14 Replies Latest reply on Aug 9, 2009 8:38 AM by Mike Ornellas

    Automatically select best resampling method

    Scott Falkner Level 5

      The three most common choices for resampling when changing resolution are:

      • Bicubic (best for smooth gradients)
      • Bicubic Smoother (best for enlargment)
      • Bicubic Sharper (best for reduction)

       

      Photoshop should be smart enough to know when I enter the new size whether it's larger or smaller than the original size, then select the appropriate method; Bicubic Smoother or Bicubic Sharper. This automatic selection can be a preference.

        • 1. Re: Automatically select best resampling method
          Reynolds (Mark) Level 4

          Apparently its not that smple - Bicubic Sharper isn't ALWAYS the best for downsamping, and Smoother isn't always the best for upsampling.

          • 2. Re: Automatically select best resampling method
            Scott Falkner Level 5

            Not relevant. A preference to select the appropriate one is all I'm proposing. The preference can be turned off or the user can change the resampling method after setting the resize amount but before clicking OK.

            • 3. Re: Automatically select best resampling method
              Mike Ornellas Level 3

              If its a preference, I see no point in it. It does not make Photoshop smarter nor the person using it. It just makes more inconsistencies in the app between multiple users.  I understand your point and desire to streamline logical choices, but its irrelevant in the big picture of things.

              • 4. Re: Automatically select best resampling method
                Reynolds (Mark) Level 4
                A preference to select the appropriate one is all I'm proposing

                Thats the problem, no-one knows whats likely to be 'appropriate'. Same as life… sigh

                • 5. Re: Automatically select best resampling method
                  Scott Falkner Level 5

                  Incorrect. The preference would tell Photoshop to select Bicubic Sharper when making the image smaller or Bicubic Smoother when making the image larger. That's it.

                  • 6. Re: Automatically select best resampling method
                    Mike Ornellas Level 3

                    Scott -

                     

                    The problem is BEING a preference.

                    • 7. Re: Automatically select best resampling method
                      Scott Falkner Level 5

                      What do you mean by that?

                      • 8. Re: Automatically select best resampling method
                        Mike Ornellas Level 3

                        Photoshop should be smart enough to know when I enter the new size
                        whether it's larger or smaller than the original size, then select the
                        appropriate method; Bicubic Smoother or Bicubic Sharper. This automatic
                        selection can be a preference.

                        You assume that all images are created equal in the sense of quality. What happens if you have lets say 20 images that you got from someone and they have all been hammered by various levels of users  - as they all came from various sources. ie scanner, camera, web, video, etc... Some of the images may or may not need sharpening when going up or down in interpolation.

                         


                        Putting a preference to control the behavior of resolution could lead to more damage then help if you look at things from a case by case basis.

                         


                        I actually like your idea Scott, but the way Photoshop is currently developed, it would just make more of a mess for the majority of users...

                         


                        IMHO - if there is such a thing...

                        • 9. Re: Automatically select best resampling method
                          Scott Falkner Level 5

                          Mike Ornellas wrote:

                           

                          You assume that all images are created equal in the sense of quality.

                           

                          I assume that the user would appreciate having Photoshop select one resampling method or another depending on the scaling applied. The preference can be turned off (even ship with the preference off).

                           

                          What happens if you have lets say 20 images that you got from someone and they have all been hammered by various levels of users  - as they all came from various sources. ie scanner, camera, web, video, etc... Some of the images may or may not need sharpening when going up or down in interpolation.

                          The user can override the choice after entering the new size or turn the preference off. A recorded action would also record the resampling method used when the action was recorded, which may not be Sharper for downsampling or Smoother for upsampling.

                           

                          Putting a preference to control the behavior of resolution could lead to more damage then help if you look at things from a case by case basis.

                          The preference does not "control the behaviour of resolution", it merely saves the user the trouble of selecting Bicubic Sharper or Bicubic Smoother before clicking OK. The user has the option to change that setting at any time.

                          I actually like your idea Scott, but the way Photoshop is currently developed, it would just make more of a mess for the majority of users...

