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Colour Management


JEB

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HI,

Thank you for your speedy reply and link. I raised the question as a result of discussion with a friend who had suspected that this was the case but we wanted to get confirmation which you have now provided.

Thank you

John

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Hi,

Thanks for the replies to my original post.

As ever one question leads to another.

I have posted a non PTE question regarding Colour Management in the Equipment and Software section of the forum to which I would very much appreciate a response from anybody who is knowledgeable on the topic.

Regards

John

P.S. I have tried to leave a link to that post but can't work out how to do it!!!

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I have just read several topics about color management here and it takes me really think about why color management is meant to be so irrelevant topic.

At time when PicturesToExe started sRGB colors where really enough for us. But at nowadays photographers have usually screens with nearly 100% Adobe-RGB support! Of course, converting images to sRGB is really simple using batch processing but making so we have to abandon some really nice hues that sRGB does not support!

After all, our modern conference halls have also projectors that can use Adobe-RGB workspace. Just one example here:

http://www.projectorcentral.com/Canon_REALiS_SX6_projector2.htm

Unfortunately we cannot use PictureToExe anymore for prepearing high quality slideshows for high quality equipment.

So my proposal to PicturesToExe excellent team: please consider usefulness of color management in mind in next development plans.

Arne

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loodusemees,

Sorry, I do not see your problem. PTE is not restricted to sRGB, although there is a rather common misunderstanding in this forum. PTE acts transparent with respect to color management. It just ignores it. And it is good to do so, as color space transformations on the fly (as processed by Photoshop) would have severe consequences on the overall performance. So, what to do? You have to feed PTE with images that have been exported from your image editor (e.g. Photoshop) using the same color profile that has to be used for your monitor. In your example, where your monitor is calibrated to AdobeRGB, your images used with PTE should be AdobeRGB, as well. Of course, there remains a problem. If you take your exe-presentaion (with images set to AdobeRGB) and run it on a second computer having a monitor set to sRGB, then the colors will look flat. For this particular application you have to copy you original AdobeRGB project and use a batch conversion of images to sRGB (but only for the use on the second computer).

All I can say is that using AdobeRGB is by no means a reason, not to use PTE! Of course, there is some room for improvement (and there are competitors with very expensive products which offer this feature): It would be fine if PTE could export exe-presentaions according to predefined ICC-profiles.

Regards,

jt

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It is a mistake to think that aRGB is automatically better than sRGB. sRGB is the world standard, aRGB has theoretically a wider color space, almost entirely in saturated greens, but it is not suitable to use unless the image has been recorded and color managed throughout as an aRGB image. If an aRGB image is shown on sRGB equipment the result is a flat poorly-colored image compared with sRGB.

Your link refers to what appears to be a review piece written to extoll the virtues of a Canon projector but is not a recommendation to use aRGB.

Have a look at http://www.kenrockwell.com/tech/adobe-rgb.htm

It may change your mind about aRGB. Meanwhile, here are some quotes from articles about the two color spaces:

"sRGB came first, and almost everything on a computer is built around sRGB. The internet, video games, applications, personal devices, and most everything else has adapted sRGB as their standard for color space. Even the monitor you’re using likely cannot display all the colors of AdobeRGB. That’s right, most traditional computer monitors can only display about 97% of the sRGB color space, and only about 76% of the AdobeRGB color space. Even screen calibrators will often tell you how much of the color gamut you’re able to display, and since most web browsers have adopted sRGB as its color space, if you upload an image to the internet with the AdobeRGB gamut, the browser will convert it to sRGB, and it’ll do a terrible job at it."

"If you’re not printing your work often, sRGB is the choice of color space for you. It’ll be the surefire way to guarantee that your photos look great on the web, and still look accurate in print. However, if you’re often printing your work, and looking for vibrant colors, AdobeRGB may be the choice for you, it just adds a few steps to your workflow process, as you’ll need to save them as sRGB to correctly display them on the web."

There are about 144,000 articles on color space on Google, so read on if you feel the need. But my strong advice is to use sRGB.

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Dear jt49 and cjdnzi,

and most of all, dear Igor!

Color management means, that in the process of displaying particular media, both, the input media color space (image or video file color profile) and output device calibration profile (screen or projector color capabilities) are taken into account. Correspondingly the best available possibilities and capabilities to show color information are analyzed and used (on a fly). And the image on the monitor or screen is as correct as possible under the particular presentation environment.

