Hi Alfred,

Oh come on now, you're going crazy! PNG's don't change by themselves by uploading to a server! :-p

Pleeeeeze d-load the CPT in my post at  Fri, Jul 18 2008 15:33.

1. Load the CPT. It's pure, we can agree.

2. Export as Tiff with transparency. keep CPT open. Note: when viewing a transparent tiff in a quick viewer (like my old ver of ACDSEE, or Irfanview) it may not show the transparency. You'll only see a solid block of color. but the alpha channel is in the file.

3. Export from PP as a transp. PNG anyway you like.

4. import your best PNG and the tiff into Draw, place over a black and you'll see. Same thing when brought into other progs. blech.

Alfred:

There is something else going on here, my original test file which is sitting here on my desktop works perfect, I can load it in PP a hundred times, place a black background behind and it looks good. Now the uploaded test file looks like your examples after I download the file from my server, there is something going on between the original file and the uploaded version, however the only thing I did to it was upload it to the server.

Well I don't know, have to play with it some more!

OK, so I'm a little loco :) But why is the original, I made yesterday, still working perfect while the uploaded version of the original does not? Tell me? Tell me now? :)

Harrrrrrrrrrr, loco Alfredo.  

FosterCoburn:

Alfred,

I've never run into the problem either and rarely does a day go by when I
don't have a transparent PNG to create.

Thanks Foster, that post does give me some indication that I'm not totally cookoo yet :)

OK, email your "good PNG" to me then for inspection, or attach here to forum. It might not look right in the forum depending on browser, you know what I mean.

Jeff

Alfred:

OK, so I'm a little loco :) But why is the original, I made yesterday, still working perfect while the uploaded version of the original does not? Tell me? Tell me now? :)

Harrrrrrrrrrr, loco Alfredo.  

I will send you the file later on this week, I'm quite busy for the next few days, not much time for play! 

I've looked into this before: the problem is that PPaint does merge the image before applying the mask...

PP treats transparencies very poorly: once a pixel has a level of transparency applied to it, then you can only make it more transparent. The transparency is not a non-destructive lens {which it should be IMHO}. If you want "proper" PNG's with proper alpha channel masks within PP, then you have to maintain the original object at 100% opacity (or at least have it look this way at time of export) and use the mask as a proper alpha channel. (I would duplicate the object, hide the original, get the transparency you want, then create a mask from the object, show the origional and then export.)
(PShop I presume works with transparencies as a separate "lens" or whatever the equivalent is - therefore no problems.)

Since the object's transparency is "locked", PP flattens the image, then applies the transparency to the flattened image. So you get a whiteness - the transparency is almost applied twice. On import of a PNG, PP applies the transparency to the object so you now loose the origional object's pixel data - save it out as a PNG and you have the same problem, except no "origional" that you can have at 100% opaque to generate the correct output.

Draw works differently: each transparency is editable (and removable) once applied - when exporting, it takes all the transparencys and makes an alpha mask from them. Then ignores all opacity data and exports a flat image with the correct alpha mask. So you get a "proper" PNG file without any hassle.

{I don't "Know" this as fact: I am deducing this from what's happening.}

Gadget:

I've looked into this before: the problem is that PPaint does merge the image before applying the mask...

Yep, it's a bug...

Gadget:

PP treats transparencies very poorly: once a pixel has a level of transparency applied to it, then you can only make it more transparent. The transparency is not a non-destructive lens {which it should be IMHO}.

I like that it's permanently applied for most of my work... :-D    You could use a clip mask for non-destructive purposes.

Gadget:

(PShop I presume works with transparencies as a separate "lens" or whatever the equivalent is - therefore no problems.)

Not sure about that...

bottom line.. a tiff comes out of PP correctly.

I tried a clip mask... still bad result. I tried saving an alpha channel. bad yet again.

New idea:  I saved a PSD from PP with a semi-transp. object.

opened back into PP, looks as expected. Saved as PNG, no good.

Same original PSD opened in PS. made a PNG, it is good from PS.

