Problems with .png files

[fh1805]

Hi folks,

I've hit a problem with some *.png files in PTEv5 and cannot seem to be able to get to the bottom of it.

I have three png files that I created using Adobe Photoshop Elements v5 on my desktop PC which is running under Windows Vista Home Premium..

The creation technique for all three was as follows:

Open original jpg image (Background layer)

Crop to keep just the part I want

Create a new layer (Layer1)

Select from the Background layer using the Elliptical Marquee tool

Copy the selection

Paste the selection into Layer1

Delete the Background layer

File Save As filename.png - taking all defaults except that I turn off "Include in Organizer"

When I open these again in Adobe Photoshop Elements v5 they look just as I would expect and as I want them to look. When I go into PTEv5 to add them to a background image they appear in a corrupt form in the Selected Directory Window (to use the term that Lin and Jeff use in their excellent User Guide). Note - they appear corrupt in PTEv5 before I even try and select them. If I go on and select them into the slide list, they come in in their corrupt form.

When I open the same directory into Windows Explorer they appear in their uncorrupt form. If I right-click on one of them in Windows Explorer and Preview it, it is correct.

The problem persists even across a power-off/power-on of the PC.

Other png files (created from within PTEv5 by rasterizing text items) give me no problems.

I'm going to copy the png files via a memory stick to my laptop which runs PTEv5 under Windows XP Home Edition SP2. Will post again with results of that test.

[fh1805]

Hi again,

Been there, done that, got the results... I copied the suspect files onto a memory stick using Windows Explorer. I then took the memory stick to my laptop, which runs under Windows XP. I accessed the png files directly off the memory stick (drive F:) and opened them in Windows Picture and Fax Viewer. They looked just fine.

I then launched PTEv5 and navigated to drive F:. The images were corrupt when viewed in the Selected Directory Window and, indeed, look to be corrupt in exactly the same manner as on the desktop PC.

It looks to me like the problem is in PTEv5.

[Barry Beckham]

Hi again,

Been there, done that, got the results... I copied the suspect files onto a memory stick using Windows Explorer. I then took the memory stick to my laptop, which runs under Windows XP. I accessed the png files directly off the memory stick (drive F:) and opened them in Windows Picture and Fax Viewer. They looked just fine.

I then launched PTEv5 and navigated to drive F:. The images were corrupt when viewed in the Selected Directory Window and, indeed, look to be corrupt in exactly the same manner as on the desktop PC.

It looks to me like the problem is in PTEv5.

Try this to see if the problem is PTE5 or Elements 5. Download a png file I have made from the link below and try that in your PTE5. Right click the link and choose save target as.

See if this file shows up corrupt on PTE5. If it does the issue does appear to be with PTE5, if it doesn't the issue appears to be Elements 5

http://www.beckhamdigital.co.uk/test.png

[Ken Cox]

Barry's file WORKS IN MY

PicturesToExe 5.0 (June 18, 2007)

xp system

ken

[fh1805]

Barry/Ken,

Thanks for the prompt responses to my post.

I've downloaded Barry's file and taken it into PTEv5.03 on my Vista system. No problems!

Barry, would I be right in thinking you created that png file by rasterizing some text from within PTEv5 O&A?

In the sequence that I am building I have 23 other png files that all work OK. Most of them are rasterized text (Title slidess, End-credits slides and some image captions) But, and here is what I think is the significant bit, there are four images that are png files produced using Adobe Photoshop Elements v5 and following the technique I described in my original post. I created those four png files last night and put them in the sequence. I created the other three (the ones that give me a problem) this morning - and these three flatly refuse to play ball with me!

There is a marked difference between the three non-text images that don't work and the four non-text images that do. The three that don't work were created from Grayscale originals and have wide transparent borders. The four that do work were created from colour originals and have colour all the way to the edge.

Isn't it strange how simply talking through a problem can identify new avenues of investigation? Could the problem area be Grayscale vs RGB colour? I know I can readily lay my hands on the original postcard of one of the three images and rescan it as a colour image instead of grayscale.

I'll give this a try and post the results shortly.

Thanks for being such excellent sounding boards!

[fh1805]

Bingo!

I've rescanned the old postcard that was giving me grief as a colour original and created a new png file from it. Everything works exactly as expected!

I then rescanned the same postcard as a grayscale original and created a new png file from it. The image looked right in Photoshop but when I tried to add it as an object in PTEv5.03, PTE came back saying "Image load error" and the image showed that same manner of apparent corruption that I had previously witnessed. I never got this "Image load error" message on any of my previous attempts to get this particular image to work.

I'm happy that I seem to have a work-around to my problems. I just need to rescan the other images as colour rather than grayscale.

But I'm left with some as yet unanswered questions.

- Does png file format actually support grayscale images?

- If it does support them, is there a bug in the implementation of png file support in PTEv5.03?

Once again, thanks for being sounding boards for this problem. Hope somebody can answer the remaining questions.

[Ken Cox]

PETER

before you dispose of the problem slides why not post them up to mediafire and more of us can test them -- somebody on forum may be able to determine the prblem

ken

[davegee]

The same problem existed in PS7 with Greyscale JPEG images.

