FF Killing Resolution

I just discovered why all my renders at high res are not coming out right... FF is converting all resolutions to 72 DPI while keeping the same pixel size...thus degrading the result resolution of any image higher than 72 DPI put through any filter... This one should definitely be at the top of FF's "Must Fix ASAP" list...

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StevieJ FF is converting all resolutions to 72 DPI while keeping the same pixel size

WOW! I did not know about this and I did not notice until you have said it, thanks for letting me know about this.

Although is true and surprising that Filter Forge really convert all the results to 72 DPI for all the results and I did not know that, BUT as it keeps the same pixel size it does NOT resamples the image, so there is no loss of quality, and so there is no degradation of quality, unless you print it at 72dpi

As ThreeDee have said, the simple solution is to "resize" (not really good word because you are not resizing it really) the dpi to the value you want WITHOUT resampling it, so you keep the same quality and can change the dpi as you want.

It can be done in Photoshop or any other similar software that allows to do this

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I have also seen that it has been discovered also by another one in this website

Jilbert´s website about Filter Forge

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Jilbert website Another little thing I discovered is that Filter Forge saves this “image” at 72dpi … if you are planning on using this for scrapbooking, you need to bring it into your favorite graphics program and save it back out at 300dpi. If you want to avoid this step, start from Photoshop; create a new document at 300 dpi; create a new layer; and start up Filter Forge from there (Filters > Filter Forge > ). That way you can insure the item is saved out at the right resolution.

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I have also seen that this topic has been already been in another thread before

DPI question

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jffe What's the deal with setting DPI in the FF stand-alone ? I cannot seem to find a place to do that, and I can't imagine that we're supposed to just do the pixel math, then convert it to 300DPI or whatever

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Vladimir Golovin wrote in february 2007 (I've added this to the list, but it's currently placed on low priority, so don't expect it soon. There are things with higher priority that need to be fixed in this department, for example color management. Personally, when I need to change the DPI while preserving the pixel dimensions, I use Photoshop's Image Size dialog with the Resample checkbox turned off.

He was right to not wait and expect it soon still in 2013 it has not been solved

BUT as he says there is the Photoshop Image size dialog OR there are also other FREE or alternative software that can also make the conversion without having to calculate anything.

I think I get what you mean! But allow me to explain this quickly before this becomes another confused thread.

Here's a small test I did with 72ppi vs 300ppi on a 1280x720 rendered via the Photoshop plugin.



Doesn't seem like there's much difference. Right because ppi doesn't affect image quality, it comes into play when you have devices set at that resolution. Pixels per inch is speaking about density of the pixels within a certain amount, in this case inches. Given that if you have an image set at 1280x720 at 300ppi, you basically have 300pixels crammed into 1inch of space on screen. Note that by changing ppi you're effectively targeting certain screen devices. But, it won't affect the number of pixels that image actually is.

PPI/DPI (while having different properties) often get shared a spot. For example a 900x900px image set at 300dpi becomes a 3x3inch image, but a 900x900px image set at 100dpi will be a 9x9inch image when printed. Note that the differences aren't in the image resolution but affects the size in print. Once again, just like with ppi dots per inch is telling the other device "cram more dots in 1 inch".

You can set ppi/dpi right in Photoshop without scaling the image of course. Just disable resampling and you're done. It won't affect what pixel size you have, it'll affect the density of pixels which get displayed when printed or observed on a separate device.

Pretty sure you already know this with all of the talk above!

I think preview resolution is the culprit here. When FF renders a 600x600 resolution for preview, it's really only doing as much. So if you render 10,000x10,000 px resolution, but you sample the image with a 600x600 preview, you'll more likely get a different result. This happens with other high-end render engines too! Preview render is often a bit ... distorted and a bit messed up. You'd have to compensate for anything of that nature.

In FilterForge, you can right click and view "actual pixels" in preview and see all the pixel glory. Remember, you can fix ppi later in Photoshop without affecting the pixel image resolution.