If there is a direct way, it doesn't look easy.

Here's a method that works for me that involves using Paint.NET a freeware lite-weight paint program.

First export selected graphic object to TIFF (check "Selected Only" box; shoud work directly from CorelDraw or PhotoPaint). 

Open TIFF file in Paint.NET.

Save as PNG.

Paint.Net seems to do all the ugly behind-the-scenes stuff for you (and good if you don't have Adobe Photoshop)

http://www.getpaint.net/download.html

Never seen a issue with PNG myself, not that I don't trust you all to be right.

But watch out for IE it's support of PNG is flaky as.

Gadget:

PP treats transparencies very poorly: once a pixel has a level of transparency applied to it, then you can only make it more transparent. The transparency is not a non-destructive lens {which it should be IMHO}

Gadget:

PP flattens the image, then applies the transparency to the flattened image. So you get a whiteness - the transparency is almost applied twice.

In my previous post, the second rectangle is actually two rectangles; I combined the above with a third white duplicate, loaded a mask from an alpha channel I created from the rectangles and exported to PNG with 'Masked Area' selected (image attached).

Yeah you can tell it automatically sets the background to white when exporting or saving to PNG because the original and preview have the white background in the dialog box (instead of the checkered invisible background.)

If you fool around with the settings and make white the invisible color it seems to only change the pure white pixels to transparent but the image's pixels are still alpha blended with the white background.

I imagine the PNG format is "old-school" where back in the day you had to make your icons or toolbar images with a magenta background and program the settings to make magenta the invisible color. That is to say their color mode is RGB with a specific color used as the transparent color. 

Corel doesn't do it right, but a other programs like Paint.NET make the PNG work perfect. It handles all the ugly settings in the background.

That is one big shortcoming with Corel is that they don't have an ARBG color mode, which is surprising considering Microsoft has used it for the last 5 years since Windows XP (and GDI+) came out. 

CountZero1942:

I imagine the PNG format is "old-school" where back in the day you had to make your icons or toolbar images with a magenta background and program the settings to make magenta the invisible color. That is to say their color mode is RGB with a specific color used as the transparent color. 

I think PNG has supported an 8 bit alpha since the beginning.

CountZero1942:

Corel doesn't do it right, but a other programs like Paint.NET make the PNG work perfect. It handles all the ugly settings in the background.

Note that while we still have hope for PP, CorelDRAW has always created great alphas in PNGs.

CountZero1942:

I imagine the PNG format is "old-school" where back in the day you had to make your icons or toolbar images with a magenta background and program the settings to make magenta the invisible color. That is to say their color mode is RGB with a specific color used as the transparent color. 

I think PNG has supported an 8 bit alpha since the beginning.

CountZero1942:

Corel doesn't do it right, but a other programs like Paint.NET make the PNG work perfect. It handles all the ugly settings in the background.

Note that while we still have hope for PP, CorelDRAW has always created great alphas in PNGs.

---

Jeff Harrison
Featured Instructor
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Cruise from Los Angeles, California
along the Mexican Riviera
January 17-24, 2009

---

http://coreldraw.com/forums/p/6187/40721.aspx#40721

Paul McGee:

FWIW I have been making several PNGs with perfect transparency from PhotoPaint for many of the last few days. Export for Office, and those go into Power Point just fine. I even had it work with feathered edges. No problems whatever.

Hi Paul,

they "seem" perfect, but there is an anomaly that reveals itself under repeatable conditions, since PP ver 9.

PNGs with little feathering will often work fine.

open the attached CPT, follow these steps

1. Load the CPT. It's a pure file, we can agree.

2. Export as Tiff with transparency. keep CPT open. Note: when viewing a transparent tiff in a quick viewer (like my old ver of ACDSEE, or Irfanview) it may not show the transparency. You'll only see a solid block of color. but the alpha channel is in the file.

3. Export from PP as a transparent 24 bit PNG anyway you like.

4. import your best PNG and the tiff into Draw, place over a background and you'll see. Same thing when brought into other progs.