Digital Zoooooom!!! Another experiment!;-)

  • Thread starter Thread starter nahau
  • Start date Start date
Before finding which one is digital zoom, anyone notice the image in the inactive window inside Photoshop show more pixelation? Please note that the first one have active window on the left side while the second one have active window on the right side...

nahau, could you post another capture with active window on the right for the first one and active left window on the second?
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
Hi Whao,

Which window is "active" has nothing to do with pixelization. The active windows just so happened to be the last windows I resized to fit on my screen just before the capture was made. Unless...I am misunderstanding your concern here.
nahau
nahau, could you post another capture with active window on the
right for the first one and active left window on the second?
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
nahau,

I too am trained as an engineer. We like to make experiments with appropriate controls or "counterfactuals." When some says that the digital zoom is worthless they are not saying compared to what. A digital zoom picture is not as good as the same picture with the optical zoom, say if someone were able to step closer and get the same picture. So, one would always composes a picture if possible to the extent of the optical zoom, in my opinion. When you get out to the full extent of the optical zoom and still want more magnification, you either walk closer, take it and crop in the computer(and maybe increase file size with PS-Image Size, for example), or use the digital zoom. Something you and Tom haven't talked about is file size for printing. He may be correct that you get to the same picture and file size whether you have the camera digitally zoom in with its model or have PS crop it and then enlarge with its model, holding everything else constant. Or, are you not digitally zooming but cropping in PS and getting a smaller file size to print with? If you can get a picture by not using the digital zoom and cropping and have a file resolution large enough to produce a good print, say > 240 ppi (or should this be dpi?), then that is probably the best strategy. If you have to use image size to enlarge the picture in PS to get a file size you want, then you are back to which has the better model--in camera G1 or PS? My experience from my comparisons that if shot on a tripod, they are about the same.

Bill
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
Tome,

Taking your two assuptions, yes, there should be no difference. However, you have to make a third assumption; the shutter speed must be fast enough to negate any impact of hand shaking in view of the longer zooming. If you have the experience of pushing the digital zoom of a camcorder to the extreme (say 120x), you know what I mean. Your hand shake so much that it is difficult to aim at the target.

So even with your two assumptions, I still believe that unless you use a tripod (and the remote control if it is available), it is better to push to the optical zoom limit and then do the digital zooming in the computer.

Is digital zooming of a digicam a useless feature? I think sometimes it is useful. There are always people who do not want to use the computer to edit pictures. They just want to record down what they see on the LCD of the camera. They feel more comfortable (and reassuring) that way. There is nothing wrong with this. Photography has different meanings to different people.

Regards,

K. Tse
I have to chuckle why folks seem to think digital zoom should look
worse.
Ignoring any...
1) differences in the enlargement "technique" used by the camera
vs. external software
2) distortions created by additional or differing quality jpeg
compression

there should be absolutely NO difference in quality between the two
pictures, or am I missing something?
 
Hi Bill,

As a matter of fact, the first digital zoom scenario discussed with Nadim was based on optical vs digital zoom. As it turned out, and as expected, optical will always win out. Data is data and the more you have to work with in the beginning, the more resolution is available for use during processing...whether on the computer or during printing. Interpolation or transformation done by computer can simulate missing data and even add more data to a file, however, resolution cannot be raised to a level higher than what you started with without highly sophisticated software routines...or pixel by pixel realignments. This is of course the premise behind Genuine Fractals and it's usage. Even then, GF is still limited. If ever someone invents a program that can in fact "create" resolution... we will no longer have need for larger ccd sizes! Wouldn't that be something?

Of course for everyday use, digital zoom vs computer enlargement may not have any affect on printing either way...unless you print to a size that can show the difference. Most people do print, but I would think displaying on the screen heavily outweighs what is printed.

