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Science Forum Index » Image Processing Forum » Shrinking a picture --- and it becomes blur !!
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| Guest |
 Posted: Mon Apr 28, 2008 8:39 pm |
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Hello !
I do computer graphics as a hobby, and have produced quite a number of
stunning graphics. Often time though, when I shrink the graphic to put
them online, they become blurred !!
I do all kinds of computer graphics, from fractals to virtual
landscape, to sci-fi rendering, using softwares ranging from photoshop
to terragen to povray.
When I am satisfied with a certain creation, I often make a master
copy with the resolution of 8192 X 6144 pixel. Why that size? Because
that's the largest size my puny computer (dual-core 3GHz CPU running
XP with 4GB RAM) can produce within a reasonably timeframe. (Give or
take 8 hours for rendering).
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
However, I found that when I do that, many interesting minute details
that were in the 8K X 6K pictures (even when I shrink fit it to my
1024X768 desktop as wallpaper) are GONE. In the 1024 X 768 JPG files,
all those details become blurred. No matter it's a JPG ---> JPG
shrink, or BMP ---> JPG shrink, or TIFF ---> JPG shrink, all those
details are GONE !!
I have experimented with many different graphic / photo softwares in
the shrinking process, all of them give me the same "blurring" effect.
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
Sincerely,
Lee |
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| Guest |
| Posted: Mon Apr 28, 2008 10:42 pm |
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On Apr 29, 4:39 pm, hsyq...@gmail.com wrote:
Quote: Hello !
I do computer graphics as a hobby, and have produced quite a number of
stunning graphics. Often time though, when I shrink the graphic to put
them online, they become blurred !!
I do all kinds of computer graphics, from fractals to virtual
landscape, to sci-fi rendering, using softwares ranging from photoshop
to terragen to povray.
When I am satisfied with a certain creation, I often make a master
copy with the resolution of 8192 X 6144 pixel. Why that size? Because
that's the largest size my puny computer (dual-core 3GHz CPU running
XP with 4GB RAM) can produce within a reasonably timeframe. (Give or
take 8 hours for rendering).
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
However, I found that when I do that, many interesting minute details
that were in the 8K X 6K pictures (even when I shrink fit it to my
1024X768 desktop as wallpaper) are GONE. In the 1024 X 768 JPG files,
all those details become blurred. No matter it's a JPG ---> JPG
shrink, or BMP ---> JPG shrink, or TIFF ---> JPG shrink, all those
details are GONE !!
I have experimented with many different graphic / photo softwares in
the shrinking process, all of them give me the same "blurring" effect.
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
Sincerely,
Lee
As advised, rendering to the size you want may be the best way.
Or try the "Lanczos" algorithm - eg in Irfanview. Also, downsizing in
steps may work better, in other words, try reducing in steps of say
20% (or even less), and then experiment with light sharpening (USM) at
each step - Irfanview has this function built in, but I can usually do
a little better manually. I've found what works for some images,
doesn't work as well for others.. and I've never experimented with
rendered images, so all this may be useless... (O:
The best you can hope for is one/two-pixel sharpness, so maybe you are
expecting too much? |
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| Guest |
| Posted: Tue Apr 29, 2008 12:33 am |
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On Apr 28, 11:39 pm, hsyq...@gmail.com wrote:
Quote: Hello !
I do computer graphics as a hobby, and have produced quite a number of
stunning graphics. Often time though, when I shrink the graphic to put
them online, they become blurred !!
I do all kinds of computer graphics, from fractals to virtual
landscape, to sci-fi rendering, using softwares ranging from photoshop
to terragen to povray.
When I am satisfied with a certain creation, I often make a master
copy with the resolution of 8192 X 6144 pixel. Why that size? Because
that's the largest size my puny computer (dual-core 3GHz CPU running
XP with 4GB RAM) can produce within a reasonably timeframe. (Give or
take 8 hours for rendering).
