "x" which would be bright purple (in
my case)...

.....
.X..
.....

I do know the X/Y coordinates of the hot pixel (from one of the
hotpixel detection programs) ... wouldnt it be possible to write a
small photoshop macro to read the color values of the pixel around
the hotpixel and AUTOMATICALLY change the color of the hotpixel to
the color of the neighbour-pixels? (The idea is to move all photos
into a folder and have the macro change the color of the "X" to the
colour of the neighbour pixels AUTOMATICALLY).

I am aware that there are hotpixel programs, but the DO NOT KNOW
where the hotpixel is, thus have to "guess" by using smart
algorithms where a pixel is a hotpixel... but the truth is... WE
ALL KNOW WHERE OUR hotpixels are....

does this make sense? I agree it is a simplified example, but i
wanted to present the "BIG" idea, rather than discuss what happens
if every neighbour has a diferent color.

please feel encouraged to let any comments, i can´t write this
program, but i guess it would be a very simple routine, starting
with ingressing the coordinates of hot pixels, and leaving
unchanged 99.9999% of the other pixels ... or am i to optimistic?

thx for your time
alfred
Click to expand...
 
wrong guess...

i also posted the "crazy idea" post in the "pc tools" forum and there somebody pointed me to "Thumber", and from there i made my way to the pixelZap...(which seemes to be related in some way - as one guy commented)

the reason why i am so enthusiastic is that i recently bought a used 990 and it showed some 3 very bad hotpixels...:o(

as i do live in chile, Nikon chile just took 10 bucks for receiving the camera and telling me to change the ccd (US$ 400,-+)

thats when i started searchin the web (if you look, you will find other hotpixel mails of mine on the nikon board), downloading software (and none did really work :o) ....

the reason why i am so happy is that this program saved my the $$$ and aggrevation of changing the ccd and helped me overcome my "cognitive dissonances" after a $450,- used 990 deal on e-bay that seemed to backfire...

and about being afiliated... I just paid that guy (cant recall, but its an american name) 15 bucks for the full version ;oP

and funnily enough the "crazy idea" opened the door to someone telling me that this programs exists

I know that there are others out there with similar problems, and if you download the demo version, you can see for yourself if it works for you...

just trying to pass on the knowledge to others...

take care
Alfred Budschitz,
Stgo, Chile
Freycinet said:
Alfred said:
I am not afiliated with the site or program, just one happy 990
owner with a real simple solution for a complicated problem
Click to expand...
It does sound a little suspect, though, that you write a post in
which you lament that you have hotpixels and then just happen to
have gotten a "crazy idea" about what could be done about it:

http://www.dpreview.com/forums/read.asp?forum=1004&message=2213365

And then the day after you plug a program on another post which
does all you want, and more....

http://www.dpreview.com/forums/read.asp?forum=1004&message=2218375

I don't know, to me it sounds as if you are in some way
affiliated.... - You write that you looked around for other
programs but "none did REALLY work". In 24 hours you tried all the
other programs and found none that really worked? - Furthermore,
the tone in your post does have an unmistakable
"advertisement"-feel to it... - It's quite different from the usual
unbiased postings of ordinary users.

Anyway, I don't mind being informed about programs which can be
useful, I just don't like it if it sounds to me as if the
"objective" user information is not quite as "objective" as it
pretends to be...
--
  • Freycinet
http://www.iue.it/Personal/Researchers/Dalsgaard/
Click to expand...
 
hey, if you did take the time to research my postings-history,

why didnt you find those:
  • eliminating hot pixels Alfred
  • help!!! i got hot-pixels Alfred
  • how much for mapping out a hot-pixel on a ... Alfred
--- all of which are about 1-2 weeks old

... sometimes, the mind doesn't perceive what the eye sees, ... rather the eye sees what the mind wants to perceive....

... and please refrain from implying (explicitly or implicitly) that i am a dishonest person.