On the other hand though.....if you look at the photos that includes the label... which of the two sides do you think the label would be legible in...say if you printed at 8 x 10...or even at 5 x 7? Something to consider. By the way...what is your guess?;-)
nahau
I too am trained as an engineer. We like to make experiments with
appropriate controls or "counterfactuals." When some says that the
digital zoom is worthless they are not saying compared to what. A
digital zoom picture is not as good as the same picture with the
optical zoom, say if someone were able to step closer and get the
same picture. So, one would always composes a picture if possible
to the extent of the optical zoom, in my opinion. When you get out
to the full extent of the optical zoom and still want more
magnification, you either walk closer, take it and crop in the
computer(and maybe increase file size with PS-Image Size, for
example), or use the digital zoom. Something you and Tom haven't
talked about is file size for printing. He may be correct that you
get to the same picture and file size whether you have the camera
digitally zoom in with its model or have PS crop it and then
enlarge with its model, holding everything else constant. Or, are
you not digitally zooming but cropping in PS and getting a smaller
file size to print with? If you can get a picture by not using the
digital zoom and cropping and have a file resolution large enough
to produce a good print, say > 240 ppi (or should this be dpi?),
then that is probably the best strategy. If you have to use image
size to enlarge the picture in PS to get a file size you want, then
you are back to which has the better model--in camera G1 or PS? My
experience from my comparisons that if shot on a tripod, they are
about the same.

Bill
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
When I first read this topic, I was sure about it: Picture 1 right and picture 2 left were the digital-zoomed pictures.

I put it to the test with my Canon Pro 90 IS.
Took a picture (using tripod).
Took a second picture with 4x zoom
Cropped the first picture to 1/4 of the original size.
Then I went resizing with Paintshop Pro 7

I resized the cropped picture to 400% (same size as the 4x digital zoomed picture). I used 4 different ways of resizing:
Pixel resize: as you would expect: this sucks
Biliniair resize: better... but not as good as the 4x digital zoomed picture

Bicubic resize: again better... but still nog as good as the 4x digital zoomed picture

Smart resize: better than bicubic, better than biliniair and better than pixel resize.... but not as good as the 4x digital zoomed...

So I have to say... I drop my first guess and think the left first picture and the right second picture are the digital zoomed...
Conclusion... the camera does a better job with digital zoom.....

I'm eager to hear the real thing about the pictures
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
So I have to say... I drop my first guess and think the left first
picture and the right second picture are the digital zoomed...
Conclusion... the camera does a better job with digital zoom.....
I agree... this reflects my experiences with several digital cameras and their digital zoom... loss of resolution is there, but pretty well minimized by the camera's internal processing algorithms.
 
So I have to say... I drop my first guess and think the left first
picture and the right second picture are the digital zoomed...
Conclusion... the camera does a better job with digital zoom.....
I agree... this reflects my experiences with several digital
cameras and their digital zoom... loss of resolution is there, but
pretty well minimized by the camera's internal processing
algorithms.
Weird... I just did the same test, only with another picture and 2x zoom.

Now the cropped-resized picture looks better.
The 2x digital zoomed picture looks a bit blurry/unsharp

The 2x digital zoom picture:



The 1x digital zoom, cropped, 200% picture:



Looking at these pictures, I have to go to my first guess.... first picture: right picture is digital zoom
second picture: left picture is digital zoom

I could be wrong... but compared to my second test (with 2x digital zoom), this has to be the answer.
 
Hi Nahau,

I'm shure that the pics with the better anti-aliasing (the less pixelated pics) are straight from the G1.

There are two reason for this statement:

First I got a G1 and Photoshop 5 LE too :-)

Second I made many experiments with zooming pics by software, before I got my first digicam. I tested many photo editors and found out, that - beleave it or not - the best software for zooming with an excellent anti-aliasing is ... Corel Photo Paint ... no joke.

Greetings from Germany

Chris
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
Hi Nahau, one of the problems with written forums is it is hard to get a feel for the color or someone's comments. All we really have are woefully inadequate smiley faces, abbreviations, capital letters, etc. I did not mean to insult (or trade insults with anyone), hence the smiley face after what could have be interpreted as an insult, so apologies if you or anyone read it that way.

