strange grid pattern

Discussion in 'Digital Photography' started by sobriquet, May 22, 2012.

  1. sobriquet

    sobriquet Guest

    Hi.

    Does anyone have an explanation for the partial grid pattern visible in the background of this picture (consisting of horizontal and vertical lines)?

    http://i.imgur.com/EUJBA.jpg
    sobriquet, May 22, 2012
    #1
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  2. sobriquet

    sobriquet Guest

    On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    > On 2012-05-22 09:34:41 -0700, sobriquet <> said:
    >
    > >
    > > Hi.
    > >
    > > Does anyone have an explanation for the partial grid pattern visible in
    > > the background of this picture (consisting of horizontal and vertical
    > > lines)?
    > >
    > > http://i.imgur.com/EUJBA.jpg

    >
    > I am not sure that describing what you are seeing as a "partial grid
    > pattern" is quite correct.


    Well ok, no regular grid but rather an implied grid of irregularly spaced horizontal and vertical line segments.

    > Confirm that the areas I have marked are what you are talking about, so
    > we are on the same page.
    > < http://db.tt/MDPLIqNp >


    Yes, these lines.

    >
    > For now I can only guess that what you are seeing is some type of
    > aliasing artifact. I am sure that others will have a much better idea,
    > along with a possible fix.
    >
    >
    > --
    > Regards,
    >
    > Savageduck
    sobriquet, May 22, 2012
    #2
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  3. On 5/22/2012 2:21 PM, sobriquet wrote:
    > On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    >> On 2012-05-22 09:34:41 -0700, sobriquet<> said:
    >>
    >>>
    >>> Hi.
    >>>
    >>> Does anyone have an explanation for the partial grid pattern visible in
    >>> the background of this picture (consisting of horizontal and vertical
    >>> lines)?
    >>>
    >>> http://i.imgur.com/EUJBA.jpg

    >>
    >> I am not sure that describing what you are seeing as a "partial grid
    >> pattern" is quite correct.

    >
    > Well ok, no regular grid but rather an implied grid of irregularly spaced horizontal and vertical line segments.
    >
    >> Confirm that the areas I have marked are what you are talking about, so
    >> we are on the same page.
    >> < http://db.tt/MDPLIqNp>

    >
    > Yes, these lines.
    >
    >>
    >> For now I can only guess that what you are seeing is some type of
    >> aliasing artifact. I am sure that others will have a much better idea,
    >> along with a possible fix.
    >>
    >>
    >> --
    >> Regards,
    >>
    >> Savageduck

    >

    Interesting, try as I will I can only see one pattern that looks like a
    few small squares in out of focus top left area. It's surely some sort
    of aliasing. Is it visible at different resolutions?

    --
    Jim Silverton (Potomac, MD)

    Extraneous "not" in Reply To.
    James Silverton, May 22, 2012
    #3
  4. On 5/22/2012 2:47 PM, James Silverton wrote:
    > On 5/22/2012 2:21 PM, sobriquet wrote:
    >> On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    >>> On 2012-05-22 09:34:41 -0700, sobriquet<> said:
    >>>
    >>>>
    >>>> Hi.
    >>>>
    >>>> Does anyone have an explanation for the partial grid pattern visible in
    >>>> the background of this picture (consisting of horizontal and vertical
    >>>> lines)?
    >>>>
    >>>> http://i.imgur.com/EUJBA.jpg
    >>>
    >>> I am not sure that describing what you are seeing as a "partial grid
    >>> pattern" is quite correct.

    >>
    >> Well ok, no regular grid but rather an implied grid of irregularly
    >> spaced horizontal and vertical line segments.
    >>
    >>> Confirm that the areas I have marked are what you are talking about, so
    >>> we are on the same page.
    >>> < http://db.tt/MDPLIqNp>

    >>
    >> Yes, these lines.
    >>
    >>>
    >>> For now I can only guess that what you are seeing is some type of
    >>> aliasing artifact. I am sure that others will have a much better idea,
    >>> along with a possible fix.
    >>>
    >>>
    >>> --
    >>> Regards,
    >>>
    >>> Savageduck

    >>

    > Interesting, try as I will I can only see one pattern that looks like a
    > few small squares in out of focus top left area. It's surely some sort
    > of aliasing. Is it visible at different resolutions?
    >

    Can I add that opening with IrfanView does very little but Windows Photo
    Viewer and Paint show an overall square grid most apparent in Paint but
    switching to Full Screen almost removes the pattern.

