[solved] Re: How to get rid of a biased colour profile?

Ralf Mardorf silver.bullet at zoho.com
Mon May 27 15:11:02 BST 2019


On Mon, 2019-05-27 at 15:32 +0200, Boudewijn Rempt wrote:
> If you use that profile, you're using something really weird, because
> that's a very special profile meant for use with HDR images. In your
> earlier mail, you omitted to tell us which color model/channel
> depth/profile you were using for the image, and what the color
> management settings in Krita's settings dialog were.
> 
> If your image is 8 bit / rgba / sRGB with srgbtrc and your display
> profile is srgb as well, and you save as srgb png, and your monitor is
> set to sRGB then the image on the wallpaper and in Krita must look the
> same.

Let's keep it short, I already wasted to much time with this issue, to
get a broken artwork. The artwork is broken on it's own, no export
needed, since Krita's default view profile was broken and I wasn't aware
of it.

If I display a picture with Krita, then by default I expect that it
looks the same as when viewed with any other app, such as a simple
viewer such as feh or mirage, a web browser such as Firefox or Chrome,
as well as with other pixel manipulating software, such as Gimp. Krita
didn't, by using the defaults. I mentioned the used default somewhere by
the provided links.

My EIZO monitor does run with user defined settings, not with EIZO's
sRGB profile, but without taking a look to the details, if I switch
between my user profile and the EIZO default sRGB mode, it makes no
visible difference.

Krita's default was sRGB-elle-V2-srgbtrc.icc.
What ever is chosen by the
color general tab doesn't make a difference.
Not my artwork, but as a reference I loaded a photo done with an iPad
with several apps:

$ exiftool /home/rocketmouse/Pictures/cornflower_wall_plain-2019-may/IMG_2788.JPG 
ExifTool Version Number         : 11.30
File Name                       : IMG_2788.JPG
Directory                       : /home/rocketmouse/Pictures/cornflower_wall_plain-2019-may
File Size                       : 3.9 MB
File Modification Date/Time     : 2019:05:25 08:58:44+02:00
File Access Date/Time           : 2019:05:27 15:54:10+02:00
File Inode Change Date/Time     : 2019:05:26 15:40:22+02:00
File Permissions                : rw-r--r--
File Type                       : JPEG
File Type Extension             : jpg
MIME Type                       : image/jpeg
Exif Byte Order                 : Big-endian (Motorola, MM)
Make                            : Apple
Camera Model Name               : iPad Pro (12.9-inch) (3rd generation)
Orientation                     : Horizontal (normal)
X Resolution                    : 72
Y Resolution                    : 72
Resolution Unit                 : inches
Software                        : 12.3
Modify Date                     : 2019:05:24 12:46:45
Y Cb Cr Positioning             : Centered
Exposure Time                   : 1/168
F Number                        : 1.8
Exposure Program                : Program AE
ISO                             : 16
Exif Version                    : 0221
Date/Time Original              : 2019:05:24 12:46:45
Create Date                     : 2019:05:24 12:46:45
Components Configuration        : Y, Cb, Cr, -
Shutter Speed Value             : 1/168
Aperture Value                  : 1.8
Brightness Value                : 6.60319106
Exposure Compensation           : 0
Metering Mode                   : Spot
Flash                           : Auto, Did not fire
Focal Length                    : 3.0 mm
Subject Area                    : 3649 2641 751 753
Run Time Flags                  : Valid
Run Time Value                  : 770375864504541
Run Time Scale                  : 1000000000
Run Time Epoch                  : 0
Acceleration Vector             : -0.9236037728 -0.02263331227 -0.3712795378
Sub Sec Time Original           : 650
Sub Sec Time Digitized          : 650
Flashpix Version                : 0100
Color Space                     : Uncalibrated
Exif Image Width                : 4032
Exif Image Height               : 3024
Sensing Method                  : One-chip color area
Scene Type                      : Directly photographed
Exposure Mode                   : Auto
White Balance                   : Auto
Focal Length In 35mm Format     : 29 mm
Scene Capture Type              : Standard
Lens Info                       : 3mm f/1.8
Lens Make                       : Apple
Lens Model                      : iPad Pro (12.9-inch) (3rd generation) back camera 3mm f/1.8
Compression                     : JPEG (old-style)
Thumbnail Offset                : 1916
Thumbnail Length                : 11610
Profile CMM Type                : Apple Computer Inc.
Profile Version                 : 4.0.0
Profile Class                   : Display Device Profile
Color Space Data                : RGB
Profile Connection Space        : XYZ
Profile Date Time               : 2017:07:07 13:22:32
Profile File Signature          : acsp
Primary Platform                : Apple Computer Inc.
CMM Flags                       : Not Embedded, Independent
Device Manufacturer             : Apple Computer Inc.
Device Model                    : 
Device Attributes               : Reflective, Glossy, Positive, Color
Rendering Intent                : Perceptual
Connection Space Illuminant     : 0.9642 1 0.82491
Profile Creator                 : Apple Computer Inc.
Profile ID                      : ca1a9582257f104d389913d5d1ea1582
Profile Description             : Display P3
Profile Copyright               : Copyright Apple Inc., 2017
Media White Point               : 0.95045 1 1.08905
Red Matrix Column               : 0.51512 0.2412 -0.00105
Green Matrix Column             : 0.29198 0.69225 0.04189
Blue Matrix Column              : 0.1571 0.06657 0.78407
Red Tone Reproduction Curve     : (Binary data 32 bytes, use -b option to extract)
Chromatic Adaptation            : 1.04788 0.02292 -0.0502 0.02959 0.99048 -0.01706 -0.00923 0.01508 0.75168
Blue Tone Reproduction Curve    : (Binary data 32 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 32 bytes, use -b option to extract)
Image Width                     : 4032
Image Height                    : 3024
Encoding Process                : Baseline DCT, Huffman coding
Bits Per Sample                 : 8
Color Components                : 3
Y Cb Cr Sub Sampling            : YCbCr4:2:0 (2 2)
Aperture                        : 1.8
Image Size                      : 4032x3024
Megapixels                      : 12.2
Run Time Since Power Up         : 8 days 21:59:36
Scale Factor To 35 mm Equivalent: 9.7
Shutter Speed                   : 1/168
Create Date                     : 2019:05:24 12:46:45.650
Date/Time Original              : 2019:05:24 12:46:45.650
Thumbnail Image                 : (Binary data 11610 bytes, use -b option to extract)
Circle Of Confusion             : 0.003 mm
Field Of View                   : 63.7 deg
Focal Length                    : 3.0 mm (35 mm equivalent: 29.0 mm)
Hyperfocal Distance             : 1.61 m
Light Value                     : 11.7

Regards,
Ralf




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