All I was trying to point out was that it seems what you are doing is comparing processing algorithtms between the camera and photoshop (or some other) software. My concern is that some of the less informed folks might come away thinking digital zoom is "superior". I'm not an engineer, but logic tells me one cannot conclude the camera's digital zoom (internal processing) will necessarily do a better job than external processing (all potential algorithms considered). For example, if the external processing is done from a RAW file and uses EXACTLY the same algorithm(s) as in camera I would argue the two results MUST be identical.

Also, I don't understand all the camera shake arguments. If the argument is that that digital zoom will change aprerature settings, etc, then yes I agree that digital zoom could potentially produce superior results, but then I don't think we are talking about an "apples to apples" comparison.

Again, please don't take these comments the wrong way. I am just trying to better understand the rationale and logic behind the various arguments being made.

When a magician saws someone in half, I can't deny what I see, but logic tells me something else is going on behind the scenes to better explain it...Tom
 
nahau,

I believe the top left is a better image and can see almost no difference in th bottom images. I forget or you did not specify how you computer enlarged, but I will guess the computer enlargement is top left and bottom right.

Bill
I too am trained as an engineer. We like to make experiments with
appropriate controls or "counterfactuals." When some says that the
digital zoom is worthless they are not saying compared to what. A
digital zoom picture is not as good as the same picture with the
optical zoom, say if someone were able to step closer and get the
same picture. So, one would always composes a picture if possible
to the extent of the optical zoom, in my opinion. When you get out
to the full extent of the optical zoom and still want more
magnification, you either walk closer, take it and crop in the
computer(and maybe increase file size with PS-Image Size, for
example), or use the digital zoom. Something you and Tom haven't
talked about is file size for printing. He may be correct that you
get to the same picture and file size whether you have the camera
digitally zoom in with its model or have PS crop it and then
enlarge with its model, holding everything else constant. Or, are
you not digitally zooming but cropping in PS and getting a smaller
file size to print with? If you can get a picture by not using the
digital zoom and cropping and have a file resolution large enough
to produce a good print, say > 240 ppi (or should this be dpi?),
then that is probably the best strategy. If you have to use image
size to enlarge the picture in PS to get a file size you want, then
you are back to which has the better model--in camera G1 or PS? My
experience from my comparisons that if shot on a tripod, they are
about the same.

Bill
A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
Basically, I don't think folks have enough information to make an
educated choice. For example, is Nahau's digitally enlarged imaged
done straight from a RAW image file? If so, there is not an extra
jpg compression. But then comparison is not apples vs. apples due
to essentailly comparing RAW vs. jpg output from the camera...Tom
At his zoom level, the RAW vs jpeg differences would be very limited. At low compression levels, jpeg files might show a little noise at corners or along edges of high contrast, but not the overall blockiness seen in the worse two of his images. The blockiness is clearly the result of less information than the other image.

Why is everyone ignoring the obvious answer - the camera contains more information than is stored even in a RAW image, and is using that to its benefit when digital zooming a picture. A reasonably well done digital zooms will always be better than even the best zoom on a computer because the camera has more information to work with.
 
Hi Tom,

I agree 100% with the fact that written misunderstandings can get out of hand. However, sometimes friends need to fight before mutual respect can be gained!;-) I think we have reached that point...at least I have.

I am really not attempting to sway anyone here. I would think that all involved would be able to make their own judgement calls on how they approach photography.

Digital zoom has recieved a bad name in the form of video cameras and now digicams. Phil probably wrote that digital zoom piece long before he even tested the newer cameras with better and improved internal processing algos. Even I, for the longest time, had a stigma about referencing digital zoom as a viable tool. To this day, back in my mind, the stigma still exists. I think people must begin to open their mind to different possibilities, especially since newer and smarter technologies are now employed that were not available just a few years ago.

