Tuesday, 7 June 2016

GIMP Bucket Fill colours not changing

I had a problem that has cropped up occasionally before but I never bothered investigating.  I needed to make a multi coloured logo into an all white and an all black logo to be printed on dark and light shirts respectively (screened or DTG in white ink and black ink).

So I converted the logo into a white PNG with a transparent background.  The quickest way to do this is to use:
Image > Mode> Indexed.     That should convert the whole thing to black, then to get my white logo I just use Color> Invert.

But of course, I had to show what it would look like on a coloured background.

When I used the GIMP bucket Fill tool, and selected a nice blue background colour, the fill kept putting the default black BG colour into the transparent area.  Swapping to FG just filled the transparent area with the default white.  Nothing would make the tool fill with the blue I chose.

Then I remembered.  I was working in 'Indexed Mode' which is how I converted the coloured logo to pure white in the first place!

The fix was simple:

Image> Mode> RGB

Then the Bucket Fill tool allwed me to fill the transparent areas with Blue.

Friday, 3 June 2016

The most important NEW FEATURE for Raspberry Pi - backup your SD card

While I agree that the Raspberry Pi is basically a toy computer, that is only because of a few design limitations imposed by the builders sticking to the original low budget ideals.

The greatest of these is the lack of Flash memory and the lack of a swap partition somewhere fast.  Everything is done within the rather slow limits of a micro SD card.  And from time to time the Raspberry Pi will simply lose its ability to work due to corruption of the SD card.

The latest update of the Raspbian 'Jessie' operating system goes a long way to making that easier to live with.  Under Accessories in the Menu is an option called 'SD Card Copier'.

This tool is a little like the Linux 'dd' command, except that it is graphical and semi automatic.  All you need to do is insert a micro SD card in a suitable card reader in one of your USB ports, choose that card as the destination to write to and hit start.

It defaults to choosing an MMC (which generally implies an SD card) so as long as you don;t have another SD or micro SD card attached you are unlikely to make a mess.  The process takes as long as writing a disk image using dd, but you just leave the Pi to do it along and don;t touch anything until you see the job completed popup.

The wonderful thing about this is that I can install a heap of new Add Ons to KODI for example, then backup the whole thing to a spare card.  Or I can do an update or a dist-upgrade and backup to a spare card.  All your current settings including wallpaper, special changes to config files, everythign is mirrored to the copied card.  So if something goes wrong, all you lose is whatever you added or any documents and stuff since the last backup.

It takes away all the guesswork and the worry about possibly corrupting your micro SD card.