I think that keeps a lot of things covered, I think much of what I said there was right but you know... if there's something faulty I would like to know. SpaceRay's provided several little readings that totally answer your issue.

Hope that kinda... helps?

I still believe (although I haven't tried it) that you should be able to render a 10,000 x 10,000 pixel 72 ppi image and then convert it to 300 ppi afterwards.

THE 72 DPI/PPI LIMITATION OF FF CAN BE SOLVED IF USED AS A PLUGIN APPLYING TO THE IMAGE WITHOUT SAVING DIRECTLY FROM FF


I have made some tests and if use the standalone version it will always save the result as 72 pixels/inch BUT I have seen that if you use FF as a plugin and use the "APPLY" to the image instead of saving it from FF, then it keeps the SAME resolution and dpi/ppi as the original when applying the filter to the image and it does NOT convert it to 72dpi/ppi.

BUT if you use the FF plugin AND you want to save the image directly from the FF plugin instead of applying the filter to the original image in the plugin host, it STILL will convert it to 72 dpi/ppi the same as in standalone.

So the problem seems when FF itself saves the image, so avoid to do it

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ThreeDee I still believe (although I haven't tried it) that you should be able to render a 10,000 x 10,000 pixel 72 ppi image and then convert it to 300 ppi afterwards.

YES; you are right, and is true, I have tried it myself and you CAN SAFELY convert it to 300dpi from 72dpi as FF saves it because it keeps the same pixels resolution, BUT what Steviej is saying is NOT that this can´t be done, what he is saying is that lots of color information is lost when saving at 72dpi/ppi by FF

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StevieJ You loose all picture information beyond 72 ppi... For example, I discovered this by running a 10,000 x 10,000 pixel - 300 ppi image thru a simple filter...and the result came out totally different from what the pre-rendered display image showed the result was supposed to look like

Well, to see if this happens to me, I have made myself some tests with a 12000x9500 image using the watercolor by Kochubey filter.

FF WILL CONVERT ALSO ANY IMAGE TO sRGB COLOR SPACE INSTEAD OF KEEPING THE ORIGINAL WHEN SAVING DIRECTLY

So it will convert the image to 72dpi/ppi AND also will convert any image from another color space to sRGB and will not keep it.

For me the saved result from FF standalone version looks exactly the same as the one you can preview using View --> Preview Size --> Actual . I mean that for me all the colors are the same and it seems that there is no loss of quality. The result is converted to 72dpi/ppi

BUT then after I used the FF plugin version and using Photoshop I made 2 images from the filter, I saved one version directly from FF plugin and then after I clicked on "Apply" so the filter was applied to the image in the host software. The saved from FF was at 72 dpi/ppi, and the applied to host kept the 300dpi/ppi

WHAT I FOUND was a slighty change in colors between both versions, and I wondered why and discovered that the image that I applied the FF filter instead of saving kept the original color space and the one saved directly from FF has been converted without notice to sRGB!!!!

More information here

Why FF converts all the images to sRGB color space WITHOUT asking?

BE AWARE photographers that use Adobe RGB and printers that use CMYK!!

This is how it renders stripped of original picture info from 300 ppi to 72 ppi...

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If you run a 10,000 x 10,000 pixel @ 300 ppi image thru a filter and the comes out as 10,000 x 10,000 @ 72 ppi... you've lost about 75% of the original picture information

No, you haven't, UNLESS the information has been RESAMPLED, and per my test FF does not resample the image, it just changes the resolution. You have the exact same 10 000 x 10 000 pixels as in the original image.

Aye, probably do some more tests here as well.

But please make sure that resampling is disabled when changing 300 to 72.

Also can see it taking a full 10k x 10k @ 300 ppi...render it at 100% quality...then render the same image at 25% quality...

This source of this problem may also lie in HDRI mapping in surface results...

What?

StevieJ, I'm honestly confused... you might wanna give us a full list of what you're doing step by step.

Gotcha. I see differences as well. Steps seem a bit complicated to do it exactly, but I'll pick up a creative filter that renders fast next time. So while you were writing that, I was conducting a test as well of my own. Quite curious myself. I kinda doubted myself here. heh.

