Archive for Graphics

Changing from Nouveau to Nvidia Graphics Drivers on Linux Mint Debian Edition 64-bit

One way of doing this is to go to the Nvidia website and download the latest file from the relevant page on there. Then, the next stage is to restart your PC and choose rescue mode instead of the more usual graphical option. This drops you onto a command shell that is requesting your root password. Once this is done, you can move onto the next stage of the exercise. Migrate to the directory where the *.run file is located and issuing a command similar to the following:

bash NVIDIA-Linux-x86_64-295.40.run

The above was the latest file available at the time of writing so the name may have changed by the time that you read this. If the executable asks to modify your X configuration file, I believe that the best course is to let it do that. Editing it yourself or running nvidia-xconfig are alternative approaches if you so prefer.

Proprietary Nvidia drivers are included the repositories for Linux Mint Debian Edition so that may be a better course of action since you will get updates through normal system update channels. Then, the course of action is to start by issuing the following installation comands:

sudo apt-get install module-assistant
sudo apt-get install nvidia-kernel-common
sudo apt-get install nvidia-glx
sudo apt-get install kernel-source-NVIDIA
sudo apt-get install nvidia-xconfig

Once those have completed, issuing the following in turn will complete the job ahead of a reboot:

sudo m-a a-i nvidia
sudo modprobe nvidia
sudo nvidia-xconfig

If you reboot before running the above like I did, you will get a black screen with a flashing cursor instead of a full desktop because X failed to load. Then, the remedy is to reboot the machine and choose the rescue mode option, provide the root password and issue the three commands (at this point, the sudo prefix can be dropped because it’s unneeded) then. Another reboot will see order restored and the new driver in place. Running the following at that point will do a check on things as will be the general appearance of everything:

glxinfo | grep render

Why the manual step?

One of the consequences of buying a new camera is that your current photo processing software may not be fully equipped for the job of handling the images that it creates. This is a particular issue with raw image files and Adobe Photoshop Elements 5 was unable to completely handle DNG files made with my Pentax K10D until I upgraded to version 7. Yes, I do realise that upgrading camera should been in order but I only lost the white balance adjustments so I could with things as they until upgrading gained a more compelling case.

As things stood, Elements 7 was unable to import CR2 files from my Canon PowerShot G11 into the Organiser so it was off to the appropriate page on the Adobe website for a Camera Raw updater. I picked up the latest release of Camera Raw (5.6 at the time of writing) even though it was found in the Elements 8 category (don’t be put by this because release notes address the version compatibility question more extensively). Strangely, the updater doesn’t complete everything because you still need to copy Camera Raw.8bi from the zip archive and backup the original. Quite why this couldn’t have been more automated, even with user prompts for file names and locations, is beyond me but that is how it is. However, once all was in place, CR2 files were handled by Elements without missing a beat.

Converting from CGM to Postscript

On thing that I recently had to investigate was the possibility of converting CGM vector graphics files into Postscript and from there into PDF. Having used ImageMagick for converting images before, that was an obvious option. However, that cannot process CGM files on its own and needs a delegate or helper application as well. This is the case with raw digital camera files too with UFRaw being the program chosen. For CGM images, the more obscure RALCGM is what’s needed and tracking it down is a bit of an art. The history is that it was developed at the U.K.’s Rutherford Appleton Laboratory but it seems that it was left go off into the wilderness rather than someone keeping an eye on things. With that in mind, here are the installation packages for Windows and Linux (RPM):

Windows Installer

Linux RPM

RALCGM is a handy command line tool that can covert from CGM to Postscript on its own without any need for ImageMagick at all. From what I have seen, fonts on graphical output may look greyer than black but it otherwise does its job well. However, considering that it is a freely available tool, one cannot complain too much. There are other packages for doing vector to raster conversion and the ones that I have seen do have GUI‘s but the freedom to look at for cost software wasn’t mine to have. The required command looks something like the following:

ralcgm -d PS -oL test.cgm test.ps

The switch -d PS uses the software’s Postscript driver and -oL specifies landscape orientation. If you want to find out more, here’s a PDF rendition of the help file that comes with the thing:

