Strange bright dots in an image

Here everybody can post his problems with PhotoLine
city_zen
Mitglied
Beiträge: 4
Registriert: Di 30 Mär 2010 08:38

Strange bright dots in an image

Beitrag von city_zen »

Hi,

I'm new to PhotoLine (currently evaluating it). So far it looks very good.
Let me also tell you that I'm not an expert in image editors, so please excuse any mistakes on my part in describing my problem.

I've so far tested PhotoLine with a number of images, performing many adjustments on them. No problems at all. Except with one image. This particular image (which I'm attaching to this post) shows some strange bright dots when I open it in PhotoLine. I've opened this same image in other image viewers/editors (IrfanView, XnView, PhotoPlus) and none of them show the bright dots on this image.
Can anyone confirm if this image shows bright dots when opened in PhotoLine? Is it a bug in the image? in PhotoLine? in the user (that would be me :D)?
Please try opening this image both in PhotoLine and in other editors and see if the bright dots are there.
If this is confirmed, does anyone know why this is happening?

Thanks
Du hast keine ausreichende Berechtigung, um die Dateianhänge dieses Beitrags anzusehen.
Andre
Mitglied
Beiträge: 83
Registriert: Sa 29 Sep 2007 14:08

Re: Strange bright dots in an image

Beitrag von Andre »

Hi,

I opened the image in Photoline and can't see any bright dots,where should the dots be located?
Which version of PL and which OS do you use?

Best wishes
Andre

PS: May the effect ist lost due to resizing the image? Can you reproduce the effect with the image from this forum?
city_zen
Mitglied
Beiträge: 4
Registriert: Di 30 Mär 2010 08:38

Re: Strange bright dots in an image

Beitrag von city_zen »

Thanks for your reply, Andre.

I'm using PhotoLine 15.55 on Windows XP SP3
When I look at the picture I attached on my previous post here on the forum using Firefox, I don't see the dots either. But if I copy the image and paste it on PhotoLine (right click on Firefox -> copy image -> Paste as New Document on PhotoLine) I can still see the bright dots. They are located at the bottom of the image and they seem to show up where the darkest parts of the image are. The bright dots persist even if I resize the image (Layout -> Document -> Scale document -> Percent -> 150%).
The only way I've found of making the dots disappear is by changing the layer type from RGB to CMYK (Attributes -> Layer -> Kind -> CMYK). When I do that, the bright dots go away. So the problem may be related to color depth, but my knowledge falls short of being able to pinpoint it. However, the image is an RGB image, so this should be happening, right?
Maybe my monitor/video card settings are wrong? I've just checked the video settings on my system and I'm running at my LCD monitor native resolution (1440 by 900) and 32 bit color. I can only choose between 16 bit color and 32 bit color (i.e. no 24 bit color option).

Any help appreciated.
akeller
Mitglied
Beiträge: 1000
Registriert: Fr 03 Apr 2009 19:10

Re: Strange bright dots in an image

Beitrag von akeller »

*
Zuletzt geändert von akeller am Do 28 Okt 2010 21:37, insgesamt 1-mal geändert.
Andre
Mitglied
Beiträge: 83
Registriert: Sa 29 Sep 2007 14:08

Re: Strange bright dots in an image

Beitrag von Andre »

city_zen hat geschrieben:Thanks for your reply, Andre.
They are located at the bottom of the image and they seem to show up where the darkest parts of the image are.
Hhhm, I can't reproduce this. The bright dots are located in the dark(est) areas of your picture? Maybe the option "Mark extreme values" (Menu: View->Mark Extreme Values) is selected?

Best wishes
Andre
city_zen
Mitglied
Beiträge: 4
Registriert: Di 30 Mär 2010 08:38

Re: Strange bright dots in an image

Beitrag von city_zen »

I changed my monitor's color depth to 16 bit color and the problem went away. Then I restarted my PC and changed back to 32 bit color and (strangely enough) the problem did not come back :?
I'm completely baffled. During my previous test I had uninstalled and reinstalled PhotoLine and the problem was still there.
I think that it's clear now that the problem was due to my monitor and/or video card, not PhotoLine.
I'm sorry for having wasted your time trying to reproduce and debug it.
I'll post here again if I see the problem again, but so far everything's fine.

By the way, the picture is a crop of a much larger image (this one is the original). It shows Mount Fitz Roy in southern Argentina (that's my country :) , but I'm about 2000 km from where that mountain is located)

Thanks.
akeller
Mitglied
Beiträge: 1000
Registriert: Fr 03 Apr 2009 19:10

Re: Strange bright dots in an image

Beitrag von akeller »

*
Zuletzt geändert von akeller am Do 28 Okt 2010 21:36, insgesamt 1-mal geändert.
city_zen
Mitglied
Beiträge: 4
Registriert: Di 30 Mär 2010 08:38

Re: Strange bright dots in an image

Beitrag von city_zen »

akeller hat geschrieben:
city_zen hat geschrieben:By the way, the picture is a crop of a much larger image (this one is the original). It shows Mount Fitz Roy in southern Argentina (that's my country :) , but I'm about 2000 km from where that mountain is located)
Really nice one, I love mountains. Maybe one day I have to come over to Argentina :)
Of course! You'll love it! There a a lot of beautiful landscapes along the Andes.
akeller hat geschrieben: Finally it is good that PL is working for you. I hope you will stick to this nice piece of software.
I think I will, it's a very good program.
Thanks for all your help.

Best,
Pablo
Benutzeravatar
Koyaanis
Mitglied
Beiträge: 217
Registriert: Mo 25 Sep 2006 20:23

Re: Strange bright dots in an image

Beitrag von Koyaanis »

Here's what I suspect is happening, because this has happened to me. Not just with PhotoLine. If I am running a video application or video display on my browser on the desktop behind the image I am trying to view, that video-overlay requires a system frame of transparency to do its thing. If I place an image over that video display, any of the desktop colors defined as transparent for the video-overlay will now bleed through the image wherever that images pixels are of the same transparent color. This can either be all black 0,0,0 or sometimes pure magenta pixels, it depends on the video application. It's a little disconcerting wondering why my image is now peppered with lighter or differently colored pixels. But if you move that still image around over the video-overlay behind it, you'll see that those pixels are just the video bleeding through the image's now-transparent pixels. The first time I saw this happen was when I was trying to select a JPG compression level in another application. Each time I changed the compression the odd peppering of pixels would change. Then I narrowed it down to a browser window open behind the application with a video display showing in it.