So I made an image 10,000x10,000px at first 300dpi, then applied "clouds" Photoshop filter and saved that as png. The resulting image is 300.5mb. Then I changed the dpi to 72 via image size menu without resampling. I saved that as a separate file. File results in 300.5mb as expected.

I created a very simple filter that feeds the image right into the height of a surface filter for this test part because you were speaking about surface filters previously.

I first fed the 72dpi then fed 300dpi images into that filter. Now, I unfortunately don't have much time rendering the entire 10k image so I thought I take a portion of the render by screen capping a render in the FF window with "Actual Pixels" displaying (not the preview resolution). Note that both of these images are zoomed up at 100% of the 10k image on the left hand corner.



Now obviously, I've done something quite differently from what you've done. So I'm holding back conclusions here. But based on this test alone, I observe no difference between the two images. I hope this helps part of the discussion.

With love!

[Edited several times] Clarified details.

Here is my 10K 72 vs. 300 dpi test render.

In fact, if I lay one on top of the other in difference blending mode, I get a fully black image. So there is absolutely no difference between the two.

Hello StevieJ, I am sorry to say that I do not understand what you are saying and I have made another test and I can´t see any difference, and I can´t see where the image is loosing quality or information.

What FF is doing is ONLY a conversion WITHOUT RESAMPLING of the image fr om 300ppi (or whatever that is different than 72ppi) to 72ppi, and then you can take it back to 300ppi in any software that can do this and you are not loosing any information or quality if you do not resample it.

PLEASE GIVE US STEP BY STEP INSTRUCTIONS TO REPRODUCE IT

I think that we will not find what you mean and have discovered IF we do not know what we have to look for and where have to to look and what really happens.

Please tell us step by step what we have to do to be able to reproduce and test what you mean and what exactly have to do and what we have to search for and what is the problem and wh ere to find it and so it will much more easier to help you and really discover what is happening.

Also tell us wich surface filter to use that will give the bad result that you are telling

Also if you want you could show another screenshots and write what you are seeing wrong on that screenshot versus what should be.

When you save the render result fr om FF, what format do you use, is it TIFF, Jpeg or what are you saving it with? If Jpeg are you using a high compression?

Please StevieJ, have you tried to make the same that you want to do using FF as plugin with any host supported software?

Because I have tested that if you use FF as a plugin it does NOT convert the image to 72ppi and does not change the color space, and does not have any problem that may be possible with the standalone version.

Does it happens the same mistery thing that you are telling IF you use FF as a plugin also?

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Skybase StevieJ, I'm honestly confused... you might wanna give us a full list of what you're doing step by step.

As Skybase say and also as I said above, if you want that the FF team or any of us in the forum can help you discover what is wrong and what is happening you have to tell us WHAT are you exactly doing so we the FF team and we can reproduce ourselves and see what really happens.

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StevieJ The images are originally at high res size...display shows what the render should look like...but doesn't render even close to display image... As you cut the resolution to the original high res image, the render gets closer to what the display image is showing...and the same thing happens as you cut precision...

I am sorry that I now I understand even less than before, and do not know what you mean.

When you mean "display shows" is this when you change the menu View --> Preview Size --> Actual that is wh ere you can see what the render should look like and what you are going to get for real?
And you mean that FF when you try to use File-->Save with that same image (using FF standalone I think) and then FF renders the result you are getting a different result than the one shown by the Preview Actual Size?

What do you mean with "if you cut the resolution to the original high res image" when you have said that the images originally are already at high resolution size? How do you cut the resolution to the original size? which one is the original high res image and wich one is the source resolution?

So do you mean that if you have a 10.000 x 10.000 image that is the original size, you cut or reduce the resolution to half of it, you are getting the renders better and closer to what Actual Size preview shows?

What do you mean when you say that you "cut precision" ? What precision? Precision of what?

