jargon explained
For some, the world of digital photography and the
creation of a web site can be daunting and confusing.
We have put together a few phrases and words that are regularly used in the
capture of images to be used on the internet.
We hope you will find them helpful
and beneficial in your use of digital images on your website.
Pixels
Digital cameras store images as a collection of tiny dots called pixels (picture
elements). The more pixels, the better the quality. The number of pixels captured
by the image sensor is known as resolution.
Resolution refers to the number of pixels packed into a certain area. Megapixel cameras capture one million
pixels or more. Pixels on a computer
screen are the small dots that make up the image on your computer screen.
Currently, most PC monitors are set at a pixel resolution of 640x480 which
means that the image across the entire screen is 640 pixels wide and 480 pixels
high. People with larger monitors and more powerful computers may reset the
resolution to 800x600, 1024x768, or even higher. If a graphic on your web
page is wider than 640 pixels, users with 640x480 screens will have to scroll
back and forth to see all of it which can be really annoying when trying to
see all of the image. When the image is displayed too large or at a low resolution
the image becomes pixelated (this image has been done purposely to show the
effect).
Resolution
Resolution refers to the number of pixels in an image. Resolution is sometimes
identified by the width and height of the image as well as the total number
of pixels in the image. For example, an image that is 2048 pixels wide and
1536 pixels high contains 3,145,728 pixels (or 3.1 Megapixels). You could
call it a 2048 x 1536 or a 3.1 Megapixel image. As the megapixels in the pickup
device in your camera increase so does the possible maximum size image you
can produce.
This means that a 5 megapixel camera is capable of capturing
a larger image than a 3 megapixel camera. The higher the resolution and number
of pixels increases the file size. The ideal resolution for an image to be
displayed on a website is either 72 pixels per square inch (psi) or 96psi.
Keeping the images at these resolutions
allow the image to be loaded onto the web page faster allowing the viewer
to see the image immediately, rather than waiting for the image to load. Although
some image quality is sacrificed for the smaller resolution, it will not be
detremental for the purpose of viewing on a computer. The image displayed
here is 100 pixels by 100 pixels, set at a resolution of 72 pixels per square
inch. This size image is often refred to as a thumbnail.
JPEG's & GIFS's
JPEG is a digital image file format designed for maximal image compression.
JPEG uses "lossy" compression in such a way that, when the image is decompressed,
the human eye won't find the loss too obvious. The amount of compression is
variable and the extent to which an image may be compressed without too much
degradation depends partly on the image and partly on its use.
A GIF is a bitmap file format often used on the World Wide Web. The color
limitation makes the GIF format unsuitable for reproducing color photographs
and other images with continuous color, but it is well-suited for simpler
images such as graphics or logos with solid areas of color. An animated GIF
is a series of individual GIF frames joined together to create an animation.
It is perhaps the easiest way to create and view simple animations.
Resizing
Once an image has been captured, it will be saved on the memory card as a
RAW image in a large file size. This file size is normally in a resolution
of 300 pixels per square inch (psi). This is too large to display on a website
or send in an e-mail. (Remember your screen resolution could be only 640 pixels
wide, therefore if you have several images on the web page they will not be
displayed correctly and could take longer than usual to load on the web page,
frustrating potential customers). 
Resizing the image involves the use of photo editing software to a size that will not lose quality and
can be easily viewed and sent on the web. Here we have two images, the smaller
thumbnail is set at 100x100 psi (pixels per square inch) and the larger image
is set at 200x200psi. The smaller image is as a result of re-sizing the larger
image.
Post production
Here at lightBox solutions we carry out all post production work using the
latest photo editing software, ensuring images are sharp, void of noticeable
blemishes, marks or scratches. Other post production work we can carry out includes the
cutting out of an image from a background and placing it on a different background.
We also carry out any necessary lighting and shadow changes to the image to
ensure the image looks its best for uploading onto the internet.
Cut-out
Most products displayed for sale on the internet are shown on a bright white
background, so to achieve this look the product is cut-out using photo editing
software and placed onto a bright white background.
Where a picture of a product is taken in a non studio environment, it usually
has the appearance of an amateur attempt and the image will not look professional
or aesthetic. Cut-outs are used by all the major retailers to sell their products
on the internet. Products presented in this way have a sense of uniformity and clarity, giving the customer
a view of a well organised store that promotes professionalism and good consumer
ethics.
Uploading
This is the term used to describe the
transfer of images from a personal computer file to a server that is connected
to the World Wide Web for display on the internet. For the image shown on
an internet, an original image will be kept in the web site folder. It is
always good practice to retain the original image in a separate folder.
