Save For Web embeds 1.8 gamma chunk in png?

"Steven" wrote in message

It appears to me that Photoshop is embedding a gamma chunk in png images created with "Save For Web". This chunk has a hard coded value of 0.55 which is the reciproce of 1.8. Apparently Photoshop assumes all Mac users have their monitors calibrated with gamma 1.8. Is there no way to make Photoshop use a different value? My (Mac) monitor uses gamma 2.2…
Also, when I use "Save As" to create a png image the color profile is embedded even while the "embed profile" is unchecked and grayed out.. This seems odd to me.

—
Steven

I saw a tutorial on this
if I can find it I will report back

"Steven" wrote in message

It appears to me that Photoshop is embedding a gamma chunk in png images created with "Save For Web". This chunk has a hard coded value of 0.55 which is the reciproce of 1.8. Apparently Photoshop assumes all Mac users have their monitors calibrated with gamma 1.8. Is there no way to make Photoshop use a different value? My (Mac) monitor uses gamma 2.2…
Also, when I use "Save As" to create a png image the color profile is embedded even while the "embed profile" is unchecked and grayed out.. This seems odd to me.

—
Steven

found it!!!!

http://user.fundy.net/morris/?photoshop03.shtml

KatWoman wrote:

"Steven" wrote:

It appears to me that Photoshop is embedding a gamma chunk in png images created with "Save For Web". This chunk has a hard coded value of 0.55 which is the reciproce of 1.8. Apparently Photoshop assumes all Mac users have their monitors calibrated with gamma 1.8. Is there no way to make Photoshop use a different value? My (Mac) monitor uses gamma 2.2…
Also, when I use "Save As" to create a png image the color profile is embedded even while the "embed profile" is unchecked and grayed out.. This seems odd to me.

found it!!!!

http://user.fundy.net/morris/?photoshop03.shtml

Thanks. This tutorial is giving a workaround for the gamma problem in Photoshop 5+.

What it basically says is:

Problem:
Photoshop writes png files with correct data with an incorrect gamma description in it.

Workaround:
Change the data (using the levels control) to compensate for the incorrect gamma information in the file.

Shifting all your image data to compensate to an incorrect indicator can’t be good for image quality.

The tutorial also states that browsers ignore the gAMA chunk in png images. This is not true (anymore?).

Anyway, the problem I have is that Photoshop CS today is still not doing this correctly. And Photoshop is a very expensive professional application. How does Adobe get away with this?

Sorry, no offense to you KatWoman.. Thanks for the effort.

—
Steven

"Steven" wrote in message

KatWoman wrote:

"Steven" wrote:

It appears to me that Photoshop is embedding a gamma chunk in png images created with "Save For Web". This chunk has a hard coded value of 0.55 which is the reciproce of 1.8. Apparently Photoshop assumes all Mac users have their monitors calibrated with gamma 1.8. Is there no way to make Photoshop use a different value? My (Mac) monitor uses gamma 2.2…
Also, when I use "Save As" to create a png image the color profile is embedded even while the "embed profile" is unchecked and grayed out.. This seems odd to me.

found it!!!!

http://user.fundy.net/morris/?photoshop03.shtml

Thanks. This tutorial is giving a workaround for the gamma problem in Photoshop 5+.

What it basically says is:

Problem:
Photoshop writes png files with correct data with an incorrect gamma description in it.

Workaround:
Change the data (using the levels control) to compensate for the incorrect gamma information in the file.

Shifting all your image data to compensate to an incorrect indicator can’t be good for image quality.

The tutorial also states that browsers ignore the gAMA chunk in png images. This is not true (anymore?).

Anyway, the problem I have is that Photoshop CS today is still not doing this correctly. And Photoshop is a very expensive professional application. How does Adobe get away with this?

Sorry, no offense to you KatWoman.. Thanks for the effort.

