Monday, February 21, 2011

colour depth;

Colour depth describes the number of bits per pixel (bpp) that can be displayed on a computer. Each bit represents two colours, because it has a value of 0 or 1. The higher the colour depth, the more wider the range of distinct colours (more bpp = more colours displayed).

Since the colour depth describes the range of colours in an image, it would affect how the image would appear. An image with a high colour depth would, obvious, have a wider variety of colours and shades, which could give the image more depth. As opposed to an image with a low colour depth, with less colours and shades, which would make the image appear blunt and dull.

The following is a range of colour depth of the same image:

1 bit

2 bits

4 bits

8 bits

24 bits

colour depth vs sampling rate;

The colour depth affects the quality of a still media - whether they are images or video frames and the sampling rate affects sound. Videos have both have visuals and audio, which means that it can be affected according to both colour depth and sampling rate.Still media, on the other hand, are purely visual (with no audio) so it won't be affected by the sampling rate.

sampling rate;

Sampling is the reduction from continuous signals to discrete signals. In digital audio (videos), the sampling rate is the number of times per second that a sound wave is measured. It affects the quality and reproduction of the sound so the higher the sampling rate, the more accurate the sound is.
The following is a comparison between a lower sampling rate (8 samples) and a higher sampling rate (16 samples):

bit & byte;

bit;
A bit is also known as a binary digit. A bit is the unit of measurement used for information storage in computers. It only has one single binary value, which can be either 0 or 1 ('true' or 'false'). The computer converts all data into bits and bytes through alphanumeric and decimal to binary conversion. This means that alphabets and letters are all represented into bits.
There are 8 bits in a byte.

byte;
It is also a unit of measurement used to describe the storage capacity (size of file) and transfer rate of digital media.
The following are size conversions from bytes:
1 kb - 1 024 bytes
1 mb - 1 048 576 bytes
1 gb - 1 073 741 824 bytes

number system;

Digital data is based on the binary numeral system, or base-2 number system. This system represents numeric values using two symbols (numbers): 0 and 1. (see bit & byte)

forms of digital media;

The following are examples of digital media:
• mobile phones (cellular phones)
• compact discs
• digital video
• televisions
• e-books
• internet
• video games
• game consoles
• computers
• interactive media

inkscape drawing;

drawing

ms word drawing;

Tuesday, February 15, 2011

brush tools;

bucket fill;

The bucket fill tool fills an area (either of selection or similar colours) with a colour or pattern.

blend/gradient;

The blend/gradient tool fills an area with a gradient (of both the foreground and background colour or an existing gradient).

pencil;

The pencil tool paints hard-edged lines - not anti-aliased.

paintbrush;

The brush tool paints smooth or fuzzy-edged lines - anti-aliased or feathered.

eraser;

The eraser tool erases pixels from a layer

airbrush;

The airbrush tool is a paint tool with variable pressure (pressure can vary).

ink;

The ink tool paints anti-aliased lines (with a simulation of a nib).

clone;

The clone tool copies pixel from one part of an image to another.

heal;
The heal tool heals irregularities in an image.

perspective clone;
The perspective clone tool allows you to clone a part of an image according to the perspective you want.

blur/sharpen;
The blur or sharpen tool can blur or sharpen an image, alternatively.

smudge;
The smudge tool spreads pixels in a specific direction.

dodge/burn;
The dodge or burn tool lightens or darkens an image's shadows, mid tones or highlights.

selection tools;

rectangle selection;

The rectangle selection selects a rectangular or square area/region of an image.

ellipse selection;

The ellipse selection selects a circular or elliptical area/region of an image.

free selection/lasso;

The free selection or lasso tool draws free-form selections.

fuzzy selection/magic wand;

The fuzzy selection or magic wand selects regions with the same/similar colours, that are next to each other.

by colour;

Just like the magic wand, the by colour tool selects the same/similar colours, all over the image, regardless of whether they are next to each other or not.

scissors;

The scissors tool is used to select shapes, by means of path. (similar to the path tool and lasso)

foreground select;

The foreground select tool allows you to extract foreground (or portion of image) from an active layer.

other tools;

path;
The path tool allows selecting and modifying paths.

colour picker;
The colour picker selects the colour of a pixel and sets it as either foreground/background colour.

magnify;
The magnify tool alters the zoom level of an image.

measure;
The measure tool shows distances and angles.

text;
The text tool inserts text into your image.

transform tools;

move;
The move tool moves layers and selections.

align;
The align tool aligns or arranges layers and/or other objects.

crop;
The crop tool crops or clips the image/canvas.

rotate;
The rotate tool rotates the active layer, selection or path.

scale;
The scale tool scales (changes the size of) the active layer, selection or path.

shear;
The shear tool shifts part of the image to another direction.

perspective;
The perspective tool changes the perspective of the active layer, selection or path.

flip;
The flip tool flips layers and selections.

