As Andreas note we are rather close towards Calligra 2.4 which will be the very first release of the Calligra Suite.

Our pretty cool Calligra Quality Dashboard lists 11 remaining release-critical blocker bugs that still need to be fixed till then.

After day 0 on friday which I missed and day 1 on saturday where I joined the Calligra 2011 sprint in Berlin in the evening after a longer journay the last day of the sprint, day 2, is coming to and end.

This weekend there will be the Calligra spring 2011 in Berlin in KDAB's office in berlin where I usually work and play kicker and table tennis all of the week. The irony is that I very likely will not make it to the sprint. I was visiting some friends in Koh Tao and I am now caught in a heavy storm in Koh Samui since more then a week now. My fly was canceled and the airport was closed, my visa was running out and cash problems raised up.

Though this entry will be the last one about my GSoC, it certainly won't be the last one about my work on Krita or even on its new Transformation Tool. It was a great summer, I had a lot of fun working on this project. It was all the more stimulating so as I could follow the progress of the other GSoC students working for Krita. Everyone did such an incredible job, it gave me the envy and the energy to complete my project and make it as it is.

I spent the past 10 days working on image warping. It wasn't easy, but I think most of the work is done !

Since I had absolutely no idea concerning the algorithm, and wasn't even sure what I wanted to do - I only knew I wanted to add an "image deformation" functionality to the tool -, I began searching randomly on the web. I eventually came across a nice paper entitled Image Deformation Using Moving Least Square.

It's been two weeks since my last blog entry, so I thought it was time I gave an update about my work.

The next step was to add perspective transformation to the tool, and the least I can say is it wasn't easy.
First thing is it took me some time to find the formulas and good values to create a good perspective effect, and then to obtain the same one with Qt.

Hello everyone !

Last week I finally decided to spend some time on the UI of the tool, and you will see on this screencast that there has been some changes !

After correcting a small bug I introduced in the transform worker when adding shearing, I designed the Tool Options widget. I decided not to keep the mockup I made for my GSoC application, because I realized something vertical was more appropriate for Krita.

Hi guys,

Maybe it's a bit late to talk about what I did last week, but anyway :

After fixing some bugs in the transformation tool, I decided to add the possibility for the user to change the center of rotation.
It was a bit tricky, because I wanted to express this rotation (around the current center) as a composition of a rotation around the original center of the selection and a translation (which is possible). Consequently, a succession of rotations around different center can be reduced to only 1 rotation around the original center and 1 translation.

This is my first blog entry about my GSoC project for Krita.

Because i was busy doing a school project until June 11, i actually began working on the transformation tool last week.

The aim was to rewrite most parts of the old transformation tools, in order to continue the project on a solid base, and with my own code, to make the job easier. I also wanted to make the tool perform transformations in real time, not just when the user releases the mouse button.

This weekend have so far resulted in 5 commits on Krita. In particular on the scaling stuff. Krita has for way too long had some outstanding quality issues with scaling. The edge pixels were transparent and the images themselves were too blurry.

Just see this page from over 2 years ago: http://gis-blog.leonde.de/index.php/2006/11/10/scaling-algorithms-in-krita/

Well this weekend was the day to end the misery. I started with implementing bicubic filtering which removed the blur, and went on to fix the transparent edges. The main part of the bug was actually a simplerounding error, but looking into the issue i also found that the filter weights were being applied wrongly, so I fixed that too.

But that was not all. The code for mixing of colors couldn't handle negative weights which gave some weird colors popping up weird places in the images. After some debugging all it took to fix it was clamping the resulting rgb values to not be negative.

After that I fixed some regressions regarding progress feedback while scaling, and right now I've bugged Sven Langkamp to help me with the selection stuff in the transform tool. Funny thing is I was his mentor on a GSoC about selections two years ago and now he is the one who helps me :)

Anyway here are the results so judge for yourself (I've used the same original as in the blog I referred to above and bicubic filters in all cases).

Photoshop 7:

Gimp 2.6.1:

Krita (trunk):

I'm quite pleased as it looks very similar to photoshop.