File:Quilt design as 46x46 uncompressed GIF.gif

Quilt_design_as_46x46_uncompressed_GIF.gif(46 × 46 pixels, file size: 3 KB, MIME type: image/gif)

Commons-logo.svg This is a file from the Wikimedia Commons. The description on its description page there is shown below.
Commons is a freely licensed media file repository. You can help.

Summary

Description
English: An example of an uncompressed GIF image. See encoding details below.

Licensing

Encoding details

Size: 46 × 46 pixels, 128 colors. Format: Uncompressed GIF with 7-bit symbols (8-bit codes), packed 1 raster line per sub-block, with an initial CLEAR code at the beginning of each raster line. The image data begins with the "LZW minimum code size" of 7, indicating that the symbols (color table indices) are seven-bit values coded as 8-bit codes. (7-bit color indices are used as the color table has only 128 entries.) This is followed by 46 sub-blocks of image data, one sub-block per raster line, each 48 bytes long. Each sub-block begins with a byte giving the number of data bytes (47 = 2FH), followed by the CLEAR code (80H), followed by the color indices for the 46 pixels in the given raster line, one pixel per byte. The 46 raster sub-blocks are followed by a two-byte sub-block with the STOP code (length byte 01 plus STOP code 81H), followed by the terminating null sub-block (00). -- Elphion (talk) 01:28, 24 May 2011 (UTC)

Each byte of the file is shown below by its hexadecimal value. The first 9 lines as for a normal gif are: the header, Logical Screen Descriptor and a 128-color table . The rest is image data with one byte (never exceeding 7FH) for each pixel.
The image data is arranged in blocks each consisting of:
  • 2FH means there are 47 bytes to follow (Visible at center column of the listing below)
  • 80H is a CLEAR code These periodic CLEAR codes prevent the unintended decoding progressing from 8-bit to 9-bit codes.
  • An image line of 46 pixels.
As a result of the listing width equalling one image line, the image outline can be seen in the data. Cuddlyable3 (talk) 08:43, 24 May 2011 (UTC)
Image:Uncompressed gif file.PNG
Date (UTC)
Source I created this image from scratch. I release it to the Public Domain.
Author Elphion (talk) 16:43, 31 May 2011 (UTC)

Licensing

Public domain This work has been released into the public domain by its author, Elphion at English Wikipedia. This applies worldwide.
In some countries this may not be legally possible; if so:
Elphion grants anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

Original upload log

The original description page was here. All following user names refer to en.wikipedia.
  • 2011-05-24 01:28 Elphion 46×46× (2620 bytes) I created this image from scratch as an example of an uncompressed GIF image. I release it to Public Domain. Size: 46 x 46 pixels, 128 colors. Format: Uncompressed GIF with 7-bit symbols (8-bit codes), packed 1 raster per sub-block, with an initial CL


Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

image/gif

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeDimensionsUserComment
current09:05, 18 January 202446 × 46 (3 KB)ElphionReverted to version as of 08:20, 23 May 2014 (UTC): The version of 14 May 2023 is compressed, which destroys the whole point of the image.

The following page uses this file: