I often find myself having to create images that serve as separator content within prints, or some simple graphic effects created with tracked, or with letters. I'm thinking of something very simple, that surely even in the old schoolbooks we were used to seeing without realizing.
Occasionally, however,, I happen to create the new image, save, and realize that the work is finished the dpi is too low Gimp because those who apply by default are 72, excellent to the web but too little for a detailed Print quality. Today we see how increase the dpi of an image we have already saved with Gimp 72 dpi, and the portarla 300 (great for Print).
To “dpi” means “Dots per inch” (Dots Per Inch). It is the amount of image information that can be rendered by an output device such as a graphic printer, a plotter, a RIP or one screen. With the DPI is expressed quantity of printed dots or displayed on a line an inch long (about 2,54 cm). Generally a higher value corresponds to a higher resolution and a better yield on sloping lines.
Start now by saying that of course the final image will smaller than the original. Much smaller than the larger the detail. It is an inverse proportion : “72” (the initial dpi) Next a “300” (s final dpi) come “x” (the measures that we will get) Next a “15cm” (the initial measures).
Let's say we have an image of 17cm of height 72dpi the proportion used will be 72 : 300 = x : 17. And the result will be 4,08cm, about a quarter of the initial value.
To change the resolution the image is enough to go on “Picture” – “Scale Image” and change the values of “Resolution x” and “Y resolution“.
It is also possible Gimp configuration saved because automatically images 300dpi. In the menu “Edit” – “Preferences” under the tab “Default Image” basterà passare da 72dpi the quality that we prefer.