Author Topic: Jasc Paint Shop Pro 9... cm vs. in (Read 19,218 times)

crabby3 · « **on:** March 28, 2012, 10:05 AM »

This is a continuation of another topic I started with a similar name...

...but this one has a more accurate header and content.

I use Mousers SC screencap program to grab pics and save them in the PNG format. But when I open them in PSP the Image Dimensions are in metric (milimeters, ppcm) instead of US Standard (inches, ppi).

Obviously this question is aimed at other users of this Great Classic Program and any related info on this issue would be appreciated!

BTW I have these installed too: PSP 9.01 Patch, PSP 9.0.1.1

Jibz · « **Reply #1 on:** March 28, 2012, 12:36 PM »

Related:

http://forum.corel.com/EN/viewtopic.php?f=56&t=43896

Looking at a screenshot saved from SSC, it appears to correctly set the pHYs chunk to 96 dpi, perhaps PSP fails to do the proper conversion when loading an image with the unit specifier flag set to meters?

mouser · « **Reply #2 on:** March 28, 2012, 01:06 PM »

Quote

perhaps PSP fails to do the proper conversion when loading an image with the unit specifier flag set to meters?

wait this is the key part -- are you saying that its possible for the png file to specify whether it is stored in meters?

this is the key part we have been struggling with. Jibz you sound like you are saying that the SC image says that the file should be viewed as using the "meters" unit. Is that so?

Jibz · « **Reply #3 on:** March 28, 2012, 02:01 PM »

Quote from: mouser on March 28, 2012, 01:06 PM

wait this is the key part -- are you saying that its possible for the png file to specify whether it is stored in meters?

Quote

4.2.4.2. pHYs Physical pixel dimensions

The pHYs chunk specifies the intended pixel size or aspect ratio for display of the image. It contains:

Pixels per unit, X axis: 4 bytes (unsigned integer)
Pixels per unit, Y axis: 4 bytes (unsigned integer)
Unit specifier: 1 byte

The following values are defined for the unit specifier:

0: unit is unknown
1: unit is the meter

When the unit specifier is 0, the pHYs chunk defines pixel aspect ratio only; the actual size of the pixels remains unspecified.

Conversion note: one inch is equal to exactly 0.0254 meters.

So, for PNG files, the pixels per unit are either for "meter" or "unknown". SSC sets the unit to meter (1) and pixels per unit to 3780x3780, which correctly converts to 96 dpi x 96 dpi.

Note that the only proper unit is meter here, there is no option to use inch, and the unknown unit seems to only be useful for specifying an aspect ratio.

crabby3 · « **Reply #4 on:** March 28, 2012, 02:08 PM »

Quote from: Jibz on March 28, 2012, 12:36 PM

Related:

http://forum.corel.com/EN/viewtopic.php?f=56&t=43896

Looking at a screenshot saved from SSC, it appears to correctly set the pHYs chunk to 96 dpi, perhaps PSP fails to do the proper conversion when loading an image with the unit specifier flag set to meters?

Thanks for your time, Jibz, but I'm not sure I understand your answer.

I entered unit specifier flag set to meters? into my browser and found this. I don't understand much of it... so it may not even apply here.

crabby3 · « **Reply #5 on:** March 28, 2012, 02:19 PM »

Quote from: mouser on March 28, 2012, 01:06 PM

Quote
perhaps PSP fails to do the proper conversion when loading an image with the unit specifier flag set to meters?

wait this is the key part -- are you saying that its possible for the png file to specify whether it is stored in meters?

this is the key part we have been struggling with. Jibz you sound like you are saying that the SC image says that the file should be viewed as using the "meters" unit. Is that so?

Thanks for your time too, Mouser, your reply sounds promising.

Jibz · « **Reply #6 on:** March 28, 2012, 02:32 PM »

Quote from: crabby3 on March 28, 2012, 02:08 PM

Thanks for your time, Jibz, but I'm not sure I understand your answer.

I think the gist of it is that the PNG file format stores the pixels per unit in pixels per meter, and that is probably why PSP shows it to you in metric instead of US units. It is not something specific to Screenshot Captor, it is in the PNG file format

.

I would expect if you save a PNG file from most other programs you would see the same when opening it in PSP.

Ath · « **Reply #7 on:** March 28, 2012, 02:50 PM »

Opening a .png file using Paint.NET gives me the units which are set (by default) in Paint.NET, and it knows how to convert the resolution stored in the .png. If I change a setting, like Image/Resize, to be pixels/cm instead of the default pixels/inch, the next time it has remembered my choice. I like that behavior.
Most likely because of the age of PSP, compared to the age of .png, it doesn't have all this 'sophistication', yet.

crabby3 · « **Reply #8 on:** March 29, 2012, 04:28 AM »

Quote from: Ath on March 28, 2012, 02:50 PM

Opening a .png file using Paint.NET gives me the units which are set (by default) in Paint.NET, and it knows how to convert the resolution stored in the .png. If I change a setting, like Image/Resize, to be pixels/cm instead of the default pixels/inch, the next time it has remembered my choice. I like that behavior.

Hi Ath... I have Paint.net but I don't use it much. IMO its main function is to alter or edit the entire image... not just specific areas in the image. (I guess that's why there's no point-to-point selection tool?)

It also seems to be more of a 'playground' for other user/programmers because there's a TON of plugins... and about 99% are effects.

Using PSP I can change a PNG image from ppcm to ppi too... and it remembers my setting... but only if I Save AS and change the format to anything but PNG. This is the extra step I was trying to avoid... and what started this topic...

There's a screencap function as well, but you have to launch PSP and keep it running, to use it.