Alfred
Alfred said:
i also posted the "crazy idea" post in the "pc tools" forum and
there somebody pointed me to "Thumber", and from there i made my
way to the pixelZap...(which seemes to be related in some way - as
one guy commented)

the reason why i am so enthusiastic is that i recently bought a
used 990 and it showed some 3 very bad hotpixels...:o(

as i do live in chile, Nikon chile just took 10 bucks for receiving
the camera and telling me to change the ccd (US$ 400,-+)

thats when i started searchin the web (if you look, you will find
other hotpixel mails of mine on the nikon board), downloading
software (and none did really work :o) ....

the reason why i am so happy is that this program saved my the $$$
and aggrevation of changing the ccd and helped me overcome my
"cognitive dissonances" after a $450,- used 990 deal on e-bay that
seemed to backfire...

and about being afiliated... I just paid that guy (cant recall, but
its an american name) 15 bucks for the full version ;oP

and funnily enough the "crazy idea" opened the door to someone
telling me that this programs exists

I know that there are others out there with similar problems, and
if you download the demo version, you can see for yourself if it
works for you...

just trying to pass on the knowledge to others...

take care
Alfred Budschitz,
Stgo, Chile
Freycinet said:
Alfred said:
I am not afiliated with the site or program, just one happy 990
owner with a real simple solution for a complicated problem
Click to expand...
It does sound a little suspect, though, that you write a post in
which you lament that you have hotpixels and then just happen to
have gotten a "crazy idea" about what could be done about it:

http://www.dpreview.com/forums/read.asp?forum=1004&message=2213365

And then the day after you plug a program on another post which
does all you want, and more....

http://www.dpreview.com/forums/read.asp?forum=1004&message=2218375

I don't know, to me it sounds as if you are in some way
affiliated.... - You write that you looked around for other
programs but "none did REALLY work". In 24 hours you tried all the
other programs and found none that really worked? - Furthermore,
the tone in your post does have an unmistakable
"advertisement"-feel to it... - It's quite different from the usual
unbiased postings of ordinary users.

Anyway, I don't mind being informed about programs which can be
useful, I just don't like it if it sounds to me as if the
"objective" user information is not quite as "objective" as it
pretends to be...
--
  • Freycinet
http://www.iue.it/Personal/Researchers/Dalsgaard/
Click to expand...
Click to expand...
 
Chad Wills said:
cwills said:
I have Photoshop 5.5, and I don't see how I can work on photos in
batches, that is set it going with an action on a batch of photos
and come back when it is finished. I always have to start the
action for every single photo. Could you tell me how to do the
batch-work, or does it only work for later versions of PS?
Click to expand...
I'm not sure if it's a version specific feature. I am using PS
6.01. On my program you would goto File-> Automate-> Batch. From
there you choose your Source & Destination Folder, along with the
macro you would like to play, and a few other options, like Include
all subfolders, and override color settings. If your PS can't do
it, it's worth the upgrade, also the color management and color
proofing is setup much better in PS 6.
Click to expand...
I found it Chad, thanks a lot for the advice, it works like a charm, also on PS 5.5. - It's great!--- Freycinet http://www.iue.it/Personal/Researchers/Dalsgaard/
 
How in the world did you suffer so long having to do all your image processing by hand? I would have gone back to film, if not for the birthday present my wife gave me 3 years ago: Photoshop. Those actions are the ONLY reason I don't have a 1V instead of a D30. A friend, who just bought my G2, does not have Photoshop and the biggest obstacle to overcome is how he can batch process his images without it. Qimage seems to be the best 'batching' solution for him, unless someone else has a better way. I'd love to help him get a good start with his new digicam, but doing every pic manually is just out of the question for him. As is Photo$hop. Any suggestions?
Freycinet said:
I found it Chad, thanks a lot for the advice, it works like a
charm, also on PS 5.5. - It's great!
--
  • Freycinet
http://www.iue.it/Personal/Researchers/Dalsgaard/
Click to expand...
--Stay Focused http://home.attbi.com/~keylargographics
 
If he has more time than money, he can learn the wonders of the GIMP.

http://www.gimp.org

It's free, open source, and (I'm told) a worthy competitor of PhotoShop as far as capabilities.

It doesn't have a built-in batch mode, (at least in the Windows version) but it does have a command-line mode. I've not tried it myself, (still learning how to use the tool) but I'm sure there's a way to get it to do batch processing.

Good luck!--More people are caused by accidents than are killed by them.
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top