1 2 Previous Next 54 Replies Latest reply: Oct 21, 2012 6:05 AM by Hudechrome RSS

    Maybe a bug in prospective crop tool?

    Mullen_Studio

      A very strange bug. My photoshop is extended CS6 13.0.1, x64, running on Win7 and Win8 (I have tested on different computers to make sure it's not the computer or system's problem).

       

      Here is my source image, taken from EOS T3i

      http://dl.dropbox.com/u/68132141/IMG_1846.JPG

      Here is the image resized by photoshop. The bug also happens for this resized version. However, I give the original version just in case.

      IMG_1846_Resize.jpg

      What I want to do is to get the screen shot of upper screen, That's the area I want to crop. So what I did is selecting the prospective crop tool, clicking the 4 corners of the upper screen (without black border), from top left to top right, ccw order. Then I zoomed in and further adjusted the the positions of the 4 corners, clicked the accept button.

       

      This is what I expected (it's from another photo I took, and this photo, as well as all other photos, has no problem with perspective crop tool)

      IMG_1846_Right.png

      However, for the particular one source photo I provided above, it always give a totally wrong result, like

      IMG_1846_Wrong.jpg

      There's distrotion on the right side, as well as some white space.

       

      Is this a bug, or did I missed some key points?

        • 1. Re: Maybe a bug in prospective crop tool?
          Curt Y Community Member

          It looks like a GPU problem.  Have you updated the drivers for Win8?  If there is such a thing yet.

           

          Turn off the "use graphics processer" in preferences/performance.  If that helps it is the driver.

          • 2. Re: Maybe a bug in prospective crop tool?
            charles badland Community Member

            I see what you are seeing, and then some. Some of my Perspective Crop tests became extremely distorted.

            • 3. Re: Maybe a bug in prospective crop tool?
              Mullen_Studio Community Member

              The Win8 laptop uses intel graphic card. It's the latest driver, and the driver has problem (flickering in working area, seems that one of the double buffers can't be rendered and keep black). That's why I also tested on another computer (Win7sp1x64, NV GTX 460, 306.97), and got the same result.

              The strange thing is that that source image is the only one I meet this issue.

              Btw, turn off hardware acceleration (and restart photoshop) can't solve the problem

              • 4. Re: Maybe a bug in prospective crop tool?
                Mullen_Studio Community Member

                Yes, sometime the distrotion can be extremely, and sometime there's a popup dialog says "Could not use the perspective crop tool because the center point is not correctly placed or the corners are not properly selected"

                • 5. Re: Maybe a bug in prospective crop tool?
                  R_Kelly Community Member

                  I can actually see that distortion somewhat in the original photo.

                   

                  See if the following gives you better results:

                   

                  1. draw the perspective crop

                   

                  p1.jpg

                   

                  2. extended the sides of the crop

                   

                  p2.jpg

                   

                  3. Then use the regular crop tool  and you might have to apply some correction with the Filter>Lens Correction filter

                   

                   

                  p3.jpg

                   

                   

                  p4.jpg

                  • 6. Re: Maybe a bug in prospective crop tool?
                    Mullen_Studio Community Member

                    My question is not how to deal with this photo (because I've already got what I want from another photo)

                    My question is whether this is some unknown bug in photoshop, because it's so strange.

                    However, thank you anyway.

                    • 7. Re: Maybe a bug in prospective crop tool?
                      station_two Community Member

                      No, it's not "a  bug"; PEBKAC.

                       

                      It's the laws of Physics, of which Optics is an important part.

                      • 8. Re: Maybe a bug in prospective crop tool?
                        Noel Carboni Community Member

                        I'm going to side with Mullen_Studio on this one and say it's a bug, plain and simple. 

                         

                        If one places the Crop Tool edges on the bezel just outside the image the result is markedly better.

                         

                        ScreenGrab_10_19_2012_003140.jpg

                         

                        ScreenGrab_10_19_2012_003155.jpg

                         

                        -Noel

                        • 9. Re: Maybe a bug in prospective crop tool?
                          station_two Community Member

                          Your solution highlights the problem with the OP's approach, Noel.  You took into consideration the laws of Optics.