                          If the preference to preselect resampling method is off by default, most users will remain ignorant of it or likely choose to leave it off. Those educated enough to appreciate it's value will turn it on and, in most cases, trust that the program is now selecting the optimal resampling method (even if it is not). Occasionally the program will not pick the optimal resampling option, and the user will not correct this. But in most of those cases, the user would likely have left the setting alone (Bicubic), or chosen the same setting anyway ("Let's see, I'm making it smaller, so I'll use the setting that's recommended for downsampling.").

                           

                          Professionals will either leave it off or turn it on to suit themselves, but still trust their judgement over the program's. So the majority of user will be either unaffected by the preference or will find a little time is saved. The real savings is not having to reach for my mouse.

                           

                          I don't know what you mean by "the way Photoshop is developed".

                          • 10. Re: Automatically select best resampling method
                            Mike Ornellas Level 3

                            All well thought out logical reasons Scott, and I would tend to agree with your observations and conclusions, but before I make this thread go sideways,  - I think a major question needs to be answered and that is...

                             


                            Is Photoshop intelligent enough to "think" or be able to "be aware".

                             

                            At some point softwares do acquire paths or means to apply best practice, but can an application obtain "sharpening logic" id?

                             

                            Something like scan recognition OSR's, but thats way out there at this point.

                             

                            If the application is currently capable of resolution recognition upon open, it may be done if the file formats support it - from the best of my knowledge - not sure if its even a consideration, - but that's an engineer question.

                             

                            As of now, Photoshop files "Understand" or "Track" file formats upon open as well as file extension names.

                             


                            - not sure about resolution info....

                             


                            anyone here know?

                             

                             


                            If YES - then we can go into ping pong mode for features requests and best practice, but for sure viability studies....;o)

                             


                            If NO - then you have your answer.

                             

                             

                            and the question about how Photoshop is being developed is more of an actual real world pet peeve list - about smart or dumb software issues

                            • 11. Re: Automatically select best resampling method
                              Scott Falkner Level 5

                              I'm not asking for AI or HAL-like thinking. All Photoshop needs to do is see if the numbers I enter in Image Size cause the image to be resampled and, if so, whther that resampling will enlarge or reduce the image. That's all the "thinking" required. If X>Y select Bicubic Smoother. If X<Y select Bicubic Sharper. End of story.

                               

                              If Photoshop tells me the AE 35 is going to go offline, then I'll worry.

                              • 12. Re: Automatically select best resampling method
                                Mike Ornellas Level 3

                                Some things that seem so simple are not so simple.

                                • 13. Re: Automatically select best resampling method
                                  Reynolds (Mark) Level 4

                                  Scott you seem to be under the mistaken impression that Sharper is USUALLY better for downsampling, and Smoother for upsampling. This is not the case. As I said in Post 1. In detail then:

                                   

                                   

                                  SHARPER: Look at the results, and analyse them for yourself. Take an image and take it down to a very small 500px using the different methods. You will see halo's in the sharper method similar to unsharp or high pass halos. Generally downsampling is best left to its default Bicubic, UNLESS you are going very small, where areas of very fine detail will be better preserved. Sharpening is best controlled with a definable radius.

                                   

                                  SMOOTHER: For upsampling 'smoother' was introduced to compete with fairly unscrupulous apps like Genuine Fractals, which claimed to do the impossible. Differences in results are extremely negligible, and Smoother creates a less sharp result. In some cases were very small source files are concerned, Bicubic Sharper is actually better for upsampling.

                                   

                                  Both of the alternate Bicubic methods, are MORE damaging than good old straight Bicubic- which was itself improved, and does an amazing job.

                                   

                                   

                                  Encouraging people to set the preference, in what is honestly a not very smart and very slightly damaging way is probably not a good idea.

                                  • 14. Re: Automatically select best resampling method
                                    Mike Ornellas Level 3

                                    To compound the issue -

                                     

                                    Scott - then do you want a preference to control Image Size differently over Transformations?

                                     

                                    Things start to get blurred if we keep compounding compounding complexities, but at this point the software is out of control so maybe who cares at this point.