FlashPix
Encyclopedia
FlashPix is a bitmap
ped computer graphics
file format where the image is saved in more than one resolution
. Though this makes it larger even than a TIFF file, when a request is sent for the file by a Web browser
only the resolution required for the current screen resolution is sent to the browser; this therefore saves on bandwidth
and download time.
In 1995, a consortium
of Eastman Kodak
(PhotoCD), Microsoft
, Hewlett-Packard
, and Live Picture Inc were looking for a powerful image file solution, and Live Picture's solution was the best approach for handling large image files.
Each image is stored with its sub-resolutions.
Each resolution is divided by 2, until the entire image can fit in a single tile.
Tile size is variable, but the default usage is to have 64x64 pixels tiles (IVUE was using 256x256 pixels). Each tile can be compressed independently of other tiles using various algorithms (LZH, JPEG, RLE).
Each pixel can have any number of channel of any size (for instance a 16bits CMYK image), interleaved or not. Including Alpha channel.
The result is a file bigger than the original file (at same compression), but never more than 33%. It allows efficient access to only the needed parts of the image without having to read the entire file.
Let's take a 10200x7650 16bits CMYK image using 64x64 tiles. As a normal uncompressed image it would occupy 595MB of disk space.
FlashPix, however, will store:
Total size: ~ 793MB
A viewer (like photo editing software) will access only the needed part... In the worst case, for a 1680x1050 display, 53x33 tiles (56MB) are needed in memory, whatever portion of the image is being used. Meaning that on a 2GB computer, 36 such images (595MB) can be used simultaneously in the same project.
Bitmap
In computer graphics, a bitmap or pixmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to...
ped computer graphics
Computer graphics
Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....
file format where the image is saved in more than one resolution
Display resolution
The display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...
. Though this makes it larger even than a TIFF file, when a request is sent for the file by a Web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
only the resolution required for the current screen resolution is sent to the browser; this therefore saves on bandwidth
Bandwidth (computing)
In computer networking and computer science, bandwidth, network bandwidth, data bandwidth, or digital bandwidth is a measure of available or consumed data communication resources expressed in bits/second or multiples of it .Note that in textbooks on wireless communications, modem data transmission,...
and download time.
History
FlashPix is based on the IVUE file format, the tiled/multi-resolution image file format that was used by the Live Picture software (Live Picture Inc).In 1995, a consortium
Consortium
A consortium is an association of two or more individuals, companies, organizations or governments with the objective of participating in a common activity or pooling their resources for achieving a common goal....
of Eastman Kodak
Eastman Kodak
Eastman Kodak Company is a multinational imaging and photographic equipment, materials and services company headquarted in Rochester, New York, United States. It was founded by George Eastman in 1892....
(PhotoCD), Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
, Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
, and Live Picture Inc were looking for a powerful image file solution, and Live Picture's solution was the best approach for handling large image files.
Technical Overview
FlashPix files have the .fpx file extension. FlashPix uses Microsoft's structured storage format which stores hierarchical data in a single file.Each image is stored with its sub-resolutions.
Each resolution is divided by 2, until the entire image can fit in a single tile.
Tile size is variable, but the default usage is to have 64x64 pixels tiles (IVUE was using 256x256 pixels). Each tile can be compressed independently of other tiles using various algorithms (LZH, JPEG, RLE).
Each pixel can have any number of channel of any size (for instance a 16bits CMYK image), interleaved or not. Including Alpha channel.
The result is a file bigger than the original file (at same compression), but never more than 33%. It allows efficient access to only the needed parts of the image without having to read the entire file.
Let's take a 10200x7650 16bits CMYK image using 64x64 tiles. As a normal uncompressed image it would occupy 595MB of disk space.
FlashPix, however, will store:
- The original image: 10200x7650 pixels in 160x120 tiles (~ 595MB, but usually less using RLE or LZH per-tile).
- Sub-resolution 1: 5100x3825 pixels in 80x60 tiles (~ 149MB)
- Sub-resolution 2: 2550x1913 pixels in 40x30 tiles (~ 37MB)
- Sub-resolution 3: 1275x957 pixels in 20x15 tiles (~ 9MB)
- Sub-resolution 4: 638x479 pixels in 10x8 tiles (~ 2.3MB)
- Sub-resolution 5: 319x240 pixels in 5x4 tiles (~ 598KB)
- Sub-resolution 6: 160x120 pixels in 3x2 tiles (~ 150KB)
- Sub-resolution 7: 80x60 pixels in 2x1 tiles (~ 37.5KB)
- Sub-resolution 8: 40x30 pixels in a single tile (~ 9KB)
Total size: ~ 793MB
A viewer (like photo editing software) will access only the needed part... In the worst case, for a 1680x1050 display, 53x33 tiles (56MB) are needed in memory, whatever portion of the image is being used. Meaning that on a 2GB computer, 36 such images (595MB) can be used simultaneously in the same project.