The world is not perfect. It is the common myth, that computer displays show full sRGB. No, it is not the case. Even today the average computer (especially laptop) screen or average classroom projector rarely is capable to show 100% sRGB colors. Just default color management, built into Windows operating system assumes default sRGB input. The output colors are as diverse as is the list of computer screens and projectors. And majority of users don't know or don't care.

However, knowledgeable users know, how to use color management and how to get the best possible and repeatable results when displaying images. And to get best possible results, we must use color management even when our images are in sRGB color space. Not to talk about Adobe RGB or ProPhoto RGB.

Maybe 10 years ago, the Adobe RGB monitors and projectors were extremely expensive. Used rarely even in professional world in well paid projects. Today you can buy Adobe RGB capable devices for the reasonable price. In 2012 I paid for the PA241w wide gamut monitor less money than I paid for for the Apple Cinema Display (sRGB) in 2007. Adobe RGB is not as bad, as Ken Rockwell stated in 2006. In 2009 Ken Rockvell also stated, that shooting raw does not give any reasonable benefits over jpg.

Today the color management is a useful feature in multimedia software. Some have it, some not. Tomorrow it is the must feature defining which product survives and which does not. As simple as that.

So far PTE has been excellent product and its capabilities of high quality transitions and animations are state of art. Introducing style features recently has been long waited valuable and useful feature. No complaints whatsoever. Hats down from Igor's team. I have been happy PTE user for years. And I am sure, they can incorporate color management into next PTE release. I hope color management is on top of their ToDo list.

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It is a mistake to think that aRGB is automatically better than sRGB ...

Sorry, I do not see a reason for this statement. I did not say that some color space is better than another one. I just said: Use for your images the same color profile as you use with your monitor. So, if your monitor is calibrated to aRGB, then use aRGB images, but if you use an sRGB monitor, then use sRGB images, as well. In case where you use a non-calibrated system it is difficult to say what would be the best advice, maybe sRGB. If your PTE show is meant to be run on several systems with differing color settings you should prepare several versions of your presentation, one for each color profile of the destination systems.

... most traditional computer monitors can only display about 97% of the sRGB color space, and only about 76% of the AdobeRGB color space ...

I think that monitors have become better. Here are three popular examples (two in the mid-price range, and one in a lower price range): Eizo CX240, NEC PA242W, Dell U2413. All three monitors have been tested (prad.de, tftcentral.co.uk) to provide very precise factory calibration for aRGB and sRGB, in both cases with a very good coverage of the corresponding color space. With these monitors, the choice is easy, aRGB or sRGB. Just do it in the monitor OSD menu.

... But my strong advice is to use sRGB ...

This recommendation may be good in many cases. But as a general statement that has been made to use it without an exception, it is a very bad one. As I said above: Use for your images the same color profile as you use for the destination monitor.

Regards,

jt

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... Color management means, that in the process of displaying particular media, both, the input media color space (image or video file color profile) and output device calibration profile (screen or projector color capabilities) are taken into account. Correspondingly the best available possibilities and capabilities to show color information are analyzed and used (on a fly). And the image on the monitor or screen is as correct as possible under the particular presentation environment ... I hope color management is on top of their ToDo list.

It would be fine if you could make a suggestion what to do (I have made one). As I said above, color management on the fly would be bad for the performance.

Regards,

jt

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It would be fine if you could make a suggestion what to do (I have made one). As I said above, color management on the fly would be bad for the performance.

Regards,

jt

Your suggestion was to convert images to particular monitor profile. It is cumbersome workaround and can be used only by yourself. You need a source project with 16-bit ProPhoto RGB images (not supported by the PTE at the moment) or if you are not that kind of purist, Adobe RGB will do (although my cheap LV8320 projector can display better yellows that Adobe RGB). Then each time you have to convert all images to destination color profile for particular environment. It is a workaround but only for yourself. Imagine Photoshop or other image editor not being color managed and having suggestions endlessly convert your images to particular device profile... It will end up in total mess.

Imagine you have made an exe to be distributed and used in schools as educational material. And some schools have knowledgeable IT specialist and they have calibrated projectors. There is no way to convert images but why should they be punished? The only solution is to add hotkey to open corresponding menu to set color management settings. And/or you can set any software to check and use operation system color management settings. That's why I made suggestion to PTE developers - implement color management.