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
However, I found that when I do that, many interesting minute details
that were in the 8K X 6K pictures (even when I shrink fit it to my
1024X768 desktop as wallpaper) are GONE. In the 1024 X 768 JPG files,
all those details become blurred. No matter it's a JPG ---> JPG
shrink, or BMP ---> JPG shrink, or TIFF ---> JPG shrink, all those
details are GONE !!
I have experimented with many different graphic / photo softwares in
the shrinking process, all of them give me the same "blurring" effect.
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
Sincerely,
Lee
Interesting problem you got there. Perhaps you could speed up the
rendering time by getting some fancy video card that is powered by
super-duper ultra fast GPU ??
Which GPU the best? Hmmm......... |
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| Guest |
| Posted: Tue Apr 29, 2008 12:42 am |
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On Apr 29, 8:13 pm, bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
Quote: mark.thoma...@gmail.com wrote:
On Apr 29, 4:39 pm, hsyq...@gmail.com wrote:
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
As advised, rendering to the size you want may be the best way.
Or try the "Lanczos" algorithm
Since the downsize is an exact integer (factor of 
I'm not sure Lanczos (or anything "better" than bilinear)
would help.
BugBear
But I did also refer to downsizing in much smaller steps - and Lanczos
will possibly help there... |
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| N |
| Posted: Tue Apr 29, 2008 1:57 am |
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Guest
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<hsyq8xg@gmail.com> wrote in message
news:52088436-f3ae-42a8-862f-cb283c8c517c@q24g2000prf.googlegroups.com...
Quote: Hello !
I do computer graphics as a hobby, and have produced quite a number of
stunning graphics. Often time though, when I shrink the graphic to put
them online, they become blurred !!
I do all kinds of computer graphics, from fractals to virtual
landscape, to sci-fi rendering, using softwares ranging from photoshop
to terragen to povray.
When I am satisfied with a certain creation, I often make a master
copy with the resolution of 8192 X 6144 pixel. Why that size? Because
that's the largest size my puny computer (dual-core 3GHz CPU running
XP with 4GB RAM) can produce within a reasonably timeframe. (Give or
take 8 hours for rendering).
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
However, I found that when I do that, many interesting minute details
that were in the 8K X 6K pictures (even when I shrink fit it to my
1024X768 desktop as wallpaper) are GONE. In the 1024 X 768 JPG files,
all those details become blurred. No matter it's a JPG ---> JPG
shrink, or BMP ---> JPG shrink, or TIFF ---> JPG shrink, all those
details are GONE !!
I have experimented with many different graphic / photo softwares in
the shrinking process, all of them give me the same "blurring" effect.
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
Sincerely,
Lee
What were expecting? If you remove seven eighths of the data then seven
eighths of the data will be gone. |
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| Andrew Morton |
| Posted: Tue Apr 29, 2008 3:25 am |
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Guest
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hsyq8xg@gmail.com wrote:
Quote: When I am satisfied with a certain creation, I often make a master
copy with the resolution of 8192 X 6144 pixel. Why that size? Because
that's the largest size my puny computer (dual-core 3GHz CPU running
XP with 4GB RAM) can produce within a reasonably timeframe. (Give or
take 8 hours for rendering).
You should render it to the size you're going to use. And then it'll only
take a few minutes to render. You can always render it to a different size
if needed.
<snip: saves as jpeg>
Quote: However, I found that when I do that, many interesting minute details
that were in the 8K X 6K pictures (even when I shrink fit it to my
1024X768 desktop as wallpaper) are GONE.
That's what jpeg compression does. It is a lossy compression method.
How about saving as a png? It may not produce files as small as jpeg, but
the images will not be blurred (assuming you don't use jpeg compression in
the png!).
Andrew |
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| bugbear |
| Posted: Tue Apr 29, 2008 5:13 am |
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Guest
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mark.thomas.7@gmail.com wrote:
Quote: On Apr 29, 4:39 pm, hsyq...@gmail.com wrote:
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
As advised, rendering to the size you want may be the best way.
Or try the "Lanczos" algorithm
Since the downsize is an exact integer (factor of
I'm not sure Lanczos (or anything "better" than bilinear)
would help.