    --
    Jim Silverton (Potomac, MD)

    Extraneous "not" in Reply To.
    James Silverton, May 22, 2012
    #4
  5. sobriquet

    sobriquet Guest

    On Tuesday, May 22, 2012 11:05:22 PM UTC+2, Alan Browne wrote:
    > On 2012-05-22 12:34 , sobriquet wrote:
    > >
    > > Hi.
    > >
    > > Does anyone have an explanation for the partial grid pattern visible in the background of this picture (consisting of horizontal and vertical lines)?
    > >
    > > http://i.imgur.com/EUJBA.jpg

    >
    > Can you post the original full size image (jpg or preferably raw)?
    >
    > Did you do anything with layers and not "flatten" the result before
    > posting the JPG.
    >
    > --
    > "Civilization is the limitless multiplication of unnecessary necessities."
    > -Samuel Clemens.


    No, it's just an image I encountered on a forum. I can't link to it, because the forum (www.photodrome.nl) changes url's all the time.
    sobriquet, May 22, 2012
    #5
  6. sobriquet

    Me Guest

    On 23/05/2012 9:28 a.m., sobriquet wrote:
    > On Tuesday, May 22, 2012 11:05:22 PM UTC+2, Alan Browne wrote:
    >> On 2012-05-22 12:34 , sobriquet wrote:
    >>>
    >>> Hi.
    >>>
    >>> Does anyone have an explanation for the partial grid pattern visible in the background of this picture (consisting of horizontal and vertical lines)?
    >>>
    >>> http://i.imgur.com/EUJBA.jpg

    >>
    >> Can you post the original full size image (jpg or preferably raw)?
    >>
    >> Did you do anything with layers and not "flatten" the result before
    >> posting the JPG.
    >>
    >> --
    >> "Civilization is the limitless multiplication of unnecessary necessities."
    >> -Samuel Clemens.

    >
    > No, it's just an image I encountered on a forum. I can't link to it, because the forum (www.photodrome.nl) changes url's all the time.
    >

    I'm going to make a guess that this was the result of image stacking to
    increase DOF. As well as the areas each side of the line being a bit
    darker or lighter, there seems to be a difference in focus.
    Me, May 22, 2012
    #6
  7. sobriquet

    sobriquet Guest

    On Tuesday, May 22, 2012 11:53:41 PM UTC+2, Savageduck wrote:
    > On 2012-05-22 14:28:30 -0700, sobriquet <> said:
    >
    > > On Tuesday, May 22, 2012 11:05:22 PM UTC+2, Alan Browne wrote:
    > >> On 2012-05-22 12:34 , sobriquet wrote:
    > >>>
    > >>> Hi.
    > >>>
    > >>> Does anyone have an explanation for the partial grid pattern visible in
    > >>> the background of this picture (consisting of horizontal and vertical
    > >>> lines)?
    > >>>
    > >>> http://i.imgur.com/EUJBA.jpg
    > >>
    > >> Can you post the original full size image (jpg or preferably raw)?
    > >>
    > >> Did you do anything with layers and not "flatten" the result before
    > >> posting the JPG.
    > >>
    > >> --
    > >> "Civilization is the limitless multiplication of unnecessary necessities."
    > >> -Samuel Clemens.

    > >
    > > No, it's just an image I encountered on a forum. I can't link to it,
    > > because the forum (www.photodrome.nl) changes url's all the time.

    >
    > So this is not your original work?


    No, it's not.

    >
    > In that case there are all sorts of potential issues, including your
    > lack of knowledge regarding the processing method & tools used by the
    > owner of the image.


    Well, I can contact the owner of the image if necessary, but that involves
    the hassle of registration at that forum.

