Kodalith Effect

[Teamouse]

What is Kodalith

It is a Black and White image that is made by using Kodalith high contrast
black and white film. The image is pure white and pure black, there is no
shades of grey at all.

Here is the Original image I used

Original Size Ppi 180 at 20 inches

After - Script was applied at 128%

[Teamouse]

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[LeviFiction]

Thank you very much for sharing this script.

I've been having a lot of fun with it. Again, thank you.

[Teamouse]

...

[LeviFiction]

[Teamouse]

Nice!

[JoeB]

An interesting script and a nice effect, and thanks for posting. However, I find your instructions somewhat confusing for a couple of reasons.

First, PSP (and other graphic programs) do not have the ability to change the DPI of an image because DPI is solely a function of a printer and depends on the printer specifications. Graphic programs can only change the PPI (Pixels per Inch), which is simply embedding instructions into the image telling the printer how many pixels of the image to print per each inch of paper. The PPI setting of the image does not affect the size of the image as displayed on your monitor AS LONG AS you change the PPI setting without resampling (i.e., as long as you don't also take the step of deliberately altering the pixel size of the image). So the PPI of an image, by itself, will have no effect on any type processing done to the image. Resizing by resampling the image, however, regardless of the PPI, definitely will.

So that being said, are you saying that the original image that you posted (700px x 394px) is the actual image that you used and that you changed the PPI to 180 with resample checked and also set the print size to 20 inches (which would change the pixel size to 3600 x 2026 pixels), ran the script and then resized the image back to 700px by 394px?

[Teamouse]

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[JoeB]

The original photo, that I posted here, the French horn. was a 20 inch wide photo, with180 Ppi. I reduced the photo down so I could post it. Thats the size of Pixels per inch my camera takes, 180.
Thanks for pointing that out, the different in Dpi (Dots per inch) and Ppi (Pixels per inch). My mistake. I stand corrected, updated post.

Thanks for the clarification. However, I have to point out again that the information about PPI doesn't matter, because it doesn't have any affect on the processing of the image however that processing is done in an image editor. Pixel size is the relevant information. Can I assume then that you were actually referring to the fact that an image of high resolution (i.e., an image with quite large pixel dimensions) works better than one of lesser resolution?

I do want to experiment with the script you posted, and did make one attempt with the photo you originally posted. It did not, of course, provide as nice (as in smooth) an output as what you posted as your output image, but that was - I expect - also resized for posting.

So when time permits I will do more experiments with your script, because I like the B/W effect, although not sure that it can't be achieved with other available filters I might have. But that's also because - unlike LeviFiction - I don't have the knowledge to perhaps change some of the settings as the script progresses to fine tune the final output. But it's certainly a script that I can have some fun with.

Perhaps you, LeviFiction, or others might be able to provide some input as to whether or not a user should be changing some of the different settings as the script progresses that can make the output better suited to specific input images. Not a necessity, but just asking.

I should add that my few experiments this afternoon did indicate that the input image would provide a better output image if there was a reasonably average distribution of dark and light values throughout the image. In other words, images that didn't give great results were those with, perhaps, good image value distributions in the foreground (e.g., beach scenes with pebbles, nearby ocean scenes with dark waves with brighter highlights) but with clear skies or light clouds that just washed out into white. Both your and LeviFiction's images had lots of dark and light throughout the whole image, which worked out fine.

[hartpaul]

I also did an experiment on the same image using the script and also the Threshold adjustment. I found the results very similar but the threshold was a bit harsher. I obtained a closer result by first using Adjust > Brightness and Contrast > Brightness/contrast and first reducing the contrast a little which I suspect is what the other parts of the script do before applying a Threshold adjustment.

I found that I could change and see my results with better control using a Brightness/Contrast Adjustment layer and on top of that a Levels Adjustment layer and finally a Threshold Adjustment layer.
Then adjustments could be made to one or more layers and their effect seen in real time.

[Teamouse]

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[hartpaul]

I carried out some more tests again with the same dimensions 2000 pixels on the longest side. I changed the PPI without resampling so that the pixel dimensions remained the same to 10 , 72 and 300 PPI.
There appeared no difference in the images when viewed in quick succession in Irfanview. It is very difficult to see how a printing instruction - the number of pixels to print per inch of paper - PPI , can change processing .

[JoeB]

The reason I left the Script as is, because it will work on higher Ppi than 180, I would say that 180 is minim.

As @hartpaul says and, to repeat what I have said, the PPI of an image has absolutely no affect on the processing of an image. It cannot have any effect because it is simply instructions telling the printer how many pixels of the image to print per square inch of paper. The only way you could see any difference to the output using the same image but with different PPI settings would be if you are changing the PPI in PSP and also have Resample using... checked.

In those circumstances, once you change the PPI and hit OK the image pixel size will change. If you lower the PPI the image will become smaller in pixel dimensions because some pixels will be thrown away, and if you raise the PPI the image will become larger in pixel dimensions because pixels will have been added through interpolation. This decrease or increase in pixels changes the pixel composition of the image and therefore any operation on the image will have different results because the operation has a different pixel composition to work on. Simply changing the PPI of an image WITHOUT allowing the image to upsize or downsize in pixels does NOT change the pixel composition of the image, so regardless of PPI any operation on the image will have the same effect regardless of the PPI of that same image.

This does not make the script any less of a nice tool to use to get a nice effect. But it is important for users/readers to understand that it isn't the PPI of the image that might affect the quality or smoothness of the result, but only the image pixel composition. So the PPI information included with the post is irrelevant and its inclusion will likely only cause confusion for some readers.

And that said, I did get a much smoother result on the original image that was posted by actually upsizing the image substantially prior to using the script and then downsizing to the original 700 pixel image. This is not a surprise because it is well known that, when doing image manipulation that can produce sharp edges or other similar artifacts, it is often useful to upsize the image about 400%, do the manipulation and then downsize to the original to reduce the jagginess or artifacts that might be produced (i.e., to get a somewhat smoother result). It depends on the image, of course, and the final desired effect.

[JoeB]

@Teamouse,

I note that, just like in your Wall Art post, you have suddenly removed ALL of the information regarding this script and the Wall Art script you posted. So I'm copying (below) my last post in the Wall Art thread because I can only assume it was a result of my posts regarding the PPI info you provided:

I wasn't suggesting that you delete all of the information you provided about the script! Most of that was really useful and I think your script users - myself included - would appreciate it. All I was suggesting was that you don't bother adding information about using the script on images with any specific PPI setting, because that might make some users think that it was necessary to change that resolution. If there is a maximum or minimum or optimum pixel size that works best for the script then, of course, that's also good info to provide. It's just not helpful - and can be confusing - if information regarding print size (inches) and PPI is used to try to set parameters for the type of image that works best.

So I hope you didn't misunderstand my meaning or intent. There's no need to go from one extreme to another, eh? Or, to use another cliché, throw out the baby with the bathwater?