—
Steven

well since 98% of the public is using IE to view the PNG files, all the great features of it being transparent are not viewable by most of the people. The support for PNG is just not there.
Is it a MS conspiracy to ignore all open source formats? they just don’t care about us web designers?
It does seem Adobe has the very same attitude about the format, they don’t care to devote any meaningful developments to it.
it would seem that a company so aware of PC vs Mac gammas being different would welcome a format that is controllable on that feature. Until the time that PNG transparency becomes usable in web browsers used by the majority of people I will not be using it any web page designs. For now we are left with jpg and the very crappy gif. Both of which Adobe has to pay royalties for using!!! It is very perplexing that a free, open sourced, superior compression format that has been around since 1997, is not being used by the leading software companies.
Supposedly IE 7 will be able to use alpha transparency. Looking forward to it’s release.

KatWoman wrote:

"Steven" wrote in message

KatWoman wrote:

"Steven" wrote:

It appears to me that Photoshop is embedding a gamma chunk in png images created with "Save For Web". This chunk has a hard coded value of 0.55 which is the reciproce of 1.8. Apparently Photoshop assumes all Mac users have their monitors calibrated with gamma 1.8. Is there no way to make Photoshop use a different value? My (Mac) monitor uses gamma 2.2…
Also, when I use "Save As" to create a png image the color profile is embedded even while the "embed profile" is unchecked and grayed out.. This seems odd to me.

found it!!!!

http://user.fundy.net/morris/?photoshop03.shtml

Thanks. This tutorial is giving a workaround for the gamma problem in Photoshop 5+.

What it basically says is:

Problem:
Photoshop writes png files with correct data with an incorrect gamma description in it.

Workaround:
Change the data (using the levels control) to compensate for the incorrect gamma information in the file.

Shifting all your image data to compensate to an incorrect indicator can’t be good for image quality.

The tutorial also states that browsers ignore the gAMA chunk in png images. This is not true (anymore?).

Anyway, the problem I have is that Photoshop CS today is still not doing this correctly. And Photoshop is a very expensive professional application. How does Adobe get away with this?

Sorry, no offense to you KatWoman.. Thanks for the effort.

well since 98% of the public is using IE to view the PNG files, all the great features of it being transparent are not viewable by most of the people. The support for PNG is just not there.

Yes. But that can’t be an excuse for Adobe to offer an incorrect implementation.

Is it a MS conspiracy to ignore all open source formats? they just don’t care about us web designers?

No, they don’t.

It does seem Adobe has the very same attitude about the format, they don’t care to devote any meaningful developments to it.
it would seem that a company so aware of PC vs Mac gammas being different would welcome a format that is controllable on that feature. Until the time that PNG transparency becomes usable in web browsers used by the majority of people I will not be using it any web page designs.

Well, there is a way to make it work in Explorer with an activeX filter, if I’m not mistaken…

—
Steven

"Steven" wrote in message

KatWoman wrote:

"Steven" wrote in message

KatWoman wrote:

"Steven" wrote:

It appears to me that Photoshop is embedding a gamma chunk in png images
created with "Save For Web". This chunk has a hard coded value of 0.55 which is the reciproce of 1.8. Apparently Photoshop assumes all Mac users
have their monitors calibrated with gamma 1.8. Is there no way to make Photoshop use a different value? My (Mac) monitor uses gamma 2.2…
Also, when I use "Save As" to create a png image the color profile is embedded even while the "embed profile" is unchecked and grayed out.. This seems odd to me.

found it!!!!

http://user.fundy.net/morris/?photoshop03.shtml

Thanks. This tutorial is giving a workaround for the gamma problem in Photoshop 5+.

What it basically says is:

Problem:
Photoshop writes png files with correct data with an incorrect gamma description in it.

Workaround:
Change the data (using the levels control) to compensate for the incorrect gamma information in the file.

Shifting all your image data to compensate to an incorrect indicator can’t be good for image quality.

The tutorial also states that browsers ignore the gAMA chunk in png images. This is not true (anymore?).

Anyway, the problem I have is that Photoshop CS today is still not doing this correctly. And Photoshop is a very expensive professional application. How does Adobe get away with this?