    >
    > --
    > Regards,
    >
    > Savageduck
    sobriquet, May 22, 2012
    #7
  8. sobriquet

    sobriquet Guest

    On Wednesday, May 23, 2012 3:22:32 AM UTC+2, Savageduck wrote:
    > On 2012-05-22 15:07:12 -0700, sobriquet <> said:
    >
    > > On Tuesday, May 22, 2012 11:53:41 PM UTC+2, Savageduck wrote:
    > >> On 2012-05-22 14:28:30 -0700, sobriquet <> said:
    > >>
    > >>> On Tuesday, May 22, 2012 11:05:22 PM UTC+2, Alan Browne wrote:
    > >>>> On 2012-05-22 12:34 , sobriquet wrote:
    > >>>>>
    > >>>>> Hi.
    > >>>>>
    > >>>>> Does anyone have an explanation for the partial grid pattern visible in
    > >>>>> the background of this picture (consisting of horizontal and vertical
    > >>>>> lines)?
    > >>>>>
    > >>>>> http://i.imgur.com/EUJBA.jpg
    > >>>>
    > >>>> Can you post the original full size image (jpg or preferably raw)?
    > >>>>
    > >>>> Did you do anything with layers and not "flatten" the result before
    > >>>> posting the JPG.
    > >>>>
    > >>>> --
    > >>>> "Civilization is the limitless multiplication of unnecessary necessities."
    > >>>> -Samuel Clemens.
    > >>>
    > >>> No, it's just an image I encountered on a forum. I can't link to it,
    > >>> because the forum (www.photodrome.nl) changes url's all the time.
    > >>
    > >> So this is not your original work?

    > >
    > > No, it's not.
    > >
    > >>
    > >> In that case there are all sorts of potential issues, including your
    > >> lack of knowledge regarding the processing method & tools used by the
    > >> owner of the image.

    > >
    > > Well, I can contact the owner of the image if necessary, but that involves
    > > the hassle of registration at that forum.

    >
    > In that case I would suggest you have invested far too much of your
    > time in an image, which in its original form probably has no problems
    > at all.
    > ...but perhaps not as uploaded to that particular forum.
    >
    > You have downloaded an image you did not capture, and it has been
    > resized and compressed for web presentation. in all likelihood the
    > phenomenon is probably a type of compression artifact.


    Still, it doesn't look like typical jpg compression artifacts as
    far as I can see.

    >
    > When lifting images from the Web your expectations for a perfect image
    > should be lowered. The same applies to unofficial downloads of audio
    > and video files.


    Images don't have to be perfect. But I like to explore the web for images that
    I can use in my own photoshop compositions:

    http://i.imgur.com/Nnmpk.jpg

    >
    >
    > --
    > Regards,
    >
    > Savageduck
    sobriquet, May 23, 2012
    #8
  9. sobriquet

    Martin Brown Guest

    On 22/05/2012 19:47, James Silverton wrote:
    > On 5/22/2012 2:21 PM, sobriquet wrote:
    >> On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    >>> On 2012-05-22 09:34:41 -0700, sobriquet<> said:
    >>>
    >>>>
    >>>> Hi.
    >>>>
    >>>> Does anyone have an explanation for the partial grid pattern visible in
    >>>> the background of this picture (consisting of horizontal and vertical
    >>>> lines)?
    >>>>
    >>>> http://i.imgur.com/EUJBA.jpg
    >>>
    >>> I am not sure that describing what you are seeing as a "partial grid
    >>> pattern" is quite correct.

    >>
    >> Well ok, no regular grid but rather an implied grid of irregularly
    >> spaced horizontal and vertical line segments.
    >>
    >>> Confirm that the areas I have marked are what you are talking about, so
    >>> we are on the same page.
    >>> < http://db.tt/MDPLIqNp>

    >>
    >> Yes, these lines.
    >>
    >>>
    >>> For now I can only guess that what you are seeing is some type of
    >>> aliasing artifact. I am sure that others will have a much better idea,
    >>> along with a possible fix.


