Text rotation

[knedl2007]

Hi,

i want to make a transparent png with a rotated text in it. My Code is as follows:

Code: Select all

convert ( -size 235x53 xc:none ) ( ( -size 250x50 xc:none ) ( -size 0x0 -background none -font journal.ttf -pointsize 23 -fill #111111 label:"Text Text Text" -rotate -5 ) -gravity center -composite )  -composite -depth 8 -quality 95 grouptext.png

But, whatever i try, when i rotate the text is blurred.
Without the -rotate argument, the text is sharp.

The Code above is a little bit complicated because I need the transparent canvas. Here is the essential extract:

Code: Select all

convert -background none -font journal.ttf -pointsize 23 -fill #111111 label:"Text Text Text" -rotate -5 -depth 8 -quality 95 grouptext.png

It is the same here, without the rotation it is fine, but with the rotation it is blured.

The effect is independent of the font.

thx, knedl

[anthony]

Text is blured by rotation.

Two solutions. Rotate larger text, then shrink it using resize.
That works very very well.

the alturnative is to use -distort SRT
to do it. However this is still in development but does do a better job than the default -rotate. In the next month or so I will have gotten back to its development and it will do an even better job!

Operator can also do a lot more than just rotate text, it can perspetive, or even curve, circle the text or other images. I even hope to have it do lots more still.

[knedl2007]

Thanks a lot!

nice, that it is not my fault and the hack with resizing a larger text works really fine!

[knedl2007]

by the way: could it be that the phenomenon also appears with image rotation?

[anthony]

Yes. It is caused by -rotate being defined as 3 shearing operations (for speed, not that IM is fast in this respect), rather than as a reversed pixel mapping as it is in -distort.

You can see the bluring in the enlarged view of a -rotate line...
http://imagemagick.org/Usage/distorts/#rotate_line

Compare that to using a reversed pixel mapping (-distort)
http://imagemagick.org/Usage/misc/#interpolate_line

Note that -distort will only use interpolation pixel mapping (filtering) when no minification is needed. However this may change as I am just finishing up work on resize filters (re-writing the whole resize page actually)
http://imagemagick.org/Usage/resize/
and I will be able to get back to distortion improvements.