Two things. Picture to ASCII turns a photo, logo or drawing into characters: each character stands for a small block of the picture, a dense character such as @ for dark areas and a sparse one such as a dot or a space for light areas. Choose the width in characters, the character set (a detailed 70-level ramp, a classic 10-level ramp, Unicode blocks █▓▒░, or two tones), and adjust contrast, brightness and mid-tones. Keep the picture's colours for the HTML and PNG downloads. Text banner draws what you type in large letters made of characters, with a small built-in font, for README files, terminal splash screens and code comments. Copy the result or save it as text, a PNG picture or a coloured web page. The picture stays on your device.
How a picture becomes characters
- The picture is divided into a grid of cells, one per character. Characters are about twice as tall as they are wide, so a 100-column rendering of a square picture has about 50 rows; the "character shape" control changes that if your font differs.
- Each cell's brightness is the average of its pixels in linear light. Screen values (sRGB) are gamma-encoded, so averaging them directly makes fine detail look too dark: a cell half black and half white averages 127.5 in sRGB, but it gives off half the light of white, which the eye sees as a light grey.
- That light is converted to perceptual lightness (CIE L*, 0 to 100), so equal steps along the character ramp look like equal steps in brightness.
- Contrast, brightness and the mid-tone (gamma) controls adjust the value, and it is mapped onto the ramp: black to the densest character, white to the sparsest.
The article on character ramps and gamma works through these numbers with examples.
Text banners
Type up to 80 characters. The built-in font has letters A to Z, digits and common punctuation, five rows tall; accents are removed (Vietnamese "Xin chào" becomes XIN CHAO) and anything else is drawn as "?". Draw it with # signs, full blocks, dark shade, or each letter with itself, at one, two or three times the size. Paste the result into a place that uses a monospace font, or it will not line up.
Good to know
Results depend on the font they are shown in: ASCII art only lines up in a monospace font, and the character density of @ or # differs slightly between fonts. The PNG download draws the art in your system's monospace font. The picture is read from a copy of at most 1,200 pixels on its longest side, more than enough for 300 columns. For text tools, see the text toolkit; for exact colours from the picture, the image colour picker.