BugBear |
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| k |
| Posted: Tue Apr 29, 2008 5:38 am |
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Guest
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| Allen |
| Posted: Tue Apr 29, 2008 9:04 am |
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Guest
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k wrote:
machine, taking up memory and cycles and competing with your graphics
program? If you don't know, press CTRL-ALT-DEL to bring up Windows Task
Manager and click on Applications, the Processes, then Performance. You
might be forcing your graphics program to plod through knee-deep mud to
do its job.
Allen |
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| Duddits |
| Posted: Tue Apr 29, 2008 9:04 am |
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Guest
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On Mon, 28 Apr 2008 23:39:48 -0700 (PDT), hsyq8xg@gmail.com wrote:
Quote: snip
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
IrfanView gives you a choice of 5 filters when resizing. Try each of these
until you get the desired results.
http://www.irfanview.com
regards
Dud |
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| Sagiv |
| Posted: Tue Apr 29, 2008 9:43 am |
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Guest
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I assume the software you’re using performs antialiasing (a low-pass
filter) when
shrinking an image which has a blurring effect. In order to check this
out, you can create a synthetic bar image (half black half white) and
try to resize it. If the edge gets blurred – it’s most probably due to
the antialiasing filter.
I don’t know whether you can ask the software not to perform this
filter in advanced, but you can always code it yourself (using MATLAB/
C etc.).
-Sagiv. |
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| Martin Brown |
| Posted: Tue Apr 29, 2008 11:04 am |
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Guest
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Duddits wrote:
Quote: On Mon, 28 Apr 2008 23:39:48 -0700 (PDT), hsyq8xg@gmail.com wrote:
snip
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
Render the image to the size you want it in the first place. Then choose
your JPEG compression parameters and chroma subsampling carefully and
wisely to get the best size vs quality tradeoff. Several packages allow
you to see the size and preview artefacts against the original.
Before any meaningful answer about downsampling is possible you are
going to have to answer the question "what do I mean by an interesting
detail".
Quote:
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
IrfanView gives you a choice of 5 filters when resizing. Try each of these
until you get the desired results.
http://www.irfanview.com
Downsampling by a factor of 8 in each linear dimension will necessarily
have a pretty severe effect on the maximum spatial frequency of the
original image that can be retained. There is no free lunch.
Regards,
Martin Brown
** Posted from http://www.teranews.com ** |
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| aruzinsky |
| Posted: Tue Apr 29, 2008 11:13 am |
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Guest
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On Apr 29, 12:39 am, hsyq...@gmail.com wrote:
Quote: Hello !
I do computer graphics as a hobby, and have produced quite a number of
stunning graphics. Often time though, when I shrink the graphic to put
them online, they become blurred !!
I do all kinds of computer graphics, from fractals to virtual
landscape, to sci-fi rendering, using softwares ranging from photoshop
to terragen to povray.
When I am satisfied with a certain creation, I often make a master
copy with the resolution of 8192 X 6144 pixel. Why that size? Because
that's the largest size my puny computer (dual-core 3GHz CPU running
XP with 4GB RAM) can produce within a reasonably timeframe. (Give or
take 8 hours for rendering).
As the filesize for a JPG with 8192 X 6144 resolution may go up to 30+
MB, I often have to shrink them to a more reasonable 1024 X 768,
filesize about 800 KB or so.
However, I found that when I do that, many interesting minute details
that were in the 8K X 6K pictures (even when I shrink fit it to my
1024X768 desktop as wallpaper) are GONE. In the 1024 X 768 JPG files,
all those details become blurred. No matter it's a JPG ---> JPG
shrink, or BMP ---> JPG shrink, or TIFF ---> JPG shrink, all those
details are GONE !!
I have experimented with many different graphic / photo softwares in
the shrinking process, all of them give me the same "blurring" effect.
Now my questions to all you Gurus as below ---
1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?
2. Which software do you recommend to carry out the shrinking
operation?
