Bitmap CompuServe GIF, or Graphic Interchange Format, is a file extension for an often animated raster graphics file and is the second most common image format used. What is a GIF file GIF files are image files that can be created by a number of different graphics applications. Files with the. gif file extension can contain up to. A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage. Edit Article wiki How to Edit a Dat File. Five Methods Opening and Editing a DAT File Changing the DAT File Extension in Windows Changing the DAT File Extension in. Details for file extension FRA Fifa World Cup Game Data fe Art Legalscr File FRA Fractal Explorer Animation of Fractal Navigation Project FRA Fractint. The invalid file extension error message can be extremely frustrating when a user wants to upload an image to a social networking site or an online image host. The. File Type Icons is a set of 62 different file extension icons in both AI, ICO and PNG format. BIN file extension. The BIN System file format. BIN Binary files is a non text computer file. Data is encoded with binary code instead of text for storage and processing. Some of the coding can be translated or interpreted into text while the rest is for formatting and other useful functional features. Older Microsoft Word documents work in binary. The BIN file extension often refers to CD disk images. Binary data can be translated into plain text to prevent the code from trying to execute functions. This allows the sending, receiving, and downloading of BIN files. Hex editors are very useful for viewing of binary sequences but text editors can be used as well. Technical details of BIN files. Wario Ware Smooth Moves Ntsc on this page. Gif File Extension Meaning' title='Gif File Extension Meaning' />Files with the BIN extension usually look like junk when viewed directly with a text editor. Without knowledge of which portion of ASCII code is crucial for the file or which program to open the file in, the files are not very useful. These files often contain executable code and data programs that are required by various OSs for the starting of a program. Binary digits bits are grouped in 8 character groups and used to interpret something other than numbers and letters by different programs. This allows images, text, sound, and other files compressed to be found in a BIN file. Headers can contain metadata used by the program to interpret data and identify format. More information about the BIN file format. MF Project Whats In A GIF. We sill start off by walking though the different parts of a GIF file. The information on this page is primarily drawn from the. W3. C GIF8. 9a specification. A GIF file is made up of a bunch of different blocks of data. The following diagram. The file starts. at the left and works its way right. What Does Gif File Extension Stand For' title='What Does Gif File Extension Stand For' />At each branch you may go one way or the other. The. large middle section can be repeated as many times as needed. Technically, it may. GIF file with no image data. Ill show you what these blocks looks like by walking through a sample. GIF file. You can see the sample file and its corresponding bytes below. Actual Size1. 0x. Enlarged1. 00x. 10. Gif File Extension' title='Gif File Extension' />Gif File Extension DownloadConceptually, a GIF file describes a fixedsized graphical area the logical screen populated with zero or more images. Many GIF files have a single image that. Bytes 0. A 0. 0 0. A 0. 0 9. 1 0. 0 0. FF FF FF FF 0. 0 0. FF 0. 0 0. 0 0. 0 2. F9 0. 4 0. 0 0. 0 0. C 0. 0 0. 0 0. 0 0. A 0. 0 0. A 0. 0 0. C 2. D 9. 9 8. 7 2. A 1. C DC 3. 3 A0 0. EC 9. 5 FA A8 DE 6. C 0. 4 9. 1 4. C 0. B. Note that not all blocks are represented in this sample file. I will provide samples of missing. The different types of blocks include. Lets get started with the first blockFrom Sample File. All GIF files must start with a header block. The header takes up the first. These bytes should all correspond to. ASCII character codes. In this article I am explaining how to create a File Extension Filter for the ASP. Net FileUpload Control. On many occasions theres a requirement to upload only. Gif File Extension Definition' title='Gif File Extension Definition' />We actually have two pieces. The first three bytes are called the signature. These should always be GIF ie 4. G, 4. 9I, 4. 6F. The next three specify the. Well only be working. The only other recognized version string. From Sample File 0. A 0. 0 0. A 0. 0 9. The logical screen descriptor always immediately follows the header. This block. tells the decoder how much room this image will take up. It is exactly. seven bytes long. It starts with the canvas width. This value. can be found in the first two bytes. Its saved in a format called the spec. Basically were looking at a 1. As with all the other multi byte values in the GIF format, the least. This means where we would read. A which is. the same as 1. Thus the width of our sample image is 1. As a further example. FF 0. 0 but 2. 56 would be 0. As you might expect, the canvas height follows. Again, in this sample we. A 0. 