                           

                          The image needs enough room to accomodate the DOUBLE perspective correction necessary to fix this image, the OP's approach does not allow for that.

                           

                          The double distortion takes this exercise into the realm of polishing a turd, beyond simple perspective correction.

                          • 10. Re: Maybe a bug in prospective crop tool?
                            Noel Carboni Community Member

                            Sorry, but I'm just not seeing a logical distinction between placing the crop edges at the corner of the light part of the image vs. at the corners of the bezel.  If you're really seeing the reason here, please enlighten us, as you would children unworthy of your presence but asking for a handout anyway.

                             

                            About the only thing I can see special about selecting the exact corners of the light part is that the corners are very nearly on the same horizontal line.

                             

                            Rotating the image just 1 degree before using the perspective crop tool avoids the curvature entirely.

                             

                            It's a BUG, possibly because of loss of math precision owing to the corner points being on the same horizontal line.

                             

                            -Noel

                            • 11. Re: Maybe a bug in prospective crop tool?
                              R_Kelly Community Member

                              Did you try the same thing a earlier version of photoshop to see if cs6 behaves different?

                               

                              It's hard for me to say it's a bug if it only happens on one particular image.

                               

                              Anyway i'm getting the same results in photoshop 7 using the fullsize jpeg from dropbox as i do in photoshop cs6.

                              • 12. Re: Maybe a bug in prospective crop tool?
                                R_Kelly Community Member

                                Well there may come a time when you only have one image and no others of the same subject.

                                 

                                Since we haven't seen the other images that it does work on, i don't know if it's a glitch in cs6 or the particular image.

                                (not that what i think really matters, but just something to consider)

                                • 13. Re: Maybe a bug in prospective crop tool?
                                  ssprengel Community Member

                                  I agree it is a bug with CS6.  It works as expected in CS5.

                                   

                                  The problem is much worse if you rotate the crop box to align it with the image before moving each corner inwards.

                                   

                                  Initial crop box dragged around the full extent of the image:

                                  2012-10-19_012312.jpg

                                   

                                  Rotated crop box without resizing or moving the corners:

                                  2012-10-19_012344.jpg

                                   

                                  Corners moved to match the area to be cropped:

                                  2012-10-19_012438.jpg

                                   

                                  Crop applied:

                                  2012-10-19_012500.jpg

                                  Maybe I don't understand how the perspective-crop tool is supposed to work, but this result seems totally wrong to me.

                                  • 14. Re: Maybe a bug in prospective crop tool?
                                    Mullen_Studio Community Member

                                    Let me provide another photo, since this time resizing affects the result, I only give the original size version by dropbox.

                                    http://dl.dropbox.com/u/68132141/IMG_1844_Mark.jpg

                                    This file has been edited. I draw 4 red crosses to mark the positions of the corners of the problemetic photo. If you follow the corners of the upper screen, the prospective crop gives correct result. But if you follow the red crosses, you can find the problem appears (it can be checked by the crosses position).

                                    • 15. Re: Maybe a bug in prospective crop tool?
                                      station_two Community Member

                                      Noel Carboni wrote:

                                       

                                      ...please enlighten us, as you would children unworthy of your presence but asking for a handout anyway...    

                                       

                                      That's totally uncalled for, and I'm not biting.

                                      • 16. Re: Maybe a bug in prospective crop tool?
                                        station_two Community Member

                                        For anyone interested, R_Kelly has shown the right approach in post #5.

                                         

                                        Whether the crop tool can incorporate the various steps in one fell swoop we need to hear from the Adobe gurus who write the code.  Personally, I am not so bold as to expect it, but who am I to judge.

                                        • 17. Re: Maybe a bug in prospective crop tool?
                                          ssprengel Community Member

                                          If a first perspective crop is used to only rotate the image—no resizing by dragging the corners, then used again, to correct the perspective, it seems to work. 

                                           

                                          It also seems to work if the image is straightened the old-fashioned way, using the ruler and then arbitrary rotation, before using the perspective crop tool to correct perspective.

