Re: Requesting 8-bit grayscale from the converter

• Subject: Re: Requesting 8-bit grayscale from the converter
• From: Paul Danbold <email@hidden>
• Date: Wed, 19 Feb 2003 06:50:32 -0800

I was basing my implicit assumption (that it didn't use to work) on the
attached e-mail. Is this information out of date?

Thanks,
Aaron

--------------------------------------------------
Aaron Sher
Principal Software Engineer
Vanteon Corporation
(585) 248-0510 x250

-----Original Message-----
From: email@hidden
[mailto:email@hidden]On Behalf Of Paul Danbold
Sent: Tuesday, February 18, 2003 5:24 PM
To: email@hidden
Subject: Re: Requesting 8-bit grayscale from the converter


Aaron,

8-bit grayscale (kPMGray_8) is supported on both 10.1.x and 10.2.x.
But the sample code does not do a good job of showing how a PM can
specify and process grayscale output. If your driver is based on the
SamplePM you will need to make the following changes:

1. Specify a grayscale profile in your PrinterInfo ticket. So, for
example, in PMColorDeviceProfiles.xml ...

<dict>
<key>PMColorDeviceProfileID</key>
<integer>1</integer>
<key>PMColorDeviceProfileName</key>
<string>Grayscale</string>
<key>PMColorDeviceProfileURL</key>

<string>file://localhost//System/Library/ColorSync/Profiles/
Generic%20Gray%20Profile.icc</string>
</dict>

2. Tell the converter that you want to use this profile. In the sample
code, the hpVerifyColorSyncProfileID function should, but does not,
return a valid profile id to put into the converter setup ticket. If
the profile id for the grayscale profile is "1", then
hpVerifyColorSyncProfileID() should return "1".

3. The sample code shows how to process color output (kPMXRGB_32) from
the converter. In hpCreateConverterSetup() that means setting
kPMRequestedPixelFormatKey to kPMGray_8, instead of kPMXRGB_32, in the
converter setup ticket. And methods in EnginePCL.cp (e.g. PrintBand)
need to be modified to handle grayscale data.

I hope this helps.

-Paul



On Tuesday, February 18, 2003, at 09:57 AM, Aaron Sher wrote:

I heard a rumor that the converter can now support 8-bit grayscale. Is
this
true? If so, what version was it introduced in?

Thanks,
Aaron

--------------------------------------------------
Aaron Sher
Principal Software Engineer
Vanteon Corporation
(585) 248-0510 x250
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From: "Sher, Aaron" <email@hidden>
Date: Tue Jun 18, 2002 5:48:21 AM US/Pacific
To: "Shadunsky, Alla" <email@hidden>, "McGillivray, Dan" <email@hidden>
Cc: "Guy Wong" <email@hidden>, "Lafford, Ann" <email@hidden>
Subject: FW: TIOGADEV> Greyscale output from PMRasterBand


I guess this answers the question of whether or not we can get better
performance by having the OS do the color-to-grayscale conversion.

Aaron

-----Original Message-----
From: email@hidden
[mailto:email@hidden]On Behalf Of Paul Danbold
Sent: Monday, June 17, 2002 6:23 PM
To: email@hidden
Subject: Re: TIOGADEV> Greyscale output from PMRasterBand


Graham,

This is our bug to fix. It's been the topic of several TiogaDev
emails. It
looks like our code is converting a grayscale profile into a 3

component

colorspace, subsequently setting up an invalid CG context, hence the

error

message you're seeing. For now the recommended workaround is to
request RGB
and do the color->gray conversion in your PM.

-Paul


On 6/17/02 8:21 AM, "Graham Miln" <email@hidden> wrote:

Dear Paul and the Tioga group,

Sorry for not getting back to you about our conversations at the

WWDC.

Things have been nice and busy here. Lots of new printers (and

numerous

older models) to get up and running. I will try and get around to

filing

some bug reports shortly :-)

I am currently trying to get pure greyscale raster data from the Mac

OS

X pre-Jaguar PMRasterBand structure.

Within the BeginJob routine we are passing back the following values

to

the converter via the kPMConverterSetupTicket:

kPMRequestedPixelFormatKey = kPMGray_8
kPMRequestedPixelLayoutKey = kPMDataPlanar

This results in a 1003 printing error being returned via the Print
Center user interface. The console logs the following message from

Core

Graphics:

/System/Library/Printers/Libraries/PrintJobMgr/Contents/MacOS/ PrintJobMg
r:

kCGErrorFailure : CGBitmapContextCreate: unsupported parameter
combination: 8 bits/component; 8 bits/pixel; 3-component colorspace;
kCGImageAlphaNone.

I have tried a few combinations but each time the above error and
message is returned.

Which combination of format and layout should I be using the get 8

bit

greyscale data out of the bands?

Thanks in advance!

Graham
--
Graham Miln, Software Engineer
mailto:email@hidden

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