Try converting the Greyscale image to RGB and then save as PNG24.

That might work.

DaveG

[Barry Beckham]

I just created the PBG file through photoshop, but the problem you have experienced may just be down to a computer glitch, one of those things you may never get to the bottom of.

Sometimes we can create hundreds of images and when we open them back up again a couple may say there is a problem or a corruption that has never happened before and doesn't happen again.

[fh1805]

Hi everyone,

I've followed Ken's advice an uploaded a zip file of the image files to Mediafire (see link below)

http://www.mediafire.com/?ejotnzcmx3k

The zip contains:

an RGB original scan

an RGB cropped png taken from that original

a Grayscale original scan

a Grayscale cropped png taken from that original

I'm interested to know if anyone else hits any problems with the Grayscales.

[fh1805]

All,

Sorry it took me so long to come back to the forum but, having found a workaround that was acceptable to me, I've been slaving over a hot PC building my new show.

DaveG,

That is what I eventually did. I only experience a problem if a try and produce a png file from a grayscale original.

Barry,

I suppose it might be just a computer glitch - but it is a glitch that I can recreate consistently if I use a grayscale original to create a png file. That doesn't feel or smell like a glitch it feels or smells like either a product restriction or a bug. Which software is at fault, if any are, is an open question. Maybe those who download the zip file from MediaFire might be able to isolate that for us.

[Ken Cox]

Peter

have never ran a png developed show but with your files and Barry's test png , putthem in a show with v5 pte default settings other than set with straight fades and show worked perfect as far as i can determine - there is one slide that is black but the lady ended up in an oval

exe and the pte file in zip

ken

peter_TEST_PNG.zip

[jfa]

...<snip>...I'm happy that I seem to have a work-around to my problems. I just need to rescan the other images as colour rather than grayscale...<snip>...

As a general rule it is better to do all your scans, (B/W original or not), for work in Photoshop as full colour scans no-matter what the end result will be. This will ensure that you get the maximum amount of data to work with in Photoshop and give a better end result.

It is better to discard some information latter than not have enough at the start.

EDIT 8:30AM

All the test images I downloaded worked in my PTE v5 fine. Just loaded and ran with all defaults set.

[fh1805]

Ken/John,

Thanks for the feedback re the zipped file that I posted.

Can I just check one or two points with you both, please? I want to be certain that, when comparing your system's behaviour with mine, that we're not comparing apples and oranges.

All you did was download the four images; then, in a new project file, placed them into the slide list. A simple four image show with all defaults. Right? (Ken, I note your comment about turning off the fancy fades - I do that myself).

And when you previewed that show all four images appeared as you would have expected them to. Right?

Just to be sure we have identical set ups, could you please ensure that the image sequence is Gray Original, Gray png, RGB original, RGB png.

My question for you both is: Do you actually see the Gray png displayed? It should be almost the same image as the RGB png but, obviously, in grayscale.

I have just built a simple four image project as above and I don't get the image of the Gray png displayed. All I get is a black screen (i.e. it's showing me only the default background in PTE). The other three images all display with no problem.

A few final points:

What version of operating system are you running on?

What version of PTE are you running on?

What software did you use to unzip the file?

[Ken Cox]

PicturesToExe 5.0 (June 18, 2007) -- i never updated past that date although there were several minor updates thereafter

xp sp2 system

winzip

what showed in the exe in the zip i posted above?

the pte is also in the zip

i included Barry's file in the exe

slide sequence is

barry's test png slide

grayorig jpg

grayorig png -- but when i look at it in the window it reveals your error messsage

rgborig jpg

rgbpng png

see screenshots

so the show shows

test

gray orig

a black slide

sepia toned org

lady in oval black frame -- it shows white in screen shot but in o/a it is black oval around her face

nice even if it is not correct:)

ken

[fh1805]

Hi Ken,

Sorry I didn't respond to your zip file in any of my previous posts. I was under severe time pressures this morning.

I've now had chance to download your zip and run the exe file. You see exactly the same as I do. Where the graypng should be is just the default black background.

By the way, to educate you a little, the RGBpng image has the appearance that you describe because the area other than for the lady's face (my grandmother as a young woman) is transparent. So the final image as you see it is a combination of the default black background and the vignetted portrait. If you change the background via Project Options...Screen...Background...Solid Color and then pick a different colour to black you'll see what I mean.

In the sequence that I am working on, I use this image as an Object superimposed on a letter that my grandfather wrote to her from the Western Front in World War One.

However, I digress: back to the problem...

You get exactly the same as me on your XP system. So the problem is not specific to any one operating system.

Hey, this is getting interesting. I've just done some more tests.

I took the RGBPNG.png image into Adobe Photoshop Elements v5 and did Enhance...Convert to B&W.. and took defaults.

I saved this image as RGBGray.png

I took the RGBPNG.png image into Elements for a second time but this time did Image...Mode...Grayscale and took defaults

I saved this image as RGBGMod.png

I then opened my four slide test project in PTEv5. Even before I added these two new images I could see that RGBGray.png looked A-OK whereas RGBGMod was showing the corruption.