                                          • 18. Re: Maybe a bug in prospective crop tool?
                                            Noel Carboni Community Member

                                            station_two wrote:

                                             


                                            That's totally uncalled for

                                             

                                            As was your language; that was my point.  To avoid provocative answers, avoid nasty prods.

                                             

                                            Mullen_Studio has every right to expect this tool to straighten that image whether done in one or two steps, and it was very nice of him to bring it up here so that Adobe would know about it and might even try to fix it.  Belittling a person for doing that encourages him not to come back, and I for one think he did an excellent job of reporting a reproducible problem.

                                             

                                            The only thing special about this image is that the upper-left and lower-right corners of the DS screen are aligned almost perfectly horizontally.  It seems to me that those coordinates being coincidentally close together might be fouling up the math Adobe is doing in determining the repositioning of the pixels.  Something like a divide-by-zero error or loss of precision because of a very large or very small intermediate math product.  It can probably be fixed quite quickly and easily.

                                             

                                            I hope that Mullen_Studio will leave his image online at the location shown for a while, so that the Adobe people can download it and have a look at that bug.

                                             

                                            -Noel

                                            • 19. Re: Maybe a bug in prospective crop tool?
                                              Noel Carboni Community Member

                                              ssprengel wrote:

                                               

                                              It works as expected in CS5.

                                               

                                              Not from what I can see.  For me Phootshop CS5 emitted this error:

                                               

                                              ScreenGrab_10_19_2012_134218.jpg

                                               

                                              Moving the points out a bit averted that error but then yielded a crop that's more curved than the results shown above:

                                               

                                              CurvedResult.jpg

                                               

                                              -Noel

                                              • 20. Re: Maybe a bug in prospective crop tool?
                                                ssprengel Community Member

                                                The first half-a-dozen times I tried it in CS5 it worked ok so I thought it was ok, but now it is not working about 75% of the time.  I occasionally get the Center Point error, but usually it is just a little curved with extra background color at the right and bottom.

                                                 

                                                It seems to matter where the corners are precisely placed, as Noel said, like a rounding error, and perhaps the curvature comes from the error of the center points on the line segments being different than the error of the corners.  Mathematically, a perspective crop is just a special case of a warp with straight sides, and with a warp you can get curvature, so if there is some error in the coordinates that could be the cause.  It doesn’t explain why the background color is getting filled in on the right and bottom, though, except that not all the computations have the error so the result has a misalignment of the warped foreground and the rectangular area within it must fit, requiring transparent areas on the right and lower sides to get filled in with something.

                                                 

                                                I thought for a while that it mattered which corner I started with, because using the lower-left one worked most of the time, but now it isn’t, either, so I think it was just starting with a particular corner slightly influenced where I placed the corners which varies slightly because I am working with the image at 16.67% zoom, and while I try to place the points inside the thin black border of the screen, to better detect when it’s curved, sometimes they aren’t all in the black.

                                                 

                                                If there is a setting in CS5 or CS6 that says whether to make things snap to a grid or magnetic to borders that can be turned on and off, maybe that will affect things, but I’m not finding that in CS5, although Noel is much more the expert in PS than I am.

                                                • 21. Re: Maybe a bug in prospective crop tool?
                                                  Hudechrome Community Member

                                                  This crop tool will never match the simplicity and ease of a crop tool plus a trim tool in analog work. Even a straight edge and a razor is easier.

                                                   

                                                  I hate the crop tool in CS6. Things neither work as they have i.e. the easiest, consistent path to use, or they don't work at all. Take the auto centering. There is a check box to not center. It makes no difference checked or unchecked.

                                                   

                                                  The crop box does not disappear when the crop is finished, and if you are off one or two pixels you do not see it until you navigate to a different tool to eliminate the box, which is too late.

                                                   

                                                  I hate the crop tool! It is too cute by half! No, less than half.

                                                   

                                                  I haven't seem errors this big in the perspective crop tool but I've seen enough to never use it.

                                                   

                                                  But it can actually be worse. DxO just offered a "nifty" app which includes a sophisticated crop tool.

                                                   

                                                  Awful.

