lindarobin Posted February 27, 2016 Share Posted February 27, 2016 The thread "Removing an object from a photo" segued into the topic of resolution and print quality, so I am starting this new thread to continue the discussion. Often, we add a low resolution photo to a 12x12 300 dpi layout. When we enlarge the photo to fill the layout, the dpi of that photo usually falls below 300. That's why the photo looks fuzzy compared to the high resolution scrapbook graphics next to them. To enlarge the photo, PSE uses a technology called bicubic smoothing to add interpolated pixels. As a comparison, I enlarged a picture using PSE, then enlarged the same picture using MS Paint so the difference can be seen. Bicubic smoothing vs no bicubic smoothing. (These results can be replicated by anyone with both PSE and MS Paint.) The bicubic smoothing is a little blurry, but still much better than the jagged edges when no bicubic smoothing is applied. Later this week, I will try out my new program which uses "S-Spline" to add interpolated pixels. My expectation is that it will look sharper, but not jagged. Link to comment Share on other sites More sharing options...
Lesann Posted February 27, 2016 Share Posted February 27, 2016 S-Spline sounds interesting. Can't wait to hear your report. Who makes it? Hugs L Link to comment Share on other sites More sharing options...
lindarobin Posted February 27, 2016 Author Share Posted February 27, 2016 The program is PhotoZoom Classic 6 by BenVista. Link to comment Share on other sites More sharing options...
lindarobin Posted February 27, 2016 Author Share Posted February 27, 2016 I did it! The results of S-Spline are quite exciting. If you want to play along, open Penguins.jpg found in the Sample Pictures folder (Windows PC). Try enlarging it 250% in different programs and compare how well each program adds interpolated pixels. There are different algorithms to create interpolated pixels, some more sophisticated than others. Here are some of my results: Link to comment Share on other sites More sharing options...
terriscrapper Posted February 27, 2016 Share Posted February 27, 2016 I did it! The results of S-Spline are quite exciting. If you want to play along, open Penguins.jpg found in the Sample Pictures folder (Windows PC). Try enlarging it 250% in different programs and compare how well each program adds interpolated pixels. There are different algorithms to create interpolated pixels, some more sophisticated than others. Here are some of my results: Wow! Where is the folder with the penguins? I use a Mac is it compatible with yours? I wanted to follow along Link to comment Share on other sites More sharing options...
MariJ Posted February 27, 2016 Share Posted February 27, 2016 This is amazing, Linda! I'm off to bed now but your info is fascinating and I'm going to read it more closely tomorrow. Thanks so much for taking the time to post all this, it's something I've never quite understood. Link to comment Share on other sites More sharing options...
lindarobin Posted February 27, 2016 Author Share Posted February 27, 2016 I don't know what Mac includes as sample photos. Windows provides a folder of sample photos that can be used as screen savers/ wallpapers You can use any screen saver or desktop wallpaper image, to play with. Simply open that image in various programs that have a resizing feature. Enlarge to 250% and compare the results between your different programs. You can email me the image you experiment with and I'll "S-Spline" it and we can see how it looks against an enlargement made in PSE. Link to comment Share on other sites More sharing options...
lindarobin Posted February 27, 2016 Author Share Posted February 27, 2016 You're welcome MariJ. I've been reading internet articles found by googling S-Spline. It seems to be what some professional printing services use to make poster size prints from customers' digital camera files. I would love to try taking my 3600x3600 layout up to 7200x7200, so a 2 feet by 2 feet poster. Too expensive to actually get printed, but I could try to post a cropped screen capture here. Link to comment Share on other sites More sharing options...
terriscrapper Posted February 27, 2016 Share Posted February 27, 2016 I don't know what Mac includes as sample photos. Windows provides a folder of sample photos that can be used as screen savers/ wallpapers You can use any screen saver or desktop wallpaper image, to play with. Simply open that image in various programs that have a resizing feature. Enlarge to 250% and compare the results between your different programs. You can email me the image you experiment with and I'll "S-Spline" it and we can see how it looks against an enlargement made in PSE. Sounds good...I'll try to do something in the morning!!! Link to comment Share on other sites More sharing options...
Smiles Posted February 27, 2016 Share Posted February 27, 2016 Thanks so much, Linda! Your posts are always so informative. I sometimes do file-place to put a lower resolution object into a 300 dpi document. How would you say that compares to these methods? Link to comment Share on other sites More sharing options...
