Higher-bit scans are reduced to 8 bit
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| skanlite (Ubuntu) |
Fix Released
|
Low
|
Christian Mangold | ||
Bug Description
Binary package hint: skanlite
I'm using an Epson GT-X700 scanner with Skanlite on Kubuntu 10.04. Skanlite supports the scanner, but scanning at more than 8 bit per colour doesn't work. I set up Skanlite like this:
- Scan source: Transparency Unit
- Film type: Negative film
- Scan mode: Grey
- Bit depth: 16
- Scan resolution: 600 DPI
- Focus position: Focus on glass
The scan seems to work as expected, but when it has finished I get this message:
The image data contained 16 bits per colour, but the colour depth has been truncated to 8 bits per colour.
An 8-bit PNG file is saved, instead of a 16-bit image as I requested. The message doesn't give any indication as to the cause nor the solution. If it is a matter of selecting the correct file format, you can't expect the user to know all details about PNG, BPM and all those other three-letter acronyms. If the user has selected 16-bit and a file format that doesn't support it, this should be reflected in the error message, and the message should be given *before* scanning commences.
XSane works fine with the same scanner and the same settings, and outputs 16-bit TIFF files.
ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: skanlite 0.4-kde4.4.0-1
ProcVersionSign
Uname: Linux 2.6.32-22-generic x86_64
NonfreeKernelMo
Architecture: amd64
Date: Tue Jun 1 12:06:06 2010
ExecutablePath: /usr/bin/skanlite
InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427)
ProcEnviron:
SHELL=/bin/bash
PATH=(custom, user)
LANG=en_GB.UTF-8
LANGUAGE=en_GB
SourcePackage: skanlite
XsessionErrors:
(process:1734): GLib-CRITICAL **: g_once_init_leave: assertion `initialization
(npviewer.
(npviewer.
(npviewer.
(script-fu:3188): LibGimpBase-WARNING **: script-fu: gimp_wire_read(): error
Related branches
| Sybren Stüvel (sybren-stuvel) wrote | #1 |
| Sybren Stüvel (sybren-stuvel) wrote | #2 |
| Sybren Stüvel (sybren-stuvel) wrote | #3 |
| Changed in skanlite (Ubuntu): | |
| assignee: | nobody → Christian Mangold (neversfelde) |
| status: | New → In Progress |
| Changed in skanlite (Ubuntu): | |
| importance: | Undecided → Low |
| Launchpad Janitor (janitor) wrote | #4 |
| Changed in skanlite (Ubuntu): | |
| status: | In Progress → Fix Released |
On my computer Skanlite supports the following image formats: PNG, JPG, JPEG (what's the difference with JPG?), BMP, PPM, XBM and XPM. I did some digging on Wikipedia, and it seems that none of these formats can actually hold an image with more than 8 bits per colour.
In my opinion any scanning application should at least support output to higher-bit TIFF files. PPM, XBM and XPM aren't used by any graphical designer or photographer, but TIFF is widely used.