                                                  • 22. Re: Maybe a bug in prospective crop tool?
                                                    Noel Carboni Community Member

                                                    Hudechrome wrote:

                                                     

                                                    There is a check box to not center. It makes no difference checked or unchecked.

                                                     

                                                    Oh, geez, if that checkbox didn't work for me I'd surely be ranting.

                                                     

                                                    Lawrence, try this:

                                                     

                                                    1.  Open Photoshop and open exactly one image.

                                                    2.  Choose the Crop Tool

                                                    3.  Click the Gear icon and uncheck Auto Center Preview.

                                                    4.  Close the document, and close Photoshop (gracefully).

                                                     

                                                    Does it stick for future crops?

                                                     

                                                    -Noel

                                                    • 23. Re: Maybe a bug in prospective crop tool?
                                                      station_two Community Member

                                                      Noel Carboni wrote:

                                                       

                                                      station_two wrote:

                                                       


                                                      That's totally uncalled for

                                                       

                                                      As was your language; that was my point.  To avoid provocative answers, avoid nasty prods.

                                                       

                                                      Mullen_Studio has every right to expect this tool to straighten that image whether done in one or two steps, and it was very nice of him to bring it up here so that Adobe would know about it and might even try to fix it.  Belittling a person for doing that encourages him not to come back, and I for one think he did an excellent job of reporting a reproducible problem...

                                                       

                                                       

                                                      "Belittle anyone"??

                                                       

                                                      I'll give you the benefit of the doubt and assume that what you find objectionable was the phrase "polishing a turd" in which case that would just point to your lack of famliarity with that particular standard expression in the cut-throat business that is the digital image retouching field, where it has become practically a term of art by virtue of its frequency of use.

                                                       

                                                      The image in question had not only simple perspective distortion in one plane.  There was multiple perspective distortion already in the image being displayed on the screen of the device being photographed, and there was additional distortion introduced by the angle of the camera with which the portable device was photographed at an angle from above.

                                                       

                                                      Under those conditions, the attempt to correct multiple perspective and lens distortion in one go with the crop tool falls squarely in what digital image retouchers see as the thankless art of "polishing a turd".

                                                       

                                                      https://www.google.com/webhp#hl=en&sclient=psy-ab&q=polishing+a+turd+quote&oq=%22polishing +a+turd%22&gs_l=hp.1.1.0l2j0i30j0i10i30.0.0.2.34259.0.0.0.0.0.0.0.0..0.0.les%3B..0.0...1c. CkHgRnh62RQ&pbx=1&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.&fp=5fc5e948d96e0b0c&bpcl=35466521&biw=1 280&bih=631

                                                      • 24. Re: Maybe a bug in prospective crop tool?
                                                        Noel Carboni Community Member

                                                        No, post 7 is what I found offensive. 

                                                         

                                                        -Noel

                                                        • 25. Re: Maybe a bug in prospective crop tool?
                                                          station_two Community Member

                                                          Then both of us wasted our time dealing with this.  (This forum needs a good eye-roll emoticon.)

                                                          • 26. Re: Maybe a bug in prospective crop tool?
                                                            conroy Community Member

                                                            station_two wrote:

                                                             

                                                            [...] the attempt to correct multiple perspective and lens distortion in one go with the crop tool falls squarely in what digital image retouchers see as the thankless art of "polishing a turd".

                                                             

                                                            Can you back up that claim of lens distortion with annotations to the image? I see no lens distortion in the original IMG_1846.JPG, only focal blur. There's undoubtedly a bug in Photoshop's perspective correction. A piece of freeware can do the job as shown below.

                                                             

                                                            IMG_1846-straightened-and-cropped.png

                                                            • 27. Re: Maybe a bug in prospective crop tool?
                                                              Noel Carboni Community Member

                                                              station_two wrote:

                                                               


                                                              both of us wasted our time

                                                               

                                                              Speak for yourself.

                                                               

                                                              -Noel

                                                              • 28. Re: Maybe a bug in prospective crop tool?
                                                                station_two Community Member

                                                                I always do:  in my view, we both wasted our time over this trifle.  You may have a different view of the value of your own time.  I can't speak to that.