Sorry, no offense to you KatWoman.. Thanks for the effort.

well since 98% of the public is using IE to view the PNG files, all the great features of it being transparent are not viewable by most of the people. The support for PNG is just not there.

Yes. But that can’t be an excuse for Adobe to offer an incorrect implementation.

Is it a MS conspiracy to ignore all open source formats? they just don’t care about us web designers?

No, they don’t.

It does seem Adobe has the very same attitude about the format, they don’t care to devote any meaningful developments to it.
it would seem that a company so aware of PC vs Mac gammas being different would welcome a format that is controllable on that feature. Until the time that PNG transparency becomes usable in web browsers used by the majority of people I will not be using it any web page designs.

Well, there is a way to make it work in Explorer with an activeX filter, if I’m not mistaken…

—
Steven

yes there is a work around involving some code on each and every web page in the site, but it also makes it invisible altogether in OPERA and/or Mac I forget which because it has no <IMG> tags.
Nowadays all active x is blocked by default which is how most users have it set so they get a warning to override for any active x. I think a lot of users simply won’t open it.
I use the lowest common denominator in designing websites, html jpg gif mp3 stuff everyone can see
I sometimes use Flash but then again I think a lot of users just won’t/can’t download the viewer.

KatWoman wrote:

"Steven" wrote in message

KatWoman wrote:

—8<—

It does seem Adobe has the very same attitude about the format, they don’t care to devote any meaningful developments to it.
it would seem that a company so aware of PC vs Mac gammas being different would welcome a format that is controllable on that feature. Until the time that PNG transparency becomes usable in web browsers used by the majority of people I will not be using it any web page designs.

Well, there is a way to make it work in Explorer with an activeX filter, if I’m not mistaken…

yes there is a work around involving some code on each and every web page in the site, but it also makes it invisible altogether in OPERA and/or Mac I forget which because it has no <IMG> tags.
Nowadays all active x is blocked by default which is how most users have it set so they get a warning to override for any active x. I think a lot of users simply won’t open it.
I use the lowest common denominator in designing websites, html jpg gif mp3 stuff everyone can see
I sometimes use Flash but then again I think a lot of users just won’t/can’t download the viewer.

Microsoft is indeed a stifling factor in web design. But that can’t be an excuse for Adobe to offer an incorrect implementation. If I pay more than a thousand euro’s for a professional image editor I want it to do things correctly and not hide behind the lame behavior of some monopolist software maker from Redmond. After all who is dictating that I create my images for Explorer? I may have an intranet project that is Microsoft-free. The principle alone of getting it right is important! Oh well… @#$%

—
Steven

"Steven" wrote in message

KatWoman wrote:

"Steven" wrote in message

KatWoman wrote:

—8<—

It does seem Adobe has the very same attitude about the format, they don’t care to devote any meaningful developments to it.
it would seem that a company so aware of PC vs Mac gammas being different would welcome a format that is controllable on that feature. Until the time that PNG transparency becomes usable in web browsers used by the majority of people I will not be using it any web page designs.

Well, there is a way to make it work in Explorer with an activeX filter, if I’m not mistaken…

yes there is a work around involving some code on each and every web page in the site, but it also makes it invisible altogether in OPERA and/or Mac I forget which because it has no <IMG> tags.
Nowadays all active x is blocked by default which is how most users have it set so they get a warning to override for any active x. I think a lot of users simply won’t open it.
I use the lowest common denominator in designing websites, html jpg gif mp3 stuff everyone can see
I sometimes use Flash but then again I think a lot of users just won’t/can’t download the viewer.

Microsoft is indeed a stifling factor in web design. But that can’t be an excuse for Adobe to offer an incorrect implementation. If I pay more than a thousand euro’s for a professional image editor I want it to do things correctly and not hide behind the lame behavior of some monopolist software maker from Redmond. After all who is dictating that I create my images for Explorer? I may have an intranet project that is Microsoft-free. The principle alone of getting it right is important! Oh well… @#$%

—
Steven

well we are not alone,
sign the petition?
http://www.petitiononline.com/msiepng/petition.html