GraphicsMagick - Identify and remove attached color profile - imagemagick

Question

I have some tiff images that have an embedded color profile (the example one is Canon EOS-1Ds flash).
When I convert them to jpeg (gm convert source.tif target.jpeg) the resulting jpeg colours are distorted in browsers (Chrome,Firefox, but not IE) but not in system image viewers.
If I open the source in GIMP Image Editor, and change the colour profile to sRGB, then the image from the above convert command displays correctly in browsers.
So I have this question:
How can I identify the fact that an image has an embedded color
profile using graphicsmagick?
It looks like with this command the profile is removed:
mogrify +profile '*' -define jpeg:preserve-settings
Here is the output from gm identify -verbose source.tif
Image: Di 2007-1337.tif
Format: TIFF (Tagged Image File Format)
Geometry: 4053x2257
Class: DirectClass
Type: true color
Depth: 8 bits-per-pixel component
Channel Depths:
Red: 8 bits
Green: 8 bits
Blue: 8 bits
Channel Statistics:
Red:
Minimum: 0.00 (0.0000)
Maximum: 255.00 (1.0000)
Mean: 135.75 (0.5324)
Standard Deviation: 72.49 (0.2843)
Green:
Minimum: 0.00 (0.0000)
Maximum: 255.00 (1.0000)
Mean: 129.79 (0.5090)
Standard Deviation: 72.87 (0.2858)
Blue:
Minimum: 0.00 (0.0000)
Maximum: 255.00 (1.0000)
Mean: 125.43 (0.4919)
Standard Deviation: 73.42 (0.2879)
Resolution: 400x400 pixels/inch
Filesize: 26.4M
Interlace: No
Orientation: Unknown
Background Color: white
Border Color: #DFDFDF
Matte Color: #BDBDBD
Compose: Over
Dispose: Undefined
Iterations: 0
Compression: No
Signature: bec78e9402b39f6f5539a640715270a651a39c2238846fa42f37c1c7d99af747
Profile-color: 219244 bytes
Profile-iptc: 4358 bytes
unknown:
Byline:
Rod
Source:
Rod
Created Date:
20061006
Created Time:
110014+0000
Originating Program:
Capture One PRO
Program Version:
3.7.1
unknown:
0x00000000: ffffff5c 2c3bff65 2dffff39 ffffff55 ff5bff27 ----\,;-e---9---U-[-
0x00000014: ffffffff ff7affff ffffff48 103a29ff ff17ff58 '-----z-----H-:)----
0x00000028: ff616363 3dffffff ffffffff ff777a63 6537ff19 X-acc=--------wzce7-
0x0000003c: ffffffff 3c57ffff ff3c6674 ffff5f67 ff71ffff -----<W---<
0x00000050: 74ffff5f 67ff71ff ff00 ft--_
Tainted: False
User Time: 0.030u
Elapsed Time: 0:01
Pixels Per Second: 290.8M
The converted image from the following, is broken within OS image viewers as well:
Format: TIFF (Tagged Image File Format)
Geometry: 4992x3328
Class: DirectClass
Type: true color
Depth: 8 bits-per-pixel component
Channel Depths:
Red: 8 bits
Green: 8 bits
Blue: 8 bits
Channel Statistics:
Red:
Minimum: 0.00 (0.0000)
Maximum: 255.00 (1.0000)
Mean: 213.55 (0.8374)
Standard Deviation: 57.03 (0.2237)
Green:
Minimum: 0.00 (0.0000)
Maximum: 255.00 (1.0000)
Mean: 40.76 (0.1598)
Standard Deviation: 92.06 (0.3610)
Blue:
Minimum: 0.00 (0.0000)
Maximum: 255.00 (1.0000)
Mean: 161.49 (0.6333)
Standard Deviation: 121.23 (0.4754)
Resolution: 300x300 pixels/inch
Filesize: 47.6M
Interlace: No
Orientation: TopLeft
Background Color: white
Border Color: #DFDFDF
Matte Color: #BDBDBD
Compose: Over
Dispose: Undefined
Iterations: 0
Compression: No
Artist: Gary
Timestamp: 2006:11:12 12:35:12
Make: Canon
Model: Canon EOS-1Ds Mark II
Software: Adobe Photoshop CS2 Macintosh
Signature: 1b26f2c2122ea6aa391a40c7eb885d0da120x8e9x5bd7ce0dc7cc9038ba99737
Profile-iptc: 12926 bytes
unknown:
Byline:
Gary Ombler
Originating Program:
Capture One PRO
Program Version:
3.7.3
unknown:
#Q�$�'���߸︥�[��Rҝ5��n�b����h�
Profile-XMP: 17293 bytes
Tainted: False
User Time: 0.140u
Elapsed Time: 0:01
Pixels Per Second: 45.3M

Answer 1

gm identify -verbose *.tif | egrep -a '^Image|Profile-'
This will print all matching filenames, followed by the profiles for those files that have them. This would at least let you scan a directory at a time and try to figure out why some files are problematic.

Answer 2

Perhaps you may force the colorspace to RGB:
gm convert +profile "*" -colorspace RGB source destination