I have to disagree with you somewhat on your logic in thinking that there is no way for the camera to accomplish better processing than the computer. Without actually knowing the exact camera process (algos), you have no "measure" except what is shown on your computer in whatever application you use to process your photos. Once you download the files, the camera is out of it. It no longer matters what the camera did to the photos because the files are now just stand alone files resident on the computer. It's like this...if I were to email you a couple of pictures and told you they were exactly alike, and then you saw a difference between the two photos, would you then think anything about which camera and what type of processing the camera did to cause the difference in the photos? I don't know if you follow along with that, but what I am trying to say here is that files downloaded from the camera must now be treated as single entities with no ties to any camera. An application must now process it, and however that application processes one, it will do the same for all...unless of course you change the process of the application itself.

I do agree with what you say about if the camera algos are the same as application algos, there should be no difference in the images. The downside (or upside, depending on where you stand) is that it appears the camera vs applications are different, and so the question is...which is better? My answer is, "it depends". These photos were shot with "my" G1. Photos shot with other G1s, nikons, sonys, fujis, other canons, etc, may not do as well with internal interpolation of digital zooming. How other cameras fare is left up to the individual owners to decide on their own...through testing. For me, I have found that digital zooming is superior to computer enlargements. The files are less noisy, with less "visible" artifacts...as this experiment has shown.

As I said before, I am an engineer, and early on in my career, I learned one thing....what works in theory, doesn't necessarily work in the real world...and logic can be fooled.
nahau
Hi Nahau, one of the problems with written forums is it is hard to
get a feel for the color or someone's comments. All we really have
are woefully inadequate smiley faces, abbreviations, capital
letters, etc. I did not mean to insult (or trade insults with
anyone), hence the smiley face after what could have be interpreted
as an insult, so apologies if you or anyone read it that way.

All I was trying to point out was that it seems what you are doing
is comparing processing algorithtms between the camera and
photoshop (or some other) software. My concern is that some of the
less informed folks might come away thinking digital zoom is
"superior". I'm not an engineer, but logic tells me one cannot
conclude the camera's digital zoom (internal processing) will
necessarily do a better job than external processing (all potential
algorithms considered). For example, if the external processing is
done from a RAW file and uses EXACTLY the same algorithm(s) as in
camera I would argue the two results MUST be identical.

Also, I don't understand all the camera shake arguments. If the
argument is that that digital zoom will change aprerature settings,
etc, then yes I agree that digital zoom could potentially produce
superior results, but then I don't think we are talking about an
"apples to apples" comparison.

Again, please don't take these comments the wrong way. I am just
trying to better understand the rationale and logic behind the
various arguments being made.

When a magician saws someone in half, I can't deny what I see, but
logic tells me something else is going on behind the scenes to
better explain it...Tom
 
As mentioned in my early response to this thread, so far I only once used the digital zoom on the G1 seriously and saved the result. My guess (digizoom: 1. left, 2. right) was based on this experience of mine. Here are my examples: One was shot by using 4x digital zoom. Another is an 4x enlargement with Photoshop. They were not taken on the same day. But one can tell certain properties of the two methods, anyway. Their real identities can be found in my sample album:



Nahau, you must be very busy in "looking after" your hot thread today. Now, I even cannot catch if you've published your results "officially", although you almost revealed them in your last response. Please announce it on the subject line. Thanks!
Yang




A while back, I did an experiment with digital zoom. The main
discussion involved myself and Nadim. A lot of you don't know
Nadim, but he is very knowledgable in the use of Photoshop, Genuine
fractals, etc. In any case I thought it would be interesting to
see just how many people think of digital zoom as a "marketing
ploy" with no added value.
Below are two captures split left and right. I won't say which is
the digitally zoomed image and which is computer enlarged...it
would be more fun to see how many people can guess which is
which...correctly!;-)
I purposely did not put the digitally zoomed photos on any
specified side of the either capture...which means, that the
digitally zoomed photos could either be on the left side or the
right side. Hmmmm...which ones are they??





