Resizing in X3... bad.

[nkzz]

I use PI to produce images for web site design (using since v4) and recently upgraded from version 10 to X3. Version 10 produces nice results when resizing digital photos down to something like 200 or 300 or 400 px in width... but X3 yields totally unsatisfactory results, with bad jaggies appearing along edges. It looks like its not anti-aliasing like PI has in the past. One thing I notice is that the new feature, "Resample for email", which reduces the image to 1024 px in width, does, in fact, perform a nice job resizing... with good anti-aliasing along edges... and from that point, I get good results when I resize further. What exactly is the purpose of "Resample for email" (other than to do what the broken resizing tool can't)? And... why does X3 do such a poor job resizing? And... how can one achieve satisfactory resizing if the target size happens to be larger than the 1024 you get from "Resample for email"? And... is there going to be a fix for this problem?

[heinz-oz]

I don't see where there is a problem. I resize with X3 and haven't noticed any deterioration since PI 10, 11 and 12.

What are your preference settings? Do you use Bilinear or Bicubic re sampling?

You can also change your preferred size for "Resize for email" in preferences from the default 1024 wide.

[nkzz]

Interesting. I never touched those settings.... and the defaults were Generation Quality: Bilinear... and Resample Method: Bicubic. Changing Resample Method from Bicubic to Bilinear made no difference. Changing Generation Quality from Bilinear to Bicubic made a big difference. The resized image is now much smoother, better anti-aliasing, and less of the granularity that had been showing up in areas with a basic even-colored background. So that fixed it. I loaded up PI 10 to see how that had been set during several years of use... Resample Method was Bicubic... but Generation Quality has different choices... Best, Good, Fair... and had been set to Best. Now that you've solved my issue (Thanks!) can you explain what this is all about? Besides what I have observed here, is there a reason to fiddle with these settings? Will the change that I made negatively impact other things?

[heinz-oz]

I guess one part of your question you have answered yoursel. Does it make much sense to fiddle with these things. It obviously does. Will the change you made impact something else, I honestly don't know, you'll have to be the judge of that.

I also cannot explain in detail what the difference is between bilinear and bicubic except that it does make a difference on some images, not on all. Changes are that, one day, you encounter an image where you again don't like the quality after resizing. My advice is this, change your resampling/regeneration settings to the other one and see.

[sjj1805]

... Will the change that I made negatively impact other things?

Of course it will
Corel have no idea what YOU are going to do with the software but whatever it is it will be different to what SOMEONE ELSE is going to use it for. Therefore Corel can only create a setting that might appeal to the majority of users but not all. In fact one day you might need to use THIS setting but on another day with another project you might need to use THAT setting.

I do a lot of video editing. For this hobby one of the most important settings is FIELD ORDER. Stuff from a Digital camcorder is in Lower Field first. Stuff from a TV card is upper field first. How on earth could Corel know if I am going to use a TV card or a camcorder? In fact I use both and so regularly have to change the field order settings.

This is the same as your problem with your bilinear and bicubic settings.

[nkzz]

In PI versions 4 through 10, I never had to pay attention to this, but I guess now I'll have to keep an eye on this one. Thanks for the input.

[heinz-oz]

Pi version 4 surely did not have to deal with 10 MP images or images from a mobile phone. PI X3 surely does and, if it is set up accordingly, does make a good job of it also. There is no one fits all settings. That is the beauty of it, you can make it do what you want, not what some programmer had in mind.

[darbs]

This is how I do same!
[1] Duplicate the photo = Ctrl+D

[2] Check that your sizes do show pixels = Left Click on the "Ruler" as shown on the bottom right-hand corner of the PI X3 program page and select "Pixel"

[3] Go to = Toolbar = Adjust = Resize = [Note the size of your photo as shown in "Document Size" boxes

[4] In = Resolutions - [dropdown arrow] - change it from - "User defined" - to "Display" = and within the same "Resize" box = "Document size" = change down to you previous photo size which you have noted from in instruction [3]
NOTE! - By only using "Display" without modifying its size your image will shown to about double its size?]

[5] Check and if required save the image from a "UFO" to a JPEG/JPG/JPE [JPEG file interchange format]

[heinz-oz]

Darbs, that way you will not resize the image at all. It will change the size if it is printed only. Never, ever, resize your image for printing. Changing the dpi will take care of that. Your printer will do that automatically when you tell it to print to a certain size paper.

Not only do you not resize your image in this way, by saving it as a jpeg again, you will apply the compression again, losing quality.

It is a bit more complex than that to physically resize an image to a different pixel size.

Some images look better with bilinear re-sampling others look better with bicubic. There is another one called Nearest Neighbor which really shouldn't be there anymore these days.

You can only resize your image by reducing/increasing the number of pixels along each side and re-sampling. Whether you do that in pixels or cms or inches is irrelevant in this context. Pixels, however, are the only meaningful measurement for an image in electronic form. It doesn't matter at all which dpi setting you use in resolution, on the screen, your image will stay the same size unless you reduce the pixel count.