    >>>
    >>> Savageduck

    >>

    > Interesting, try as I will I can only see one pattern that looks like a
    > few small squares in out of focus top left area. It's surely some sort
    > of aliasing. Is it visible at different resolutions?


    I don't think it is aliasing. The source image is completely out of
    focus there with no sharp features to alias. The reason this quirk
    stands out is because there is no genuine high frequency component to
    hide it. The in focus insect makes it impossible to follow the lines
    although every one is present on the other side at a weaker level than
    on the side where it is most obvious.

    The features are sharp single pixel lines with adjacent ripples and not
    regularly spaced in terms of JPEG index or any other obvious sensor
    metric. My best guess is that some kind of anti-shake mechanism has
    moved the sensor during the exposure or there is some kind of subtle
    electronic interference occurring.

    For those wondering what all the fuss is about easily visible lines
    occur horizontally at (14, 604) (541,305) delta 300 pixels
    (183,111) (448, 816) (556, 272) (815, 778) delta 265, 112, 256
    taking top left as (0,0) and coordinates as (x,y)

    256 is the only one of these spacings that might be a memory related
    issue. The lines are accurately parallel to the sensor array and can be
    picked up with difficulty on any out of focus zone.

    It seems to me like the lines have a different exposure on either side
    so my instinct is some kind of anti-blur sensor movement or active IS
    lens affecting exposure. That or you were being illuminated by fairly
    high power pulsed radar at the time of taking the picture.

    --
    Regards,
    Martin Brown
    Martin Brown, May 23, 2012
    #9
  10. sobriquet

    sobriquet Guest

    On Wednesday, May 23, 2012 9:08:15 AM UTC+2, Martin Brown wrote:
    > On 22/05/2012 19:47, James Silverton wrote:
    > > On 5/22/2012 2:21 PM, sobriquet wrote:
    > >> On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    > >>> On 2012-05-22 09:34:41 -0700, sobriquet<> said:
    > >>>
    > >>>>
    > >>>> Hi.
    > >>>>
    > >>>> Does anyone have an explanation for the partial grid pattern visible in
    > >>>> the background of this picture (consisting of horizontal and vertical
    > >>>> lines)?
    > >>>>
    > >>>> http://i.imgur.com/EUJBA.jpg
    > >>>
    > >>> I am not sure that describing what you are seeing as a "partial grid
    > >>> pattern" is quite correct.
    > >>
    > >> Well ok, no regular grid but rather an implied grid of irregularly
    > >> spaced horizontal and vertical line segments.
    > >>
    > >>> Confirm that the areas I have marked are what you are talking about, so
    > >>> we are on the same page.
    > >>> < http://db.tt/MDPLIqNp>
    > >>
    > >> Yes, these lines.
    > >>
    > >>>
    > >>> For now I can only guess that what you are seeing is some type of
    > >>> aliasing artifact. I am sure that others will have a much better idea,
    > >>> along with a possible fix.

    >
    > >>>
    > >>> Savageduck
    > >>

    > > Interesting, try as I will I can only see one pattern that looks like a
    > > few small squares in out of focus top left area. It's surely some sort
    > > of aliasing. Is it visible at different resolutions?

    >
    > I don't think it is aliasing. The source image is completely out of
    > focus there with no sharp features to alias. The reason this quirk
    > stands out is because there is no genuine high frequency component to
    > hide it. The in focus insect makes it impossible to follow the lines
    > although every one is present on the other side at a weaker level than
    > on the side where it is most obvious.
    >
    > The features are sharp single pixel lines with adjacent ripples and not
    > regularly spaced in terms of JPEG index or any other obvious sensor
    > metric. My best guess is that some kind of anti-shake mechanism has
    > moved the sensor during the exposure or there is some kind of subtle
    > electronic interference occurring.
    >
    > For those wondering what all the fuss is about easily visible lines
    > occur horizontally at (14, 604) (541,305) delta 300 pixels
    > (183,111) (448, 816) (556, 272) (815, 778) delta 265, 112, 256
    > taking top left as (0,0) and coordinates as (x,y)
    >
    > 256 is the only one of these spacings that might be a memory related
    > issue. The lines are accurately parallel to the sensor array and can be
    > picked up with difficulty on any out of focus zone.
    >
    > It seems to me like the lines have a different exposure on either side
    > so my instinct is some kind of anti-blur sensor movement or active IS
    > lens affecting exposure. That or you were being illuminated by fairly
    > high power pulsed radar at the time of taking the picture.
    >
    > --
    > Regards,
    > Martin Brown


