images & tables. three graphic file types are supported by today's browsers: gif - graphic...
Post on 19-Dec-2015
225 views
TRANSCRIPT
Three graphic file types are supported by today's browsers:
GIF - Graphic Interchange Format JPEG - Joint Photographic Experts
Group PNG - Portable Network Graphics
Image file formats
GIF
GIF files are best used for images that have broad areas of flat color and are highly defined.
Supports transparency and animation Supports a maximum of 256 colors. Guidelines to keep GIF files small:
• Reduce the number of colors
• Crop out extra space if possible
JPG
JPEG files are best used for images that require many colors such as photographs.
JPEG has a higher compression ratio but it is a "lossy" compression (compression sacrifices some image data in reducing file size).
PNG PNG was developed as an alternative to GIF Does not yet have broad-based browser or
image editor support. Has a lot of the same features as GIF PNG also automatically adjusts graphics for
gamma correction to compensate for cross-platform differences in brightness and contrast.
Does not support animation
Inserting images on your pages: Image tag
<img src= “name and location of image file”> We usually put images in a separate folder on
the web server. The image file has a 644 permission
Example: <img src= “Images/photo.jpg”> The source attribute (src) refers to the name and
location of the image file relatively to the HTML file itself.
Image tag attributes
height: specifies the height of the image. width: specifies the width of the image. border: determines the size of the border. alt: specifies the text displayed on-screen when the
cursor is rolled over the image. Always use this! align: puts the image to the right or left of the screen. valign: align text associated with the image at the top,
middle, or bottom wrt the image.
Aligning Images
To align an image left:
<img align=“left” src=“images/myImage.gif"> Using CSS (the <style> tag):
img {float: left} Both of these will cause text to appear to the right of
the image and wrap around it.
Aligning Images
NOTE: Most browsers do not support <img align=“center”>
To align an image center: <img src=“images/whatever.gif"><p align=“center”> </p>
Image Borders
Line that appears around a picture (like a frame).
Will appear automatically when you use an image as a link.
<img border=“#”>Where # is between 0 and 99
Linking from an Image
Place the <img> tag inside the anchor tag.
<img src=“whatever.jpg"> <a href=“http://www.somewhere.com"> </a>
<html><head>
<title>Some images </title></head><body>
<img src = “Images/key.jpg"> This pic caption shows up at the bottom<br>
<img src = “Images/flowers.jpg " width=“100” height=“50”alt=“Flowers” align=“right” border=“3”>
<br>Hyperlinked picture: <a href="http://www.pixar.com/"><img src=“Images/carsPixar.jpg">
</a>
</body></html>
Example
Caption for an image
Affect image size
Add border
Image as page background
<body background = “../jpg/bgd/stucco1.jpg”> sets the background image.
Using the new standard (within <style> tag):body {background-image: url(../jpg/bgd/stucco1.jpg)}
Image Size:• A large image may only appear once (depending on
the size of the browser window)
• Smaller images will be tiled as many times as necessary to fill a page.
HTML and Colors
Colors in HTML documents are represented by a triplet of numbers, called an RGB triplet, based on their Red, Green, and Blue component. Ex: RED = (255,0,0)
HTML requires that the color values be entered as 3 two-digits hexadecimal numbers. Ex: RED = FF0000digit1 digit2 digit3 digit4 digit5 digit6
red green blue There are many online charts and references for color. Or
just click on Color Chart from our Important Documents page.
Color as attribute of Body Tag
Text color• <body text=“#000080”>
Background color• <body bgcolor=“#FFFFF0”>
New standard (within <style> tag):body {background-color: Ivory; color: Navy}
Hyperlink has 4 states:• link: unvisited links
• vlink: visited links
• hover: mouse hover over link
• alink: a hyperlink that the user is thinking of visiting (the user has moused over and depressed the mouse button on).
Hyperlink colors:
More links about Color:
HTML Colors:http://www.w3schools.com/html/html_colors.asp
HEX <-> RGB color code converter:http://www.yvg.com/twrs/RGBConverter.html
Background/Text color selectorhttp://www.imagitek.com/bcs.html?
Basic HTML Tables A table organizes data in rows and columns <table> … </table> Enclose the table structure <tr> … </tr> Table row <td> … </td> Each data cell within a row. The
smallest area of a table that can be formated.This controls the number of columns in the table.
Basic table structure<table>
<tr><td>A1</td><td>A2</td><td>A3</td>
</tr><tr>
<td>B1</td><td>B2</td><td>B3</td>
</tr></table>
A1 A2 A3
B1 B2 B3
First row
First Column
<table> attributes
border="# pixels"> Size of the border around the table
cellspacing ="# pixels"> space inserted between cells
cellpadding ="# pixels"> size of the gap between the cell text and the cell border
align ="left/right"> table is placed on the left/right and text is wrapped around the table"center"> table is placed in the center of the page. Text is not wrapped around the table
More <table> Attributes
bordercolor="color"> changes the color of the border.
bordercolordark="color">bordercolorlight="color"> creates a 3D effect for the border.
More <table> attributes
frame="box|above|below|void" …> controls which side of the table has borders
<table>,<td>,<th> attributes
width="pixels" or "%"> table/cell width in pixels or as % of the page/table.
height="pixels" or "%"> Same as above. bgcolor="color"> Change the table/cell
background color. background=“pic.jpg”> Tiles a picture as
a background.
Question
Given a table specified with:<table border="3" cellspacing="0" cellpadding="3" width="100%"> with the first three cells in the first row coded as:<td width="40%">
<th width="20%">9 A.M.<th width="10%">12 P.M.
What is the width of the last column in the above table?
Cell attributes (<td>,<th>)
colspan="#" this cell spans across # columns.
rowspan="#" this cell spans over # rows.
align=
valign=
"left/right"> text in the cell is aligned left/right.
"center"> text in the cell is centered."top/bottom"> text in the cell is aligned top/bottom.
"middle"> text in the cell is aligned with the middle of the cell.
Summary - Table Level Attributes
<table
width="n" pixels or "n%" percentage
align="left", "center", "right“
bgcolor="hex value“
border="pixels“
bordercolor="hex value“
cellspacing="pixels“
cellpadding="pixels" >
</table>
Summary - Row Level Attributes
<tr align="left", "center", "right“ valign="top", "bottom", "middle"
bgcolor="hex value” ></tr>
Summary - Cell Level Attributes
<td align="left", "center", "right“ valign="top", "bottom", "middle“ bgcolor="hex value“ height="n" pixels or "n%" percentage width="n" pixels or "n%" percentage rowspan="n" rows to span colspan="n" columns to span ></td>
Tables are very commonly used for webpage design layout
To display content in newspaper-like columns or separates the page in different topical areas.
Start with the outer table and work your way in using nested tables.
Add background color to visually separate column.
Add cell padding to avoid crowding. Use row spanning to vary the starting point of
articles.