blurry images after scaling down
On Nov 28, 2007 10:04 AM, ChadDavis wrote:
I'm down scaling some tif images. These images are created with a graphics
software for making diagrams and the like. Geometric shapes and text
mostly. When I open the tif in Gimp they are perfectly crisp. When I scale
the image down in size, it becomes slightly blurry, even when opting for the
"best" cubic algorithm.
Is this to be expected?
Yes, Gimp deals with pixels, not vectors. when you scale down, you
reduce the number of pixels that are used to represent the image.
If your graphics are vector based and you want to keep them that way,
use a vector drawing program like Inkscape to manipulate them, not a
raster manipulation program like GIMP.
What's the best practice for preparing graphics so
that they are crisp? I thought i should make them large and that way they
would have extra resolution. But apparently scaling down is a lossy
Extra precision just means a more accurate averaging. Say you are
scaling the image down to 50% of original size.. that means that each
resultant pixel is calculated from the average of a 2x2 square of
pixels. say that 2 of these input pixels are black, and two are white,
since it is an average, each of the following produce the same result:
So, it is indeed lossy.
If you want a raster image to be maximally crisp, your best bet is to
draw it at the final size. If you want a vector image to be crisp,
your work is probably unrelated to the GIMP.