RALCGM Documentation

A certain lack of speed

A little while, I encountered a problem with ImageMagick processing DNG files in Ubuntu 9.04. Not realising that I could solve me own problem by editing a file named delegates.xml, I took to getting a Debian VM to do the legwork for me. That’s where you’ll find all the commands used when helper software is used by ImageMagick to help it on its way. On its own, ImageMagick cannot deal with DNG files so the command line variant of UFRaw (itself a front end for DCRaw) is used to create a PNM file that ImageMagick can handle. The problem a few months back was that the command in delegates.xml wasn’t appropriate for a newer version of UFRaw and I got it into my head that things like this were hard-wired into ImageMagick. Now, I know better and admit my error.

With 9.1o, it seems that the command in delegates.xml has been corrected but another issue had raised its head. UFRaw 0.15, it seems, isn’t the speediest when it comes to creating PNM files and, while my raw file processing script works after a spot of modification to deal with changes in output from the identify command used, it takes far too long to run. GIMP also uses UFRaw so I wonder if the same problem has surfaced there too but it has been noticed by the Debian team and they have a package for version 0.16 of the software in their unstable branch that looks as if it has sorted the speed issue. However, I am seeing that 0.15 is in the testing branch so I’d be tempted to stick with Lenny (5.x) if any successor turns out to have slower DNG file handling with ImageMagick and UFRaw. In my estimation, 0.13 does what I need so why go for a newer release if it turns out ot be slower?

8?

It now seems that we have a new version of Photoshop Elements from Adobe for every year unless you’re a Mac user. Version 7 convinced me to splash out and that gained me Camera Raw recognition of my Pentax K10D along with subtly enhanced image processing power that I have been putting to good use to get more pleasing results than I ever got before. What can be achieved by using levels, curves and the shadow/highlight adjustment tool for exposure correction has amazed me recently. Quick selection functionality has allowed me to treat skies differently from everything else in landscape photos, a flexible graduated filter if you like. It seems to work on Windows 7 along with Vista and XP so I plan to stick with it for a while yet. As you may have gathered from this, it would take some convincing to make me upgrade and, for me, version 8 doesn’t reach that mark. All in all, it seems that it is a way of giving Mac users a new release with added goodness after having to stay with 6 for so long; yes, there are new features like autotagging in the image organiser but they just don’t grab me. Given that they already have Aperture from Apple and Windows users seem to get more releases, it’s a wonder that any Mac user would toy with Elements anyway. Maybe, that’s Adobe’s suspicion too.

Enabling DVD playback in Ubuntu 9.04

This information is scattered about the web but I decided to collect something together in one place in case it helps anyone else. Here are two commands that appeared to do the deed for me:

sudo apt-get install ubuntu-restricted-extras totem-xine libxine1-ffmpeg libdvdread4

sudo /usr/share/doc/libdvdread4/install-css.sh

The libdvdread piece is what sorts out encrypted disks and needs a two stage installation, hence the second command. For non-encrypted disks, ubuntu-restricted-extras might be all that’s needed if my experience is typical. Taking things further, Wim Wenders’ Buena Vista Social Club (Region 2 disk) worked when I tried it too. In the interests of completeness, I tried the command combination on a virgin 9.04 installation with restricted and multiverse repositories enabled. Along the way, I spied a whole raft of helper components being set in place and things worked like I would have expected with the aforementioned DVD afterwards. As with anything related to computing, your mileage may vary and, for more information, you can take a look here.

  • As is commonly the case with places like these, all the views that you find expressed on here in postings and articles are mine alone and not those of any organisation with which I have any association, through work or otherwise. With regards to any comments left on the site, I reserve the right to reject any that are inappropriate. Otherwise, whatever is said is the sole responsibility of whoever is leaving the comment.