That's why I fell in love with SC. Just click the icon and your ready to go!

crabby3 · « **Reply #9 on:** March 29, 2012, 12:26 PM »

Found a solution to this PNG-Metric-grabbing issue... and the problem doesn't seem to be related to my Paint Shop Pro.

Thanks to all... for your input!

tomos · « **Reply #10 on:** March 29, 2012, 01:37 PM »

Quote from: crabby3 on March 29, 2012, 12:26 PM

Found a solution to this PNG-Metric-grabbing issue... and the problem doesn't seem to be related to my Paint Shop Pro.

aren't you going to tell us what it is

- I could actually use a solution for that (I have had the problem of my Photoshop not being able to read size of image files (I think it was with pngs) - it just showed them at 72dpi.

crabby3 · « **Reply #11 on:** March 30, 2012, 02:12 AM »

Quote from: tomos on March 29, 2012, 01:37 PM

aren't you going to tell us what it is
- I could actually use a solution for that (I have had the problem of my Photoshop not being able to read size of image files (I think it was with pngs) - it just showed them at 72dpi.

The solution was meant to be vague... there didn't seem to be much interest in my this problem...

NOTE: Pay attention when you install or else you may get stuff you don't want!

The magic word is PicPick ... not Abrakadabra...

OS: 2000/XP/Vista/7

Not sure if this will cure your problem tomos. My problem was grabbing stuff (with SC) that Jasc Paint Shop Pro would open in Metric instead of US Standard.

If your Photoshop is already reading in inches... maybe you can adjust your default.

tomos · « **Reply #12 on:** March 30, 2012, 11:57 AM »

^ thanks Crabby, but my problem wasnt with screenshots at all (but *was* with PNG files.) Not important to me anyways as it's not a current problem for me.

Quote from: crabby3 on March 30, 2012, 02:12 AM

The solution was meant to be vague... there didn't seem to be much interest in my this problem...

Not sure where you get that from - you got lots of replies

(I've started threads that have gotten no replies lol)
We just thought (incorrectly) that the problem was with PSP, until Jibz pointed out above, the way that PNGs are either set to "no-units" or metric.

mouser · « **Reply #13 on:** March 30, 2012, 03:30 PM »

Crabby has sent me a png file that does in fact load up in PSP and show image info in inches (compared to SC png images which show info in centimeters)..
So clearly something in the png files are tagged differently.
I'm looking into it now.

mouser · « **Reply #14 on:** March 30, 2012, 03:50 PM »

After a quick look, it seems as though the png image that crabby has that shows info in inches in PSP is actually lacking any DPI info in it, making PSP use a default and not showing dpi. I think that's what's happening.

I think basically what's happening is the other program is not storing DPI info in the file.

Crabby perhaps you can confirm by simply saving this file from PSP as a different name, then closing the file and reopening it. Does it now show in millimeters or still in inches?

I wonder if it might be smart to add an option in SC that said basically "Don't store DPI info when saving files".. question is whether that would backfire.

crabby3 · « **Reply #15 on:** March 30, 2012, 05:28 PM »

Quote from: mouser on March 30, 2012, 03:50 PM

Crabby perhaps you can confirm by simply saving this file from PSP as a different name, then closing the file and reopening it. Does it now show in millimeters or still in inches?

It reverted back to Metric...

tomos · « **Reply #16 on:** March 30, 2012, 07:58 PM »

Quote from: mouser on March 30, 2012, 03:50 PM

After a quick look, it seems as though the png image that crabby has that shows info in inches in PSP is actually lacking any DPI info in it, making PSP use a default and not showing dpi. I think that's what's happening.

so the programme just desnt know the actual size of the image and is just guessing/using a default setting, say 96dpi, or 72dpi ?

FWIW, I realise now that my ancient Photoshop (5,5) does not recognise any dpi info in PNGs. Screenshots from mouser's SC - show at 96dpi in SC but at 72dpi in Photoshop...
If I change the dpi in SC it still doesnt change in Photoshop.

tomos · « **Reply #17 on:** March 30, 2012, 08:01 PM »

So, (the plot thickens?) -
I guess it could also be possible that PSP is just guessing the size - especially if it's in inches, but also even if shown in metric...

You could test it by opening PNGs with a different resolution/dpi to the standard that you're always seeing in PSP.

crabby3 · « **Reply #18 on:** March 31, 2012, 05:20 AM »

@Mouser

Would it be better/worse, easier/harder, to add PSP to Screenshot Captor's Default Image File Format?

This may fix this issue.

The PSP file size appears to be more than PNG but less than TIF. This comparison was made on the image I sent you. <(This is unrelated additional info)

-----------------

BTW....... There's a typo on the SC Image File Format page. Bottom paragraph, second sentence... transparency is spelled with a t at the end... transparenct

crabby3 · « **Reply #19 on:** April 01, 2012, 02:15 PM »

Hey Tomos... I just noticed your reply...

Quote from: tomos on March 30, 2012, 08:01 PM

So, (the plot thickens?) -
I guess it could also be possible that PSP is just guessing the size - especially if it's in inches, but also even if shown in metric...

You could test it by opening PNGs with a different resolution/dpi to the standard that you're always seeing in PSP.

In PSP there's a Units tab under General Program Preferences that I've never understood the purpose of. This is where: "The default resolution will be applied to any image or file without a resolution value." I thought all pics already had a resolution value.

It can be set from 1.000 to 2540.000 in ppi or ppcm. I have it set at 200.000 ppi. (I think the original default was 96.000 ppi. ...but it's not worth resetting all my other preferences to find out.)

To run the test... I reset the resolution to 201.000 ppi, opened a PNG, and it showed 201.000 ppi.

So I guess Mouser's conclusion is correct...

Quote from: mouser on March 30, 2012, 03:50 PM

I think basically what's happening is the other program is not storing DPI info in the file.

Please excuse the delayed reply.