model page picture preview

Discussion in 'Bug Reporting' started by lsuess, Aug 18, 2010.

Is turning off the picture preview scaleup a good idea?

  1. yes

  2. no

Results are only viewable after voting.
  1. lsuess
    lsuess New Member
    I've run across an interesting problem regarding the standard picture preview on the model pages:

    Because the preview picture is of fixed width , high and slim pictures
    have to be pretty big so that they aren't scaled up and get ugly blurred.

    (example: tml)
    In fact in my case (I think that thing above falls under a reasonable picture aspect ratio) the size of a screenshot from screentop to screenbottom isn't sufficient to prevent blowup.

    Because the upscaling (in the auto-resized) preview always blurrs the picture I suggest turning it off leaving downscaling still on of course.
    Is there anybody with me with that?
    Please vote.
  2. Tommy_2Tall
    Tommy_2Tall New Member

    I've noticed the same problem with scaling in certain situations.

    I agree with you that scaling up a small preview to fit that space is not optimal as the resulting scaled image can sometimes be rather hideous.

    However I also see the problems this could give the webmaster(s) here;
    the larger images would still need the automatic downscaling so by some means the webserver would have to check if the picture is smaller or larger than the reserved space and act based on that result (autoscale if larger, leave at 1:1 if smaller than the reserved space).

    I don't know how much work would be needed to fix that but if it's possible to only scale down images that are larger than the reserved space I'm all for it. :)
  3. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    I think at most shapeways should tell us the optimal size. Maybe at upload have a "scale to such and such by such and such" button. But overall should be in the hands of the shop owner.
  4. lsuess
    lsuess New Member
    @Tommy 2Tall

    I think it would be no big deal of programming effort to only scale down images that are larger than the reserved space.


    I don't see what do you mean with a "scale to such and such by such and such" button?

    They actually told us the optimal picture size once!
    On the page "how to photograph your designs page" or so (I can't find it anymore, just digged that out of my notes) someone from shapeways wrote:
    >> Please upload photographs in the format: 450x324 or 700x519 <<

    But why exactly these?! (aspect ratios 1.3888 &. 1.3487)

    Up until now I often used 640x480 (4/3) or bigger arbitrary sized screenshots.
    Uploaded in landscape format this always get scaled down nicely (i'am talking about the the view in the non-clicked picture preview, just to make sure).

    But in panel format a with of 333 pixels (my example above) isn't enough.
    Note that the first recommended format above 450x324 would also get blown up if uploaded in panel format.
  5. lsuess
    lsuess New Member
    I've acountered additional problems.

    No matter what I do I get a huge loss in image quality after image upload.
    (again portrait format, but this time both in the preview AND when I click on it)

    First: My upload was bigger than the preview image, so it shouldn't loose sharpness.
    But that is not the case. The preview is more blurred although downscaled.
    I am betting on a bad scaledown algorithm here because the blurring is inhomogenous
    on some upload widths I tried**.

    But that was only the less serious problem.
    If I click on it to get a better view it gets even smaller and equally blurred.
    I suppose that should never happen.
    As I understand it when one clicks on the preview picture one is supposed to get the
    original uploaded picture 1:1 often called "actual pixels view".

    I tried widths of 700pix, 640pix, 1024pix, all with the same result.
    (It was an exported vectorgraphics file where the blurring was especially good visible on sharp edges.
    All of the versions had an aspect ratio of width*highth = 1024*1174)

    Finally I tried to prevent the scaling with uploading exactly the shown size:
    I right click-downloaded the picture preview and the "clicked view".
    Both had the same size so I guess I can only access one of these two views.

    I got a width of 428 pixels, scaled my picture on my pc down to this with (checked quality) and uploaded it. This still lead to blurring but most of it was in the center. The sides where sharper (** inhomogenous blurring as mentioned before)

    Strange thing is that the autogenerated picture blows up way bigger to a width of 700 pixels when I click on it.

    summing up there are two problems plus the one from before:
    # scaledown for preview doesn't perform well
    # the high quality (clicked) view doesn't show the original uploaded images actual pixels and is sometimes even smaller then the preview image
    # high aspect ratio portrait pictures are blown up to fit the width