During its development PTE has been always a resource demanding software with clear dedication to high quality presentations. For a while it had even two options - with or without hardware acceleration. On less powerful computers you could not use particular features. If the color management on the fly could affect some animations, just add two options like earlier - these features can be color managed, and these can't. The users can make their decisions. I can survive with a bit less bells and whistles in return for accurate colors. Or to upgrade hardware like earlier days.

Actually I doubt, that color management implementation has that large impact on performance. Let Igor tell us his opinion.

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Many thanks to all, who have taken time to enhance this topic!

I would like to summarize some important aspects here.

1. Both AdobeRGB and sRGB have their pros & cons. Nice comparison about it can be read here.

2. JPEG files can hold up to 16.7 million colors. It is reasonable to use this space in a reasonable way. The essential power of AdobeRGB is to represent more accurately the hues of green. The latter is really important in nature photography: green is the most abundant color in forest areas and at same time it is the most perfectly perceived color by human eye. Why we have used (expensive) Fuci Velvia slide film for our landscape photography? Older photographers know...

3. As different monitors and projectors render colors differently we need color management even if our images are in sRGB color space! Presenting our slideshows in different places we have no idea which kind of projector we are going to use. Without using the color management it is impossible to prepare our slideshow ready at home. But it is simple enough to make special color profile of unknown equipment before slideshow using our calibrator...

4. Color management implementation has surely impact on performance. But how large? Last week I had to use my 9-years old laptop for presenting PTE shows due to problems with my new computer. All worked well (pictures with longest side of 2000 pixels + simple effects + music & nature sounds).

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4. Color management implementation has surely impact on performance. But how large?

Actually I think, the impact on performance would not be that large if at all. The color aware software knows (reads) the source profiles of the images and videos. When rendering final image to be displayed through color managed OS, all the software has to do, is to pass that profile information over to OS. The OS now accomplishes necessary conversion on the fly as the pixel values are sent through the video card to the monitor.

The only problem I see, could be users mixing images/videos having too large diversity of different profiles. But when compiling slideshow, PTE can warn users in case of too many profiles or missing profiles. Just like it does excellent job checking videos and offering conversion options.

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  • 2 weeks later...

Hi folks,

At our Northern Ireland Photographic Association (NIPA) judging events, we always calibrate our projector, with the laptop. Only certain programs acknowledge the new 'profile', Lightroom and View NX, being two we use. It would seem that PTE is not colour managed and defaults to the Windows sRGB profile. Is there any way that I can use PTE within a colour managed and profiled system?

Mark Allen

NIPA Sec.

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Thank you jt49 for your quick reply.

I had read the previous posts that related to colour management and the ongoing debate of sRGB _V_ Adobe RGB. But I was talking about projector calibration and profiles. Which, although similar, are not (I suspect) exactly the same thing.

Calibrating the projector with the computer at each different venue, takes into consideration the distance of the projector to the screen and the screen's reflective capacity. The calibration process only takes between 15-25 minutes, but ensures the colours are correct, when the computer and projector are calibrated. We use Lightroom to display our 'projected digital images' as Lightroom will use the new calibrated profile, as default. So will View NX; but other programs, like Faststone Image Viewer, Window Gallery/Media Player do not.

There is a small, but significant difference, when displaying the same images using Lightroom, Faststone and Windows Gallery / Media Player. Lightroom and View NX, as they accept the calibrated profile show the images, exactly the same. Faststone produces a different colour balance and highlights are often blown out (where they are not blown out when using Lightroom or View NX). Windows Gallery / Media player is worst of all, it produces the deadly digital green, that again is not present when using Lightroom or View NX.

All of this causes problems when members see their work, projected, and complain that the colours are wrong!

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You must have lost the main aspect of the discussion above as the consequence of the ongoing and fruitless dispute which color space is the best one, and the bad advice to use sRGB in any case. You will obtain what you want to have, but only in one of the next versions. Some future version of PTE will have color management on the fly, see the topic here. At present time, PTE acts in a transparent manner. You have to feed PTE with images having the color profile of your output device. If you calibrate your output device according to a given fixed profile, then you may use it. If the output profile changes frequently, you need color transformation on the fly, and you have to wait for the new version of PTE.

Regards,

jt

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