So it would appear to be a Photoshop behavioural issue. Now all we need is for a Photoshop expert on the forum to explain the difference between: Convert to B&W and Change Mode to Grayscale. In the visual appearance within Photoshop I'm damned if I can see any difference. But there clearly is a big difference in the resultant png files.

Once again, Ken, my thanks for your time both listening and suggesting.

[Ken Cox]

UP TILL A FEW MONTHS AGO I FIGGERED A PNG WAS A SPELLING MISTAKE FOR PING - and thought Igor was really going far out -- thought he was maybe getting another "one up" on the proshow aficionado's:)

guess you have it under control now

ken

[alrobin]

So it would appear to be a Photoshop behavioural issue. Now all we need is for a Photoshop expert on the forum to explain the difference between: Convert to B&W and Change Mode to Grayscale. In the visual appearance within Photoshop I'm damned if I can see any difference. But there clearly is a big difference in the resultant png files.

I'm not an "expert" but here is a reference that sheds some light on the difference between "grayscale" and "RGB" modes in PS:

http://www.adobepress.com/articles/article...qNum=6&rl=1

It boils down to a difference in modes - grayscale mode is only B&W, whereas RGB can be B&W as well as colour.

PNG is supposed to support both grayscale and RGB, so I don't know the reason for the unexpected results in PTE that some are experiencing.

[fh1805]

Al,

Thanks, that's increased my knowledge but it's left me no wiser as to why things are happening as they are. The only consolation, so far, is that someone else (Ken) can recreate the problem on his system. So at least it isn't just a glitch on my hardware/software combination.

[davegee]

Hope you don't mind me saying this guys but you are covering OLD GROUND.

We discussed it a while ago - the GLITCH was in PS6 or 7 a few years ago and has possibly turned up again in Elements 5. Ever since CS you are able to create a JPEG or PNG from a greyscale file.

Al should have reference to it somewhere - Igor was delighted to hear that it was Photoshop problem.

DaveG

[Ken Cox]

I went back into my faq file and found this link -- the dates may assist people in pursuing the adobe problem

http://www.libpng.org/pub/png/spec/

i had saved it aug 21 2005

also

this

Feb 21 2006, 04:37 PM

http://www.picturestoexe.com/forums/index.php?showtopic=4116

ken

[jfa]

Ken/John,

Thanks for the feedback re the zipped file that I posted.

Can I just check one or two points with you both, please? I want to be certain that, when comparing your system's behaviour with mine, that we're not comparing apples and oranges.

All you did was download the four images; then, in a new project file, placed them into the slide list. A simple four image show with all defaults. Right? (Ken, I note your comment about turning off the fancy fades - I do that myself).

And when you previewed that show all four images appeared as you would have expected them to. Right?

Just to be sure we have identical set ups, could you please ensure that the image sequence is Gray Original, Gray png, RGB original, RGB png.

My question for you both is: Do you actually see the Gray png displayed? It should be almost the same image as the RGB png but, obviously, in grayscale.

I have just built a simple four image project as above and I don't get the image of the Gray png displayed. All I get is a black screen (i.e. it's showing me only the default background in PTE). The other three images all display with no problem.

A few final points:

What version of operating system are you running on?

What version of PTE are you running on?

What software did you use to unzip the file?

Peter, sorry for not replying sooner, my server had crashed last night and I have been locked off the NET until this morning. It's a jolt when you lose it and to realise how much we depend on it these days.

Re your problem: I had the order incorrect and saw the blank screen at the start and thought, (incorrectly), that it was the startup of PTE. Yes I see your problem when I put the images in the order you requested.

I went through the process of making a png file from a grayscale image in CS3, then loading into PTE and all worked fine. Don't have Elements 5 so I can't test it but as stated above it could be the answer. I have never seen this problem before and have worked with png files in Elements 3-4, PS7 through to CS3, although I have always scanned in the maximum colour depth to keep image quality at the highest, then converted to grayscale after all image manipulation was completed just before the final conversion to png.

[alrobin]

Al should have reference to it somewhere - Igor was delighted to hear that it was Photoshop problem.

The article I referenced in my previous post alludes to an old problem with certain image editors and the way they handle png files. However, I'm surprised it's surfacing again, considering recent updates to PS and PS elements.

[fh1805]

Thanks to all those who have contributed replies to this thread. I really appreciate the help that all you experienced PTE users give so freely.

I'm satisfied that the problem I encountered was neither a PTE bug nor a "user error" on my part in my use of PTE. I now know that I have hit an apparent bug in Photoshop Elements v5 but, thanks to your collective input, I have a good reliable workaround which is entirely acceptable to me.

As far as I am concerned this thread is now closed. Once again thanks to you all.

[Igor]

Thanks!

It's a bug in PicturesToExe 5.03 which doesn't support 8-bit grayscale image with alpha channel. We just fixed it in future v5.1

I'll publish updated 5.04 with this fix tomorrow.

As temporal solution please save this PNG file as 24-bit image with alpha channel.