Shrinking a picture --- and it becomes blur !!

Discussion in 'Digital Photography' started by hsyq8xg@gmail.com, Apr 29, 2008.

  1. Guest

    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
    , Apr 29, 2008
    #1
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  2. N Guest

    <> wrote in message
    news:...
    > 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.
    N, Apr 29, 2008
    #2
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  3. wrote:
    > 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>
    > 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
    Andrew Morton, Apr 29, 2008
    #3
  4. Guest

    On Apr 29, 4:39 pm, 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


    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?
    , Apr 29, 2008
    #4
  5. 3.hu Guest

    On Apr 28, 11:39 pm, 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



    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.........
    3.hu, Apr 29, 2008
    #5
  6. k Guest

    <> wrote in message
    news:...
    | 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 !!

    | 2. Which software do you recommend to carry out the shrinking
    | operation?

    anything with the right algorithm, and the algoriothm makes all the
    difference


    ...and downsizing is quite, quite different from upsizing!



    a basic primer on algorithm for resizing can be found here: (grr.. the web
    site's gone!)
    http://web.archive.org/web/20060409125805/http://www.interpolatethis.com/int
    erp.html

    and some comparisons
    http://www.cambridgeincolour.com/tutorials/image-resize-for-web.htm
    http://www.cambridgeincolour.com/tutorials/digital-photo-enlargement.htm
    k, Apr 29, 2008
    #6
  7. Guest

    On Apr 29, 8:13 pm, bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
    > wrote:
    > > On Apr 29, 4:39 pm, 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 8)
    > 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...
    , Apr 29, 2008
    #7
  8. Duddits Guest

    On Mon, 28 Apr 2008 23:39:48 -0700 (PDT), 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?
    >
    >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
    Duddits, Apr 29, 2008
    #8
  9. Sagiv Guest

    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.
    Sagiv, Apr 29, 2008
    #9
  10. aruzinsky Guest

    On Apr 29, 12:39 am, 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."
    aruzinsky, Apr 29, 2008
    #10
  11. KatWoman Guest

    <> wrote in message
    news:...
    > 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


    are you setting to bicubic sharper??
    I heard this is a better option to tick for sizing down
    what if your original is not jpeg (compressed) but instead saved as tiff
    uncompressed?
    then you are not compressing an already compressed format

    are you choosing high or maximum for quality of the downsized jpg?
    KatWoman, Apr 29, 2008
    #11
  12. bugbear <bugbear@trim_papermule.co.uk_trim> writes:

    >> Or try the "Lanczos" algorithm


    >Since the downsize is an exact integer (factor of 8)
    >I'm not sure Lanczos (or anything "better" than bilinear)
    >would help.


    The fact that the downsize ratio is an integer factor means it's easy to use a box filter
    for the downsizing and get "not bad" results. That doesn't mean Lanczos would not be better
    yet. A box filter still produces a fair amount of aliasing due to letting through input
    image frequency components that are above the Nyquist limit for the output resolution.
    Lanczos is better at attenuating these frequencies and suffers less aliasing artifacts. At
    the same time, it's better at retaining frequencies just below Nyquist that a box filter
    attenuates more than necessary.

    Now, a reasonable-sized Lanczos downsampling filter will cost you more time than a box
    filter - but it should be small compared to the original render time.

    Dave
    Dave Martindale, Apr 30, 2008
    #12
  13. Marco Tedaldi <> writes:

    >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.


    I think this comes from a time years ago when someone observed that
    resizing images in multiple small steps *in Photoshop* gave a result
    that looked better than doing the operation in a single step. But back
    then, Photoshop had only one choice of bicubic resizing algorithm, and
    from my observations of applying it repeatedly, I think each
    application results in a little bit of high-frequency boost. The
    result of many small steps has more sharpening than the result of one
    resize by a larger factor. But it's not clear that you couldn't get
    the same result from one resize step followed by one sharpening step
    (with suitable parameter settings).

    If you're familiar with bicubic polynomial resampling, there is one
    free parameter that you get to choose, the coefficient of the cubic
    term. A value of -0.5 gives a frequency response (Fourier transform)
    that has zero slope at zero frequency, with no high-frequency boost. A
    value of -0.75 gives second-derivative continuity instead of only
    first-derivative continuity at t=1 (the splice point between
    polynomials). And a value of -1.0 matches the slope of a sinc function
    at t=1. The latter two provide some high-frequency boost (i.e.
    sharpening), and my experiments suggest the bicubic filter in older
    Photoshop used something like -0.75. (More recent versions have
    several choices of "bicubic".

