THIS IS NOT BEEN ASKED BEFORE

• Files which are presented as lines of electronic text. 

• These files are readable to the human eye but contain no formatting information and may often be used to store information which requires further processing by another application. 

• Some operating systems will place an EOF (End of file character) after the last line in the text file to denote the end of the txt file.

CCEA Fact File

THIS IS NOT BEEN ASKED BEFORE

• A file format widely used for professional recording and editing.

•  These files use a process known as sampling to store a digital representation of a recorded analogue sound signal. 

• During the sampling process the amplitude of the waveform being received are analysed very quickly and recorded (see diagram below). 

• It is the angular waveform shown below that is played back to the listener. 

• The quality of the sound is dependent upon the frequency of the sampling (sampling rate) and the number of bits used to store the digital value for each sample (sample resolution).

• Generally a WAV file is uncompressed, although wav files can sometimes also be used to store compressed formats. 

• A header in the file will indicate if the file is in compressed or uncompressed format.

CCEA Fact File 

THIS IS NOT BEEN ASKED BEFORE

• Mpegs use a method called delta compression to record and transmit the data representing audio and video files. 

• It works by only sending what has changed since the last recording /transmission of data. 

• For example in the transmission of TV signals where 25 frames are transmitted per second, a full frame / picture is only sent occasionally and in between those transmissions data is  sent relating only to changes in the full frame / picture.

CCEA Fact File 

Describe the main features of each of the following file formats. JPEG [3]

• Uses lossy compression 

• Identifies patterns/similarities which are repeated in an image

•  ... which are stored only once

• Can reduce the file size 

• ... but may lose some of the original image quality 

• Supports up to 24-bit colour 3 × [1] 

CCEA 2024 Q4 c [3 marks]

BITMAP and JPG are two common file formats for images. Evaluate these two file formats with regards to image quality. [6]

JPG

• Uses compression to reduce file size of an image 

• Identifies pixel arrangements that are repeated in the image and stores these once.

Evaluation for image quality JPG:

• Uses lossy compression which can reduces image quality.

• The amount of compression can be controlled as a percentage 

CCEA 2023 Q4 e [Part of an evaluation question for image quality]

Bitmap and JPEG are two file formats used for images. Evaluate the use of each of these formats for an image in a webpage. [6]

Evaluation for an image used on a webpage:

• Results in smaller files which transfer more quickly but which can lead to reduction in detail 

CCEA 2019 Q4 c [Part of an evaluation question for an image used on a webpage]

Describe the main features of each of the following file formats. GIF [3]

• A standard format for both animated and static images 

• Uses lossless compression 

• ... so no image information is lost 

• Colour palette is limited to 256 colours 

• … not ideal for storing digital photos 

• Sound is not supported in animations 3 × [1] 

CCEA 2024 Q4 c [3 marks]

Evaluate GIF format for a photograph to be placed on a webpage.

• GIF stands for Graphics Interchange Format and is one of the file formats used to display indexed-colour graphics and images in HTML documents on the web. 

• This means that a GIF will only display a maximum of 256 colours; 

• as a result, GIFS are great for images with simple illustrations and blocks of colours, like logosw and icons,

• but probably not the best option for photographs. 

Specimen Q3 c

BITMAP and JPG are two common file formats for images. Evaluate these two file formats with regards to image quality. [6]

BITMAP

• Stores data about individual pixels.

• The number of bits determines the number of colours/colour depth.

• The resolution is number of bits per pixel(dpi). 

• The resolution determines the number of colours. 

Evaluation for image quality Bitmap:

• Higher resolution results in better image quality.

• The more bits per pixel, the greater the number of colours.

CCEA 2023 Q4 e [Part of an evaluation question for image quality]

Bitmap and JPEG are two file formats used for images. Evaluate the use of each of these formats for an image in a webpage. [6]

• Bitmap: Each pixel of an image is stored as a pattern which defines its colour/depth using 8/16/32 bits without compression.

Evaluation for an image on a webpage:

• Bitmap Good for continuous tone images.

• Produces large files which take longer to transfer/result in no loss of detail. 

CCEA 2019 Q4 c [Part of an evaluation question for an image used on a webpage]