Any Guesses???
nahau
 
Sorry, I put a wrong like for my album by mistake. The correct one is:
http://www.fototime.com/inv/8F6E138FE25B2AB
Yang
As mentioned in my early response to this thread, so far I only
once used the digital zoom on the G1 seriously and saved the
result. My guess (digizoom: 1. left, 2. right) was based on this
experience of mine. Here are my examples: One was shot by using 4x
digital zoom. Another is an 4x enlargement with Photoshop. They
were not taken on the same day. But one can tell certain properties
of the two methods, anyway. Their real identities can be found in
my sample album:
...
 
Spejic, are you sure about this? Maybe I don't understand RAW then. I thought RAW was basically what the camera sees, i.e. the "raw" image from the cam. In any case, I wouldn't go so far as to say digital zoom will "always" be better. I gotta think the best digital zoom algorithm(s) have yet to be discovered / invented, so I personally will shoot with RAW and roll the dice that external software will do as good of a job of digital zooming, if not today, then in the future. Also, as Nahau has highlighted with the magenta issue, shooting in RAW is really the only way to go when quality is of critical importance...Tom
Why is everyone ignoring the obvious answer - the camera contains
more information than is stored even in a RAW image, and is using
that to its benefit when digital zooming a picture. A reasonably
well done digital zooms will always be better than even the best
zoom on a computer because the camera has more information to work
with.
 
Tom,

After thinking about the hand shaking problem for a while, I am withdraw my argument now.

The digital zoom does not change the optical zoom which has already been put to its limit. The digital amplification of the view in the LCD "fools" us to think that the camera shaking has become more serious.

I agree that if the zooming algorithm is the same in the camera and the computer and if the pictures to be compared were taken under the same conditions, the zooming result should be the same.

I think in order to perform a fair comparison, we have to put as many variables under control as possible so that we are, as what you said, comparing "apples" with "apples".

This means that we have to use the same file format (RAW, JPEG), same resolution, same compression ratio if using JPG, the same shutter speed and aperture, the same white-balance, using a tripod to eliminate any possible camera shaking difference and if possible the same light condition. Basically shoot in M mode within a controlled enviroment (e.g. a still object indoor with controlled light condition).

There is still one problem: we do not know what is happening inside a digicam when it performs digital zooming. Would it just do the "zooming" or would it do something extra, e.g. increase the sharpening, contrast, ...etc. without telling us.

Regards,

K. Tse
Hi Nahau, one of the problems with written forums is it is hard to
get a feel for the color or someone's comments. All we really have
are woefully inadequate smiley faces, abbreviations, capital
letters, etc. I did not mean to insult (or trade insults with
anyone), hence the smiley face after what could have be interpreted
as an insult, so apologies if you or anyone read it that way.

All I was trying to point out was that it seems what you are doing
is comparing processing algorithtms between the camera and
photoshop (or some other) software. My concern is that some of the
less informed folks might come away thinking digital zoom is
"superior". I'm not an engineer, but logic tells me one cannot
conclude the camera's digital zoom (internal processing) will
necessarily do a better job than external processing (all potential
algorithms considered). For example, if the external processing is
done from a RAW file and uses EXACTLY the same algorithm(s) as in
camera I would argue the two results MUST be identical.

Also, I don't understand all the camera shake arguments. If the
argument is that that digital zoom will change aprerature settings,
etc, then yes I agree that digital zoom could potentially produce
superior results, but then I don't think we are talking about an
"apples to apples" comparison.

Again, please don't take these comments the wrong way. I am just
trying to better understand the rationale and logic behind the
various arguments being made.

When a magician saws someone in half, I can't deny what I see, but
logic tells me something else is going on behind the scenes to
better explain it...Tom
 
Hi all,
I guess it's time to let you know which is which.

In the first photo, the left side is digitally zoomed. The right is enlarged.

In the second photo, the right side is digitally zoomed, the left is enlarged.

Whether or not you would choose to use digital zoom, is totally up to you. My experience is that I have had better luck using the camera for zooming digitally than using software to enlarge a scene. In combination with the B300 and 2X digital, the G1 becomes a 10X camera. A very fine combination than just 6x without the digital zooming.

Thank you all for participating, it was fun to find out what many thought about the subject!
nahau
 

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