    >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 you used a "perfect" downsizing filter, which kept all frequencies
    below Nyquist and discarded all frequencies above it, you could
    downsize in many small steps or one large step and get exactly the same
    result. But downsampling filters are not perfect, particularly not
    bilinear or bicubic, so the multi-step downsizing can give different
    results than single-step. It might well be less accurate, but less
    accurate can still look better.

    Dave
    Dave Martindale, Apr 30, 2008
    #13
  14. [A complimentary Cc of this posting was sent to
    Dave Martindale
    <>], who wrote in article <fv8nif$107$>:
    > >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 you used a "perfect" downsizing filter, which kept all frequencies
    > below Nyquist and discarded all frequencies above it, you could
    > downsize in many small steps or one large step and get exactly the same
    > result. But downsampling filters are not perfect, particularly not
    > bilinear or bicubic, so the multi-step downsizing can give different
    > results than single-step. It might well be less accurate, but less
    > accurate can still look better.


    [There is no useful meaning of "accurate" w.r.t. downsampling, so
    your last sentence does not make much sense.]

    There are two major advantages of downsampling in steps:

    a) The aliasing may send high frequencies to high frequencies, but
    would never alias to small frequencies;

    b) To get a reasonable result, one needs to dump high frequencies
    (to decrease both noise, and aliasing), and have as horizontal
    MTF as possible at low frequencies. Doing this in one step would
    require a very complicated convolution kernel.

    But if you do in multiple steps, you can apply a minimal filter
    (e.g. 5x5) on each step, and get a very reasonable total result.

    Hope this helps,
    Ilya

    P.S. I'm sitting on an "almost finished" script which chooses
    "optimal" parameters in (a) and (b). However, due to major
    idiosyncrasies of ImageMagick (yes, I looked into the source!)
    the "last touches" are postponed indefinitely...
    Ilya Zakharevich, Apr 30, 2008
    #14
  15. In rec.photo.digital wrote:
    > On Apr 29, 8:13?pm, bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
    >> wrote:
    >> > On Apr 29, 4:39 pm, 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 8)
    >> 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...


    I experimented with downsizing in Irfanview with the Lanczos option
    and found that doing it in a number of steps never produced better
    results, and sometimes produced worse ones.

    --
    Chris Malcolm DoD #205
    IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
    [http://www.dai.ed.ac.uk/homes/cam/]
    Chris Malcolm, Apr 30, 2008
    #15
  16. On Apr 29, 1:37 pm, Marco Al <> wrote:

    > 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


    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.

    At exact integer ratios is pretty much exactly what using the same
    sized CCD chip with fewer (ie larger) pixels would do.

    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.

    -Ed

    --
    (You can't go wrong with psycho-rats.)(http://mi.eng.cam.ac.uk/~er258)

    /d{def}def/f{/Times s selectfont}d/s{11}d/r{roll}d f 2/m{moveto}d -1
    r 230 350 m 0 1 179{ 1 index show 88 rotate 4 mul 0 rmoveto}for/s 12
    d f pop 235 420 translate 0 0 moveto 1 2 scale show showpage
    Edward Rosten, Apr 30, 2008
    #16
  17. Dave Guest

    On Wed, 30 Apr 2008 15:59:52 -0500, Allen <> wrote:

    >Beryl wrote:
    >> N wrote:
    >>> <> 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



    Stupid..! You should have kept the ten pounds with the one pound
    and carry all 11 pounds. You should never pick on a digital career
    when you grow up.
    (clever people never throw potatoes away, anyway.)
    Dave, Apr 30, 2008
    #17
  18. nospam Guest

    In article <>, Pico wrote:

    > (Didn't Steve Jobs' R&D people have postscript display in their neXt OS?)


    nextstep/openstep used display postscript and os x uses pdf.
    nospam, May 1, 2008
    #18
  19. Guest

    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, 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."
    , May 1, 2008
    #19
  20. pg Guest

    On May 1, 8:12 am, wrote:
    > 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



    Picture C should be www.PenangA1.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, 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."
    pg, May 1, 2008
    #20
    1. Advertising

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