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StevieJ I think a start would be for FF not to be affecting resolution at all...like all other graphics programs... All images should come out at the exact resolution as they get put through a filter...

FF is not affecting (at least in my version) in any way the resolution of the image at all if I understand resolution by the size of the image that it has and not the 72ppi that you said above. When you put a 3000x3000 pixels image through FF you will get exactly the same 3000x3000 when rendering the result so the image resolution is not affected or changed.

Another different thing is that the ppi is modified from whatever the image may have configured to the 72ppi that FF converts any image result ONLY IF you are using FF as standalone or saving with File -->Save in the plugin, because if you use FF as a plugin the ppi will NOT be changed or modified and will keep exactly the same as the original source

IMAGE RESOLUTION

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What is Resolution? Resolution is the term used to describe the number of dots, or pixels, used to display an image.Put into some very basic terms, resolution is the quality of the image. As the resolution goes up, the image becomes more clear. It becomes sharper, more defined, and more detailed as well.

Image resolution explained very much in Wikipedia

What Is Image Resolution? Why Does It Matter?

Although with the same resolution you can have different quality depending on the file format you are using and if you are using lossy compression as it happens in jpeg files that degrades the quality if the compression is high.

PRINT RESOLUTION

Another different thing is the print resolution that means the size at what you can print an image depending on the image resolution it has that is measured in ppi (pixels per inch) and usually is 200 or 300ppi but for the web is used 72 ppi. BUT the ppi never affects or modifies the quality of the image what is important is the image resolution and if the image has some compression.

There this useful and interesting 7 pages PDF that explains it well Understanding Resolution and the meaning of DPI, PPI, SPI, & LPI

To know if the guilty is really Filter Forge (FF) that as you say, is "killing" the resolution

Please can you be so kind to do the following to make the test and see if this is true?

StevieJ, can you do a test any image that you may want using FF as a plugin of any host software that may be compatible with FF?

And using the plugin, just "APPLY" the filter to the image instead of saving it from filter forge.

Because I have seen that if you use FF as a plugin:

It does NOT convert the original ppi to 72ppi

It does NOT convert the original color space to sRGB

It does NOT change anything in the image (so it can´t "kill" the resolution) and only exports the filter render result to the host software without changing the original source metadata.

So if you make this test and then the result is really what you want and as you wanted, then you can really know that the guilty is the standalone version of FF

If after making this test you continue having the same problems even when you FF as a plugin, then there is another mistery and unknown problem that should be found and see what is and what happens

Statement above can use clarification: From wikipedia on PPI "Pixels per centimeter (ppcm), Pixels per inch (PPI) or pixel density is a measurement of the resolution of devices in various contexts: typically computer displays, image scanners, and digital camera image sensors."

PPI is important when handling computer monitor resolutions. Data set is the same, but what gets displayed is what's concerned: i.e. iPhone 5 has a monitor ppi resolution of: 326 ppi.

Update: I understand pixel density...which still is a change in resolution at the same canvas size... It looses pixel info any way you look at it...

I have also narrowed part of the problem down to a difference in HDRI dispersement between the low and high pixel "densities" of images... Take a look at the first sample pics of the same image that I posted... That would explain the fact that the display image resolution/density showing the result correctly with the actual high res image coming out much different... In other words...the HDRI is coverage id being posterized at high resolution...and why the smaller you go with the resolution/density...the more closely it matches the display result image... Does this make any sense???

This discussion deserves a bump because the phenomenon is a real time consumer. Standalone FF does render images at a document resolution of 72 PPI. It doesn't make sense for a user to have to post-edit every rendered image in a graphics program to change the rendered image back to the original resolution or use Filter Forge only as a plug-in to avoid the problem. I hope this is fixed in the foreseeable future.

It seems that it is still happening these problems that FF standalone will change
any dpi you may have to 72dpi
Will change any color profile to sRGB

But the good news is that as told above this does not happen if you use FF as plug in because it only applies the filter to the image but DOES NOT SAVE IT, so this is why it does not change the image to 72dpi and sRGB IF you use FF as plugin