                                                                • 29. Re: Maybe a bug in prospective crop tool?
                                                                  station_two Community Member

                                                                  conroy,

                                                                   

                                                                  Sorry; I hadn't seen your post until just now.

                                                                   

                                                                  You are more than knowledgeable enough to see for yourself in the OP image the various planes and angles involved in making that photograph.  You can't convince me otherwise.

                                                                   

                                                                  Glad you can solve the problem with free software to a degree that satisfies you.  I'm sure the OP and others might be interested in knowing what that software is (personally, I'm not, as I don't see myself attempting to fix this little unpolished gem or others like it; but that's neither here nor there.)

                                                                   

                                                                  On the other hand, I can't see why I would be adverse to Adobe fixing the bug you and others see, even if it doesn't affect me.  It's not like my opinion on the issue were going to prevent Adobe from doing so.

                                                                  • 30. Re: Maybe a bug in prospective crop tool?
                                                                    conroy Community Member

                                                                    station_two wrote:

                                                                     

                                                                    conroy,

                                                                     

                                                                    Sorry; I hadn't seen your post until just now.

                                                                     

                                                                    You are more than knowledgeable enough to see for yourself in the OP image the various planes and angles involved in making that photograph.  You can't convince me otherwise.

                                                                     

                                                                    Yes, I see the perspective. I already said that I see it and focal blur. But you said the image has a problem of perspective and a problem of lens distortion. I said that I don't see this additional lens distortion and requested that you identify it. You've replied without addressing the lens distortion. Please show the lens distortion.

                                                                    • 31. Re: Maybe a bug in prospective crop tool?
                                                                      Noel Carboni Community Member

                                                                      Station_two is apparently trying to save face for making a snap judgment early on that turned out to be unjustified.  There may be an ever so slight curvature in the subject edges, but we've ultimately proven quite graphically that it has nothing to do with the problem, which turns out to be a Photoshop bug / weirdity. 

                                                                       

                                                                      Why a perpective correction tool that can only have straight edges should be able to introduce curvature is beyond me, but Adobe moves in mysterious ways.  Perhaps logic is shared behind the scenes with the Warp function.

                                                                       

                                                                      Knowing that the trouble seems to stem from diagonal corners being on almost the same coordinate vertically, It's not at all hard to come up with an example with straight lines that can be used to demonstrate problems.

                                                                       

                                                                      StraightEdges.png

                                                                       

                                                                      And as it turns out the problem DID turn out to be between keyboard and chair.  Just a different chair than was originally implied. 

                                                                       

                                                                      -Noel

                                                                      • 32. Re: Maybe a bug in prospective crop tool?
                                                                        conroy Community Member

                                                                        Noel Carboni wrote:

                                                                         

                                                                        Station_two is apparently trying to save face for making a snap judgment early on that turned out to be unjustified.

                                                                         

                                                                        I know, but I wanted to see him wriggle on the hook for a little longer.

                                                                         

                                                                         

                                                                        Noel Carboni wrote:

                                                                         

                                                                        There may be an ever so slight curvature in the subject edges, but we've ultimately proven quite graphically that it has nothing to do with the problem, which turns out to be a Photoshop bug / weirdity. 

                                                                         

                                                                        Why a perpective correction tool that can only have straight edges should be able to introduce curvature is beyond me, but Adobe moves in mysterious ways.  Perhaps logic is shared behind the scenes with the Warp function.

                                                                         

                                                                         

                                                                        A considerable amount of the logic at Adobe seems to be highly questionable. The biggest mystery is how we've got a Photoshop that runs at all.

                                                                        • 33. Re: Maybe a bug in prospective crop tool?
                                                                          Noel Carboni Community Member

                                                                          Here, I've created even better examples, using Photoshop's 3D facilities so the perspective distortions are mathematically perfect.

                                                                           

                                                                          Note how differently the Perspective Crop Tool performs on these two very similar looking planes.

