Image file Formats and Their applications :JPEG,TIFF,GIF,BMP, AND PNG

Image file formats are standardized means to store Digital image data which can be either in Raster  or Vector format .Once rasterized they become a gid of pixels There are several image file formats that can store images either with lossy or lossless compression methods. Each having their advantages and disadvantages .Though no. of Image storing file formats is not very limited.

Some native applications use their own file formats for storing image data such as photoshop (.psd),corel draw(.CDR) that have been created to provide some additional features over conventional file formats.

Recognizing file format

File formats predicts much about file Data. It helps us in listing/sorting of the files which can be opened with a particular kind of application. File format can be simply found at the last of a file name begins with a (.) dot. While some applications may hide this information from the file name to prevent accidental renaming of the file extension/ format, which might make a file unusable in some cases.

Regular/Native image file formats

These image formats are widely used and can be found in almost any digital camera,smartphones  and on internet. The most prominent image file formats includes JPEG,GIF,TIFF,BMP AND PNG. Several other file formats are also popular for their specific features. In this article we will discuss only widely used and accepted image formats.

Native File Formats.

some image processing applications use their own file formats which might have some additional features compared to usual file formats .
for example , photoshop uses .psd(photoshop Document) to store ongoing process ,layers, mask and other data . This kind of files are useful if you like  post processing of images.

JPEG

JPEG is acronym for Joint photo expert groups developed in 1992 .It gained popularity very soon.
JPEG stores Raster images with lossy compression methods. Compressed data is stored in JFIF(file interchange format) which reduces the file size dramatically while remaining good quality. It can be found  nearly in any digital camera smartphones and in other such devices.

Over the couple of decade this extension has become extremely popular and widely distributed because of its high compression technique. It let us store huge no of files in tiny storage .

• JPEG can store 8-bit grayscale image  and 24bit RGB color image. 8×3 each or different three colors.
• 8 bits for each color means  2^8=256 different shades/tints of each color usually counted 255 . 
• Each color has a value ranging between 0-255 . (0,0,0) gives black and (255,255,255) gives pure white color.
• It can reduce BMP file size to ten times sustaining good quality.

JPEG uses lossy compression methods which reduces file size , suitable for easy sharing.

Disadvantages

JPEG also have many disadvantages which are given below.

• Lossy compression reduces quality of the pixel data in the images.
• These files suffer generation degradation ,each time you edit and save them a little chunk of pixel data is lost . it depends on the application used for post processing. however this can be controlled by means of using advance software for editing.

JPEG-2000

JPEG-2000 is an improvement to jpeg ,first published in 2000 . It uses both lossy and lossless compression  to give more controls on the image quality . This file format uses different technique to store data than JPEG and gives improved quality and compression ratio but it didn't  gained popularity because it requires more computational power to process images . Despite additional features of JPEG 2000, the older JPEG file format remains the popular choice among people . 

JPEG 2000 is currently used in professional movie editing and distributions. Some cinema also use JPEG 2000 for individual movie frames.

Gif

Gif (Graphic Interchange Format ) is a bitmap image format . It was developed in 1987 by CompuServe and came into widespread uses on web due to its support and portability all around  the world. It uses 8 -bit col;or space and lossless compression technique to store image data.

• GIF stores a raster image file that supports  upto 2^8=256 color space per pixel chosen from a 24 bit RGB palette.
• It supports animation.We can use 256 colors for each separate frame, hence suitable for simpler graphic animation.
• GIF uses Lempel-Ziv-Welch (LZW) lossless compression technique that lest us store image data without compromising image clarity.
• The 8 bit color representation allows us simpler image color than JPEG which can represent multi-color gradients.It is better to use GIFs when colors are of less importance.
• GIF  can hold transparency it pixels which allows blending with different backgrounds compared to JPEG Format which uses a rectangular background

TIFF

Tiff or (Tagged Image File Format) is a binary format which supports both lossy and lossless compression.it was initially developed by Aldus Corporation in 1986 and become international in 1993. A year later in 1994 it was merged with Adobe System .

This format proved to be very useful for photography purpose in storing high quality raster images with more details.

Raster Image when zoomed in

• It can represent color depth ranging between 1-24-bit.They also support multi-layer and pages.
• These image formats have capability to remain transparency in pixels that allows blending with different colors background.
• Usually they are large in size which makes them unsuitable for web but are widely used for printing purpose since they contain more clarity in pixels than JPEG or any other lossy compresed file.
• it is a good file format for storing raw image data which can be  post processed and exported in any other easy sharing image formats.its very useful for photography .Some Scanners,Fax and OCR also utilize this file format.

• TIFF or TIF are interchangable file fotmats .There is also a varient GeoTIFF which allows georeferencing information to be embedded within a TIFF file

PNG

PNG(Portable Network Graphics) was developed by PNG Development Group in 1996,now (Donated to W3C) .

The main objective behind its development was to create a more flexible and free alternative to GIF which was patented at the time.

A PNG Logo with transparency on white background

PNG is a link between 8-bit GIF and 24-bit JPEG.

• PNG-8bit is similar to GIF that supports 256 colors and 1 bit transparency, However PNG-24 can represent more than 16 million colors.
• IT uses lossless compression to store pixel data hence file size is greater compared to its primitive counterpart JPEG.
• PNG stores a good pixel clarity with sharp edges and boundaries which makes it a suitable choice for web,Graphic-designing and Drawings.
• The alpha channels allow transparency on a scale from fully opaque to completely  transparent.
• IT is possible to work with layers also images can be stored without adding a background unlike JPEG which stores image in a rectangular base.

Except these,PNG has the ability to store image meta data such as Time,Date,ISO,Aperture,Shutter Speed and much more which is useful for some purpose.Unlike JPEG These files do not suffer generation degradation to much extent  and are good for post processing.

BMP

BMP is a bitmap image file developed by Microsoft in 1986 for storing bitmap files in device independent bitmap(DIB) format .It allows windows to display bitmaps on any type of device . Almost every device can display bitmap files due to its simple structure and color rendering methods.

• A bitmap file header contains information about the type,size and layout of the layout independent bitmap file.
• A bitmap information header that specifiesthe compression type, dimension, and color formats .
• A color table defined as an array however it is not present in 24 bit bitmap file.

BMP files contain RGB data that can be either1,4,8 or 24-bit . 

Pros and Cons 

• Bitmap files are easy to create and display on any device due to its simple structure.
• These files give better result in dot-format output devices such as CRT monitors and some printers.
• PIxel values may be modified by altering a palette either individually or in a large group.

• Bitmap files are larger compared to counterparts especially if the image contains large number of colors.
• Shrinking image to reduce file size by throwing away pixels might result in a poor quality picture. To avoid losses they should be printed in their original size they were created.

There are several other Image formats currently in use.We have discussed here the most popular image file formats in use and hope this article was helpful to you.If you have a suggestion or query ,Let us know. We take your opinion potentially.

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