Friday, February 11, 2011

colour depth;

Colour depth is describes the number of bits per pixel (bpp) that can be displayed on a computer. Each bit represents two colours, because it has a value of 0 or 1. The higher the colour depth, the more wider the range of distinct colours (more bpp = more colours displayed).
The following are examples of colour depth:
• 1-bit allows 2 colours
• 4-bit allows 4 colours
• 8-bit allows 256 colours
• 16-bit allows 65 536 colours
• 24-bit allows 16 777 216 colours

animated gif;

An animated GIF is one of many graphic file types. It is composed of several frames/layers of different images stacked on top of each other. These images, when compressed, can create a series of movement (animation). This file type is saved under the filename extension .gif.
The following are examples of animated GIFs:

framebuffer;

A framebuffer is an area of memory used to hold data/information for one frame or picture. This information consists of colour values fo every pixel on the screen. The framebuffer holds a bitmapped image as it is being displayed on the screen. It is the size of the maximum image that can be displayed on the screen.

compression;

Image compression is done by reducing the size of the original image/graphic file without degrading the quality to the point where the image is unrecognisable. This is done to save memory space and to lesson the time in which the file is sent/uploaded to the Internet. The most common method of image compression is by the saving the image in file formats such as JPEG and GIF.

filename extension;

A filename extension is a suffix added at the end of the name of a computer file. This is used to indicate the type of file and the file format (encoding convention). Some common filename extensions include: .jpg, .png, .gif, .psd, etc.
The following is a screenshot of a variety of different filename extensions:

resolution;

The resolution of an image is the number of pixels per square inch/dots per inch (dpi) in a computer-generated image. It describes the details an image holds so the greater the resolution of an image, the better quality there is.
The following is a comparison between the same image, each with different resolutions:

dpi;

Dots per inch;
DPI, very similar to PPI (pixels per inch), is the measure of the number of pixels per inch in an image/graphic. It is used to specify the image resolution and is a term to describe the measure of sharpness of an image.

cpu;

Central Processing Unit;
The CPU is a microchip that serves as the computer's 'brain' and 'heart'. It is this chip that receives data input, processes information and executes instructions.
The following is an image of the CPU (stored in -):
add image

morph;

Morphing is a special effect to transform one image to another (or perhaps more). This transition from one image to the next is seamless, which means that the first image gradually changes features and characteristics until it completely matches the next.
The following is an example of morphing:

frame;

A frame, in animation, is one layer of a still image. A compilation of frames together can form a series of movement (animation).

fps;

Frames per second;
It indicates the speed and/or time in which a frame (or layer) remains still. It changes the total speed of the entire animation, according to the speed of each frame.
The following are a variety of animated avatars I have made with GIMP:

mirror;

A method to adjust/alter an image is to mirror it. To mirror an image is the same as flipping - it is when an image is a reflected duplicate of the original image, only in reverse.
The following is an example of an image that is mirrored (horizontally):

video card;

A video card is an expansion card that translates data from the CPU and display it on the monitor/screen. Also called graphics accelerators, video cards accelerates both 2D and 3D graphics rendering. Since almost all of the programs nowadays are graphics-oriented, the video card can make just about all programs run more efficiently.

flip;

Flipping is a method that can alter/adjust an image. By flipping, you create a reflection of the original image, somewhat like a mirror. An image can be flipped either horizontally or vertically. This is done by rotating the image 180 degrees.
The following is an image flipped vertically:

bmp

BMP is short for bitmap. The BMP format stores colour data for each pixel in the image without the use of compression. This makes the image appear sharper/crisper than other file formats that use compression and higher in quality. However, bitmap files are much larger in size, as opposed to other formats that compresses the image.

pixel;

A pixel is the smallest unit/element of an image that can be controlled. They are commonly depicted as dots or squares and each pixel can only be one colour. So an image is basically a compilation of individual dots (of different colours) on the screen. With art programs, we can specify the size of the canvas by using pixels.
The following is an example of an image magnified 2000%: (the pixels are more distinct)