Boatlady Posted February 27, 2016 Share Posted February 27, 2016 Wow That is amazing.Thank you so much for that truely helpful information. Link to comment Share on other sites More sharing options...
lindarobin Posted February 28, 2016 Author Share Posted February 28, 2016 Thanks so much, Linda! Your posts are always so informative. I sometimes do file-place to put a lower resolution object into a 300 dpi document. How would you say that compares to these methods? Creating a Smart Object allows you to edit (e.g. rotating, skewing) the image and maintain the original image quality. For non-Smart Objects, these kinds of transformations result in some loss of quality for every edit made. However, scaling Smart Objects larger than their original size will still result in pixelation and loss of quality. When scaling images larger than their original size, that is to say you are adding interpolated pixels, the loss of quality can be affected by the algorithm that creates the interpolated pixels. PSE uses an algorithm called bicubic smoothing. It is generally considered pretty good at creating a larger resampled image. Other rescaling algorithms include nearest neighbour, bilinear, Mitchell, and Bell interpolations. I couldn't begin to explain the complex math behind these. It would be like explaining the mathematics of the different blend modes. As a non-professional, I just try a few and decide which result I like best. My new program provides me with several rescaling algorithms. "S-Spline" interpolation appears to be the stand-out. So far in my experimentation, it gives me the best results. (I will post some examples later.) It is important to remember that whenever you plan to print a photo really big, like 12" x 12", ideally you should capture the photo with a good camera with the resolution setting at 3600 x 3600 pixels or larger. The photography enthusiastics out there, with their Canon Rebels, can attest to this. Then there is no need to apply rescaling; no need to add interpolated pixels. Link to comment Share on other sites More sharing options...
lindarobin Posted February 28, 2016 Author Share Posted February 28, 2016 To demonstrate the capabilities of S-Spline interpolation vs bicubic smoothing interpolation, I'll use a scrapgirls embellishment, from SNU JeweledFlora collection. Here is a screen snip of the embellishment at its original size. I will enlarge this by 250% which requires adding interpolated pixels. Here are three different methods that add interpolated pixels. 1. Nearest Neighbor (this is what MS Paint can do) 2. Bicubic Smoothing (this is what PSE can do) 3. S-Spline (this is what PhotoZoom Classic 6 can do) Link to comment Share on other sites More sharing options...
Smiles Posted February 29, 2016 Share Posted February 29, 2016 Thanks for the thorough explanation, Linda! Link to comment Share on other sites More sharing options...
MariJ Posted February 29, 2016 Share Posted February 29, 2016 Wow, this is truly amazing and I can see the differences so clearly through your screenshots, Linda! Your new program looks great and this is all such helpful and fascinating information. THANKS so much for posting and taking the time to explain all this so well. Link to comment Share on other sites More sharing options...
lindarobin Posted February 29, 2016 Author Share Posted February 29, 2016 Thanks, Gayle and MariJ! One thing that is true for all rescaling algorithms - you have to start with a print quality photo. Rescaling does not fix photos flaws. It enlarges them! If a photo is just web size (fits only within the screen) or if the photo was taken with a poor quality lens, then it doesn't really matter which algorithm is used. Poor results across the board. In a scenario where I want to take a photo of a family reunion and print it to fit a 11x14 frame, I would use a good 16MP camera. But since I only have a 7MP camera, I would take the picture and apply rescaling using S-Spline. (In actual fact, I would take pictures of left, middle and right portions of the group, then stitch the photos together in PSE!) However, if presented with only one photo, then rescaling is the only option. Link to comment Share on other sites More sharing options...
MariJ Posted February 29, 2016 Share Posted February 29, 2016 Thanks, Gayle and MariJ! One thing that is true for all rescaling algorithms - you have to start with a print quality photo. Rescaling does not fix photos flaws. It enlarges them! If a photo is just web size (fits only within the screen) or if the photo was taken with a poor quality lens, then it doesn't really matter which algorithm is used. Poor results across the board. In a scenario where I want to take a photo of a family reunion and print it to fit a 11x14 frame, I would use a good 16MP camera. But since I only have a 7MP camera, I would take the picture and apply rescaling using S-Spline. (In actual fact, I would take pictures of left, middle and right portions of the group, then stitch the photos together in PSE!) However, if presented with only one photo, then rescaling is the only option. Even more cool info Linda - thanks again! And, while it's nice that so many people record events these days, not many understand that phone photos just don't hold up well when trying to use them in a project. I am always having trouble with those kinds of pics send to me, so your rescaling is fascinating. I love that idea of three pics stitched together, too. I'm off to check out if I have that feature in PSE. Who knew? Link to comment Share on other sites More sharing options...
terriscrapper Posted March 1, 2016 Share Posted March 1, 2016 Thanks, Gayle and MariJ! One thing that is true for all rescaling algorithms - you have to start with a print quality photo. Rescaling does not fix photos flaws. It enlarges them! If a photo is just web size (fits only within the screen) or if the photo was taken with a poor quality lens, then it doesn't really matter which algorithm is used. Poor results across the board. In a scenario where I want to take a photo of a family reunion and print it to fit a 11x14 frame, I would use a good 16MP camera. But since I only have a 7MP camera, I would take the picture and apply rescaling using S-Spline. (In actual fact, I would take pictures of left, middle and right portions of the group, then stitch the photos together in PSE!) However, if presented with only one photo, then rescaling is the only option. Wow! Great info!! I've sure learned a lot!! Link to comment Share on other sites More sharing options...
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