Hi,
having loaded a Granger Rainbow image into RT, which has no ICC-profile embedded, I see a huge difference if I switch in the colour management tab from “no profile” to “embedded profile”. Shouldn’t this be the same, since no profile is embedded?
Hermann-Josef
If there is no embedded profile, the entry “embedded profile” is greyed out, so I guess there is a profile embedded.
I used EXIFtool to look for an embedded profile and could not find any (see below for a list of all tags).
Hermann-Josef
---- ExifTool ----
ExifTool Version Number : 10.02
---- File ----
File Name : GrangerRainbow.tif
Directory : .
File Size : 988 kB
File Modification Date/Time : 2003:12:05 12:52:00+01:00
File Access Date/Time : 2016:07:14 15:51:42+02:00
File Creation Date/Time : 2016:07:14 15:51:42+02:00
File Permissions : rw-rw-rw-
File Type : TIFF
File Type Extension : tif
MIME Type : image/tiff
Exif Byte Order : Big-endian (Motorola, MM)
Current IPTC Digest : 8cd1cec100db56eee4951930207e3206
---- EXIF ----
Subfile Type : Full-resolution Image
Image Width : 1600
Image Height : 1200
Bits Per Sample : 8 8 8
Compression : Adobe Deflate
Photometric Interpretation : RGB
Strip Offsets : (Binary data 40 bytes, use -b option to extract)
Samples Per Pixel : 3
Rows Per Strip : 218
Strip Byte Counts : (Binary data 40 bytes, use -b option to extract)
X Resolution : 72
Y Resolution : 72
Planar Configuration : Chunky
Resolution Unit : inches
Software : Adobe Photoshop CS Macintosh
Modify Date : 2003:12:05 13:51:56
Predictor : Horizontal differencing
Color Space : Uncalibrated
Exif Image Width : 1600
Exif Image Height : 1200
---- XMP ----
XMP Toolkit : XMP toolkit 3.0-28, framework 1.6
About : uuid:5ca3f9d3-28bc-11d8-811d-a3d7c0d93fc2
Color Space : Uncalibrated
Exif Image Width : 1600
Exif Image Height : 1200
History :
X Resolution : 72
Y Resolution : 72
Resolution Unit : inches
Create Date : 2003:12:05 13:51:56-07:00
Modify Date : 2003:12:05 13:51:56-07:00
Metadata Date : 2003:12:05 13:51:56-07:00
Creator Tool : Adobe Photoshop CS Macintosh
Derived From Instance ID : uuid:4fa2890a-28bc-11d8-811d-a3d7c0d93fc2
Derived From Document ID : adobe:docid:photoshop:4fa28909-28bc-11d8-811d-a3d7c0d93fc2
Document ID : adobe:docid:photoshop:5ca3f9d2-28bc-11d8-811d-a3d7c0d93fc2
Format : image/tiff
---- IPTC ----
Application Record Version : 2
Application Record Version : 2
---- Photoshop ----
IPTC Digest : 460cf28926b856dab09c01a1b0a79077
X Resolution : 72
Displayed Units X : inches
Y Resolution : 72
Displayed Units Y : inches
Global Angle : 120
Global Altitude : 30
Copyright Flag : False
---- Composite ----
Image Size : 1600x1200
Megapixels : 1.9
RT assumes sRGB and sRGB gamma when no icc profile is embedded … which is correct for 99% of such files.
The “no_profile” option assumes gamma = 1.0 and so only renders “correctly” files encoded with linear gamma … it’s main use is for RAW files.
Thanks for the explanation.
Hermann-Josef