Since the downsize is an exact integer (factor of
I'm not sure Lanczos (or anything "better" than bilinear)
would help.

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

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.

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 !!

In article
52088436-f3ae-42a8-862f-cb283c8c517c@q24g2000prf.googlegroups.com>,
hsyq8xg@gmail.com wrote:

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 !!

Well, of course! What did you expect?

If you resize an image to make it smaller, you remove pixels. When you
remove pixels, you remove detail.

On top of that, if you save as JPEG, you remove even more detail. JPEG
compression is "lossy." It was invented for situations where file size
is critical and image quality is not important. It makes files smaller
by discarding image detail.

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.

On Apr 29, 8:13?pm, bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
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...

Instead of excess verbosity, you should post links to crops of before
and after images showing the problem areas.

As for it being an exact integer ratio, that doesn't automatically make
a box filter the best or best looking filter. Pixels are not little
squares

hsyq8xg@gmail.com> wrote:

1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?

What were expecting? If you remove seven eighths of the data then seven
eighths of the data will be gone.

That's exactly what pixels are, in every camera I've ever heard of.
The light is projected on to the focal plane at "infinite" resolution
(ignoring the lense, arpeture, etc), and the CCD integrates the amount
of light falling on a bunch of little squares. IOW, the CCD is
precisely a box filter.

Of course, this isn't a real image, but box filtering is quite
physically accurate for integer ratios or large non-integer ratios.

It can produce stair-stepping, but then again, so can a real camera.

N wrote:
hsyq8xg@gmail.com> wrote:

...

1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?

...

What were expecting? If you remove seven eighths of the data then
seven eighths of the data will be gone.

Much less than 1/8 of the data remains.

(1024 X 768) / (8192 X 6144) = fraction remaining
786432 / 50331648 = 0.015625
One time when I was a child my mother sent me to the store to buy ten

Beryl wrote:
N wrote:
hsyq8xg@gmail.com> wrote:

...

1. Can you tell me of the best way to shrink a 8192X6144 size graphic
to
1024X768 size graphic without losing the interesting details?

...

What were expecting? If you remove seven eighths of the data then
seven eighths of the data will be gone.

Much less than 1/8 of the data remains.

(1024 X 768) / (8192 X 6144) = fraction remaining
786432 / 50331648 = 0.015625
One time when I was a child my mother sent me to the store to buy ten
pounds of potatoes. The bag was too heavy, so I took out nine pounds and
threw them away. When I got home I couldn't believe it when I could find
only one pound. I asked my mother how I could get them back, and she
told me to go back to where I threw them away and bring them back;
sadly, I couldn't find them.
Allen

On Apr 29, 12:39�am, hsyq...@gmail.com wrote:
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."

Sorry for this late reply.

3 example online:

A.www.PenangA1.com/png/1K.PNG

B.www.PenangA1.com/png/4K.PNG

C.www.PenangA2.com/png/ORI.PNG

The three examples above are fragments of a drawing that terragen
produced just a few days ago.

All three pictures were taken by the same screen capture program.

If you take a look at Picture C (ori.png), it's from the original
drawing ( resolution: 4096 X 3072 ), with file size of 37MB, in BMP
format. In Picture C you can see patches of green leaves distinctly,
arising from the brown wall.

Picture B represents a screenshot fragment of the 37MB drawing as my
desktop wallpaper (1024 X 768). As you can see from Picture B,
although much smaller than Picture C, the patches of green leaves are
still separated from the brown wall.

However, if you look at Picture A ... the patches of green leaves
kinda melt into the brown wall behind it. Picture A was from a
fragment of a 1024 X 768 picture (JPG format) that I shrunk from the
original 37 MB BMP drawing. When I shrunk it, I use 100% JPG quality,
with the "Lanczos" option.

The most important thing is that comparing Picture A with Picture
B ... as you can see, even if Picture A and Picture B were obtained
from pictures with the same dimension ( 1024 X 768 ), albeit different
pictures, the green leaf patches of Picture B can still be clearly
seen, while Picture A, the green leaves and brown wall are all mixed
up.

Any comment ??

aruzinsky wrote:
On Apr 29, 12:39�am, hsyq...@gmail.com wrote:
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."