    Thx for the detailed explanation.
    From what I can tell on the forum, the images were taken with a Canon 600D with
    a 100 mm macro objective at f/11 and 1/100s.
    sobriquet, May 23, 2012
    #10
  11. sobriquet

    Robert Coe Guest

    On Tue, 22 May 2012 11:03:27 -0700, Savageduck
    <savageduck1@{REMOVESPAM}me.com> wrote:
    : On 2012-05-22 09:34:41 -0700, sobriquet <> said:
    :
    : >
    : > Hi.
    : >
    : > Does anyone have an explanation for the partial grid pattern visible in
    : > the background of this picture (consisting of horizontal and vertical
    : > lines)?
    : >
    : > http://i.imgur.com/EUJBA.jpg
    :
    : I am not sure that describing what you are seeing as a "partial grid
    : pattern" is quite correct.
    : Confirm that the areas I have marked are what you are talking about, so
    : we are on the same page.
    : < http://db.tt/MDPLIqNp >
    :
    : For now I can only guess that what you are seeing is some type of
    : aliasing artifact. I am sure that others will have a much better idea,
    : along with a possible fix.

    My guess is a sloppy compression algorithm that results in one or more rows or
    columns of pixels being jettisoned. In effect, it's roundoff error.

    Bob
    Robert Coe, May 24, 2012
    #11
  12. sobriquet

    Rob Guest

    On 23/05/2012 5:08 PM, Martin Brown wrote:
    > On 22/05/2012 19:47, James Silverton wrote:
    >> On 5/22/2012 2:21 PM, sobriquet wrote:
    >>> On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    >>>> On 2012-05-22 09:34:41 -0700, sobriquet<> said:
    >>>>
    >>>>>
    >>>>> Hi.
    >>>>>
    >>>>> Does anyone have an explanation for the partial grid pattern
    >>>>> visible in
    >>>>> the background of this picture (consisting of horizontal and vertical
    >>>>> lines)?
    >>>>>
    >>>>> http://i.imgur.com/EUJBA.jpg
    >>>>
    >>>> I am not sure that describing what you are seeing as a "partial grid



    I have had this sort of thing its just the image has been corrupted and
    the original is more than likely fine.

    Mine have come from a slow transfer from media to media or multiple
    transfers.
    Rob, May 24, 2012
    #12
  13. sobriquet

    Martin Brown Guest

    On 24/05/2012 05:05, Rob wrote:
    > On 23/05/2012 5:08 PM, Martin Brown wrote:
    >> On 22/05/2012 19:47, James Silverton wrote:
    >>> On 5/22/2012 2:21 PM, sobriquet wrote:
    >>>> On Tuesday, May 22, 2012 8:03:27 PM UTC+2, Savageduck wrote:
    >>>>> On 2012-05-22 09:34:41 -0700, sobriquet<> said:
    >>>>>
    >>>>>>
    >>>>>> Hi.
    >>>>>>
    >>>>>> Does anyone have an explanation for the partial grid pattern
    >>>>>> visible in
    >>>>>> the background of this picture (consisting of horizontal and vertical
    >>>>>> lines)?
    >>>>>>
    >>>>>> http://i.imgur.com/EUJBA.jpg
    >>>>>
    >>>>> I am not sure that describing what you are seeing as a "partial grid

    >
    >
    > I have had this sort of thing its just the image has been corrupted and
    > the original is more than likely fine.
    >
    > Mine have come from a slow transfer from media to media or multiple
    > transfers.


    No. A corrupted JPEG stream looks entirely different and *must* change
    state over a JPEG 8x8 block boundary. These don't.

    --
    Regards,
    Martin Brown
    Martin Brown, May 24, 2012
    #13
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