reading-notes

Images

There are several things to consider when selecting and preparing images for your site, but taking time to get them right will make it look more attractive and professional. In this chapter you will learn how to:

● Include an image in your web pages using HTML

● Pick which image format to use

● Show an image at the right size

● Optimize an image for use on the web to make pages load faster

If you are building a site from scratch, it is good practice to create a folder for all of the images the site uses.

Three Rules for Creating Images

1-Save images in the right format

2-Save images at the right size

3-Use the correct resolution

Image Dimensions

The images you use on your website should be saved at the same width and height that you want them to appear on the page

Cropping Images

When cropping images it is important not to lose valuable information. It is best to source images that are the correct shape if possible

Color

The color property allows you to specify the color of text inside an element. You can specify any color in CSS in one of three ways:

1- rgb values : Values for red, green, and blue are expressed as numbers between 0 and 255.

2- hex codes : Hex values represent values for red, green, and blue in hexadecimal code. hsl, hsla

3- color names : Colors are represented by predefined names. However, they are very limited in number.There are 147 color names

**opacity :

CSS3 introduces the opacity property which allows you to specify the opacity of an element and any of its child elements. The value is a number between 0.0 and 1.0 (so a value of 0.5 is 50% opacity and 0.15 is 15% opacity).**

Text

The properties that allow you to control the appearance of text can be split into two groups:

● Those that directly affect the font and its appearance (including the typeface, whether it is regular, bold or italic, and the size of the text)

● Those that would have the same effect on text no matter what font you were using (including the color of text and the spacing between words and letters)

Specifying Typefaces

1- font-family

The font-family property allows you to specify the typeface that should be used for any text inside the element(s) to which a CSS rule applies.

2- font-size

The font-size property enables you to specify a size for the font

3- font-face

font-face allows you to use a font, even if it is not installed on the computer of the person browsing, by allowing you to specify a path to a copy of the font, which will be downloaded if it is not on the user’s machine.

@font-face {

font-family: ‘ChunkFiveRegular’;

src: url(‘fonts/chunkfive.eot’);}

4- font-weight

The font-weight property allows you to create bold text. There are two values that this property commonly takes:

-normal

This causes text to appear at a normal weight.

-bold

This causes text to appear bold.

5- font-style

-normal

This causes text to appear in a normal style (as opposed to italic or oblique).

-italic

This causes text to appear italic.

-oblique

This causes text to appear oblique.

6- UpperCase & LowerCase

7- Underline & Strike

8- Leading (line-height)

Leading (pronounced ledding) is a term typographers use for the vertical space between lines of text

9- letter-spacing, word-spacing

10- text-align and vertical-align

11- text-indent

12- text-shadow

13- :first-letter, :first-line

14- :hover, :active, :focus

Attribute Selectors Ref. - Page 292

JPEG vs PNG vs GIF

JPEG

images don’t support transparency and are hence not usable for such cases and can support around 16 million colours. This is what makes them suitable for storing images of natural scenes.

PNG

images mainly have two modes — PNG8 and PNG24. PNG8 can support upto 256 colours whereas PNG24 can handle upto 16 million colours like a JPEG imagea and mages support transparency in two ways.

GIF

images support transparency by declaring a single colour in the colour palette as transparent (index transparency) and GIF images are limited to 256 colours