Episode 079: Shoot the Screen!

Download the Video!
Download the companion file! (…if there is one…. ;-) )

79This is just a short show to catch up on my missed show on Tuesday. I’ll look a tiny bit behind the math in the convolution matrix with a spreadsheet model of a single row of pixels.

And I’ll show you an often overlooked feature of GIMP – the screenshot. It’s way more flexible than just pressing “PrntScrn”. It even stores the mouse pointer on a different layer.

The companion file contains also the images for the next show. I was too lazy to un- and repack that again. ;-)

The TOC

00:19 Welcome
00:33 Greetings to Norman
01:10 Understanding the Convolution Matrix
03:48 – Sharpening
05:18 – Blurring
06:43 The Forum
08:16 Screen shots using Gimp
13:03 the End
TOC made by paynekj

Creative Commons License This work is licensed under a
Creative Commons Attribution-Share Alike 2.0 Germany License.

8 thoughts on “Episode 079: Shoot the Screen!

  1. I think it should be pointed out that the Windows version of screen capture doesn’t have the same options – it only has capture a single window, capture the whole screen, and a delay – no options for window decoration and mouse pointer.

  2. Good and helpful explanation Rolf!

    Unsharp mask gives us three options.
    Radial, amount and threshold. Can you explain a little deeper how that works?
    Using the spreadsheet I suppose that the threshold is an if…then rule
    How does it work using amount and radius.
    - By default radius is 5. Does that mean 5 pixels width?
    - By default the amount is 0,5. Does that mean 256 multiplied by 0,50?
    Usually approx 0,15 – 0,25 is enough.

    By the way. You use openoffice 2.4. I’m, 3.x user, curious what this will bring.

    Our Mission
    “Create a User Interface so that OpenOffice.org becomes the users’ choice
    not only out of need, but also out of desire”

    http://wiki.services.openoffice.org/wiki/Renaissance

  3. Ger, this was a catchup on the Convolution Matrix Filter, not on unsharp mask. That is way more complicated. ;-) But I’ll try to go onto that.

    I’ll wait with OO 3 until Ubuntu packs it on my machine – or is it so much advanced that I should take the risk of breaking packages?

  4. Well, I tried OO 3.0 and it was working well. But the package manager always thought that OO is not installed and wanted to install 2.4 again during updates. I always had to deselect it manually…

  5. Rolf, about OOo. To me it’s a kind of kick to have the newest options.
    Rarely/Sometimes I do receive a document in a new format. So I can open or ask sender to re-save in another format.
    A student version of microsoft office 2007 costs me approx 150euro. OOo is for free and enables me to save in pdf. So sender will always see what I saw on screen and will can’t 1,2,3 change my document.

    About CMF (oke no unsharp mask). It’s has my intention. It fascinates me.

  6. Here’s a TOC:

    Episode 079: Shoot the Screen!
    00:19 Welcome
    00:33 Greetings to Norman
    01:10 Understanding the Convolution Matrix
    03:48 – Sharpening
    05:18 – Blurring
    06:43 The Forum
    08:16 Screen shots using Gimp
    13:03 the End

  7. Hi,
    the Gimp screenshot tool seems to be very handy, but I think only, if you want to capture Gimp itself, because normally my Gimp window fills almost my whole screen, so if you want to capture another window, you’d have to resize/move the gimp window first (and when capturing the whole screen, the Gimp window will be visible, unless you minimize it during the countdown), right? A function like “hide Gimp while taking the screenshot” would be really cool.

    Btw. on the mac the whole screenshot thing doesn’t work, because of the X11 environment, Gimp runs in. Taking screenshots of gimp windows will create a black image and other windows (which are not running in the X11 environment) simply don’t react to the function.

Anything to add from your side of the computer?