Font Hinting
Everything Fonts on 2016-08-26 11:22:12What is font hinting?
There are three key concepts you need to know about imporving the quality of font rendering.
- anti-aliasing
- sub-pixel rendering
- hinting
Each of the above technique helps the rendering engine display the fonts more crisply esp. when the fonts are scaled.
Font hinting is the use of mathematical instructions to adjust the display of an outline font so that it lines up with a rasterized grid. At low screen resolutions, hinting is critical for producing clear, legible text. It can be accompanied by antialiasing and (on liquid crystal displays) subpixel rendering for further clarity. See anti-aliasing for more discusson on smooth rendering of fonts on the screen.
Where is it used?
Font hinting is used in outline fonts.
I'm not an engineer type, can you explain it again?
Unlike bitmap font format, outline font format has unlimited resolution for the glyphs. If you make the font size hundred times as big, it is just accurate as if it it were hundred times as small. Unfortunately we need to use the font in either a digital display or in a paper. That means we need to transfer the character outline to a computer monitor or a sheet of paper through a device called a raster image processor (RIP). The RIP builds the image of the character out of lots of individual pixels. A pixel is small dot either on a paper or on a screen.
The problem is, a pixel has physical size and can be displayed / printed only as either black or white. Look at a sheet of graph paper. Rows and columns of little squares (pixels). Draw a large `O' in the middle of the graph paper. Darken in all the squares touched by the O. Do the darkened squares form a letter that looks like the O you drew? This is the problem with low resolution (300 dpi). Which pixels do you turn on and which do you leave off to most accurately reproduce the character?
That is it! In very simple terms Font hinting tells RIP which pixels to turn on and to leave off to most accurately reproduce the character.