Thank you all in advance !!!
Sincerely,
Lee
Instead of excess verbosity, you should post links to crops of before
and after images showing the problem areas.
You (plural) are not entitled to ignore the adage, "A picture is worth
a thousand words." |
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| Marco Tedaldi |
| Posted: Tue Apr 29, 2008 1:32 pm |
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Guest
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mark.thomas.7@gmail.com wrote:
Quote:
As advised, rendering to the size you want may be the best way.
That's the best approach...
Quote: Or try the "Lanczos" algorithm - eg in Irfanview. Also, downsizing in
steps may work better, in other words, try reducing in steps of say
20% (or even less), and then experiment with light sharpening (USM) at
each step - Irfanview has this function built in, but I can usually do
a little better manually. I've found what works for some images,
doesn't work as well for others.. and I've never experimented with
rendered images, so all this may be useless... (O:
Can you explain, why there should be any advantage in scaling down an
image in smaller steps? I've read this several times by now and can just
say that this seems like some quite big bullshit to me.
Maybe you can prove me wrong by supplying three images:
- original
- downsized in one step
- downsized in several steps
and the exact steps you used to get this result.
The logic behind downsizing in several stps is not clear to me. you
downsize by 20%... so you lose some information and the computer has to
interpolate ("guess" some values). After this you use this guessed
values to further shrink the image... and this should lead to better
results (and more detail) than downsizing in one step?
If this was true, I'd fire ALL (every single one) developer of the
scaling-procedures in every graphics program!
And think a bit further: IF there was an advantage in scaling down in
steps, the would be such a function built in the graphics-applications.
Ok, you can prove me wrong. Good luck! Mathematics and
Information-Theory is normally hard to beat!
Quote: The best you can hope for is one/two-pixel sharpness, so maybe you are
expecting too much?
That's for sure. Maybe he would be happiest with the cheapest
scaling-procedure available. No interpolation at all (i.e. nearest
neighbor). This will give him the sharpest image possible.
Marco
--
Dimage A2, Agfa isolette
http://flickr.com/photos/kruemi
http://profile.imageshack.us/user/kruemi/images |
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| Marco Tedaldi |
| Posted: Tue Apr 29, 2008 1:33 pm |
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Guest
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mark.thomas.7@gmail.com wrote:
Quote:
As advised, rendering to the size you want may be the best way.
That's the best approach...
Quote: Or try the "Lanczos" algorithm - eg in Irfanview. Also, downsizing in
steps may work better, in other words, try reducing in steps of say
20% (or even less), and then experiment with light sharpening (USM) at
each step - Irfanview has this function built in, but I can usually do
a little better manually. I've found what works for some images,
doesn't work as well for others.. and I've never experimented with
rendered images, so all this may be useless... (O:
Can you explain, why there should be any advantage in scaling down an
image in smaller steps? I've read this several times by now and can just
say that this seems like some quite big bullshit to me.
Maybe you can prove me wrong by supplying three images:
- original
- downsized in one step
- downsized in several steps
and the exact steps you used to get this result.
The logic behind downsizing in several stps is not clear to me. you
downsize by 20%... so you lose some information and the computer has to
interpolate ("guess" some values). After this you use this guessed
values to further shrink the image... and this should lead to better
results (and more detail) than downsizing in one step?
If this was true, I'd fire ALL (every single one) developer of the
scaling-procedures in every graphics program!
And think a bit further: IF there was an advantage in scaling down in
steps, the would be such a function built in the graphics-applications.
Ok, you can prove me wrong. Good luck! Mathematics and
Information-Theory is normally hard to beat!
Quote: The best you can hope for is one/two-pixel sharpness, so maybe you are
expecting too much?
That's for sure. Maybe he would be happiest with the cheapest
scaling-procedure available. No interpolation at all (i.e. nearest
neighbor). This will give him the sharpest image possible.
Marco
--
Dimage A2, Agfa isolette
http://flickr.com/photos/kruemi
http://profile.imageshack.us/user/kruemi/images |
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