                                                                           

                                                                          PerspectiveDistortedPlane1.png

                                                                           

                                                                          PerspectiveDistortedPlane2.png

                                                                           

                                                                          -Noel

                                                                          • 34. Re: Maybe a bug in prospective crop tool?
                                                                            conroy Community Member

                                                                            Photoshop gave me a correct result with your second image.

                                                                             

                                                                            However, here is the hilarious result for the first image:

                                                                             

                                                                            Screen-shot-2012-10-20-at-14.24.12.png

                                                                             

                                                                            Now the freeware (Windows software running in an emulator on my Mac). First the setup - see the useful little zoom boxes and numeric controls which show and can precisely adjust where I placed 4 corners on the image.

                                                                             

                                                                            Screen-shot-2012-10-20-at-14.22.57.png

                                                                             

                                                                            The result:

                                                                             

                                                                            Screen-shot-2012-10-20-at-14.23.48.png

                                                                            • 35. Re: Maybe a bug in prospective crop tool?
                                                                              Noel Carboni Community Member

                                                                              Yeah, that's the same result I got.

                                                                               

                                                                              Another thing your program demonstrates is the potential utility of not cropping to the edges of the plane, which could potentially be handled by the addition of a [  ] Delete Cropped Pixels checkbox in the perspective Crop Tool.

                                                                               

                                                                              -Noel

                                                                              • 36. Re: Maybe a bug in prospective crop tool?
                                                                                Hudechrome Community Member

                                                                                Noel Carboni wrote:

                                                                                 

                                                                                Hudechrome wrote:

                                                                                 

                                                                                There is a check box to not center. It makes no difference checked or unchecked.

                                                                                 

                                                                                Oh, geez, if that checkbox didn't work for me I'd surely be ranting.

                                                                                 

                                                                                Lawrence, try this:

                                                                                 

                                                                                1.  Open Photoshop and open exactly one image.

                                                                                2.  Choose the Crop Tool

                                                                                3.  Click the Gear icon and uncheck Auto Center Preview.

                                                                                4.  Close the document, and close Photoshop (gracefully).

                                                                                 

                                                                                Does it stick for future crops?

                                                                                 

                                                                                -Noel

                                                                                I cannot find an image called Exactly One, Noel. Where is it stored?

                                                                                 

                                                                                I have already done that. The check box is sticky (unchecked), the crop, centered.

                                                                                 

                                                                                Look, Crop has been on my rant list since day one, starting with the imposition of a centered crop and ending with the crop box sustained after the crop is finished. I've complained about it what, a year ago or whenever CS6 came out. Now, the box should only appear after I have actually created the crop, either with a fixed ratio or uncommitted. Is that too hard to understand? When you pick up a couple of cropping L's and place them on a print you have the immediate choice of where to start. This isn't the place for a tutorial on cropping so I won't go into it. Suffice it to say there is a logical place to start and it isn't in the center of a rectangle.

                                                                                 

                                                                                If you are cropping under the enlarger with an easel, now CS6 comes closer to what happens there but still, no comparison.

                                                                                 

                                                                                So, here's my recommendation to Adobe cropper writers: Engage the tool. Pick a format (4x5 etc) if desired. Have a blinking cursor allowing the placement of a corner. Draw the box.. Commit when satisfied. Show the finished image sans cropping rectangle. Make that Classic and give me that option along with whatever wisdom you folks wish you offer.

                                                                                 

                                                                                Maybe include a sample image called "Exactly One".

                                                                                • 37. Re: Maybe a bug in prospective crop tool?
                                                                                  Hudechrome Community Member

                                                                                  "Perhaps logic is shared behind the scenes with the Warp function."

                                                                                   

                                                                                  Gad! Tou mean Adobe has figured out Warp Drive?

                                                                                  • 38. Re: Maybe a bug in prospective crop tool?
                                                                                    Hudechrome Community Member

                                                                                    What freeware, conroy?

                                                                                    • 39. Re: Maybe a bug in prospective crop tool?
                                                                                      conroy Community Member

                                                                                      Hudechrome wrote:

                                                                                       

                                                                                      What freeware, conroy?

                                                                                       

                                                                                      Image Analyzer for Windows

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