0 which is 1. Next we have a packed byte. That means that this byte actually has multiple values. In this case, the byte 9. The built in Windows calculator. Palm Vx Software. Be sure. its in scientific or programmer mode, depending on the version of. The first most significant bit is the global color. If its 0, then there is none. If its 1, then a global color table will. In our sample image, we can see that we will have a global color table as will usually. The next three bits represent the color resolution. The spec. says this value is the number of bits per primary color available to the original image. Because i dont much about what this one does, Ill point you to. For now 1 seems to work. Note that 0. 01 represents 2 bitspixel. The next single bit is the sort flag. If the values is 1, then the. This can help the image decoder but. Our value has been left at 0. The last three bits are the. Well, thats a lie its not the actual size of the. If this value is N, then the actual table size is 2N1. From our sample. file, we get the three bits 0. Our actual table size would be 211 22 4. Weve mentioned the global color table. The next byte gives us the background color index. This byte is only meaningful. It represents which color in the global color table. If, by some chance, there is no global color table, this byte should be 0. The last byte of the logical screen descriptor is the pixel aspect ratio. Im not exactly sure what this value does. Most of the images Ive seen have this value. The spec says that if there was a value specified in this byte, N, the actual. N 1. 5 6. 4 for all Nlt 0. From Sample File FF FF FF FF 0. FF 0. 0 0. 0 0. 0. Weve mentioned the global color table a few times already now lets talk. As you are probably already aware, each GIF has its own color. That is, it has a list of all the colors that can be in the image and cannot. The global color table is where that list. Each color is stored in three bytes. Each of the bytes represents. RGB color value. The first byte is the value for red 0 2. The size of the global color table is determined by the value in the packed byte of the. As we mentioned before, if the value from that byte is N, then. N1. This means that the global color table will. N1 bytes in the stream. Size In Logical. Screen Desc. Number Of. Colors. Byte. Length. 02. Or sample file has a global color table size of 1. This means it holds 211224 colors. We can see that it takes up 1. We read the bytes three at a time to get. My Recycle Bin Is Corrupted Vista on this page. The first color is FFFFFF white. This value is given an index of 0. The second color is FF0. The color with an index value of 2 is 0. FF blue. The last color is 0. The index numbers will be important when we decode. Note that this block is labeled as optional. Not every GIF has to specify a global. However, if the global color table flag is set to 1 in the logical. From Sample File 2. F9 0. 4 0. 0 0. 0 0. Graphic control extension blocks are used frequently to. They are completely optional. Since transparency and animations are bit complicated, I will hold off on many of. Transparency and Animation. In the interest of this page being complete, I will at least tell you what. The first byte is the extension introducer. All extension. blocks begin with 2. Next is the graphic. F9, which is the value that. Third up is the total block. Next is a packed field. Bits 1 3 are reserved for future. Bits 4 6 indicate disposal method. The penult bit is. The delay time value follows in the next two bytes. After that we have the transparent color. Finally we have the block terminator which. From Sample File 2. C 0. 0 0. 0 0. 0 0. A 0. 0 0. A 0. 0 0. A single GIF file may contain multiple images useful when creating animated. Each image begins with an image descriptor block. This block is exactly. The first byte is the image separator. Every image. descriptor begins with the value 2. C. The next 8 bytes. An image in. the stream may not necessarily take up the entire canvas size defined by. Therefore, the image descriptor specifies. Next it specifies the. Each of these. values is in the two byte, unsigned format. Our sample image indicates that. This image. does take up the whole canvas size. The last byte is another packed field. In our sample file this byte is 0 so. The first most significant bit in. Setting this flag. More information on the local. The second bit is the interlace flag. The local color table looks identical to the global color table. The local. color table would always immediately follow an image descriptor but will only. It is effective only for the. If no local color table. The size of the local color table can be calculated by the value given in the. Just like with the global color table, if the image descriptor. N, the color table will contain 2N1 colors and will take. N1 bytes. The colors are specified in RGB value triplets. From Sample File 0. C 2. D 9. 9 8. 7 2. A 1. C DC 3. 3 A0 0. EC 9. 5 FA A8 DE 6. C 0. 4 9. 1 4. C 0. Finally we get to the actual image data. The image data is composed of. These codes are combined into the bytes that make up. Ive set an whole other section on decoding these output. LZW Image Data. On this page im just going to tell you how to determine how long the block will be. The first byte of this block is the LZW minimum code size. This value is used to decode the compressed output codes. Again, see the. section on LZW compression to see how this works.