What is a bitmap file?

Question 1: What is a bitmap file and what files does it contain? Bitmap file is an image file format based on pixel storage, corresponding to vector file, which is an image file format based on contour storage.

Bitmap file format, such as: JPG, GIF. TIF。 BMP, PDF, etc.

Question 2: What is a BMP bitmap file? How to create a new BMP bitmap file in a folder? BMP is a picture file format. Open the folder directly, right-click and select New, and then select BMP bitmap file.

Question 3: What is a picture file? As the name implies, picture files.

Image format is a format for storing image files, usually JPEG, TIFF, RAW, BMP, GIF, PNG, etc. Because the image file shot by digital camera is very large, but the storage capacity is limited, the image is usually compressed and then stored.

JPEG2000 format

JPEG 2000 is also formulated by JPEG organization, and its official name is ISO 15444. Compared with JPEG, JPEG 2000 has higher compression rate and is a new generation of still image compression technology with more new functions.

As an upgraded version of JPEG, JPEG2000 has a compression ratio about 30% higher than JPEG. Unlike JPEG, JPEG2000 supports both lossy and lossless compression, while JPEG can only support lossy compression. Lossless compression is very useful for saving some important pictures. An extremely important feature of JPEG2000 is that it can realize progressive transmission, which is similar to the progressive display of GIF, that is, the outline of the image is transmitted first, and then the data is transmitted step by step, so as to continuously improve the image quality and make the image display from hazy to clear, instead of slowly displaying from top to bottom as JPEG does now.

In addition, JPEG2000 also supports the so-called region of interest function. You can arbitrarily specify the compression quality of your region of interest on the image, or you can choose the specified part to decompress first. Compared with JPEG, JPEG 2000 has obvious advantages and backward compatibility, and it is just around the corner to replace the traditional JPEG format.

JPEG2000 can be applied to the traditional JPEG market, such as scanners, digital cameras, and other emerging fields, such as network transmission and wireless communication.

TIFF format

TIFF (Tag Image File Format) is a widely used image format in Mac. Developed jointly by Aldus and Microsoft, it was originally designed for cross-platform storage of scanned images. It is characterized by complex image format and much information stored. It is precisely because it stores a lot of subtle information of the image and the quality of the image is also improved, so it is very conducive to the reproduction of the original.

There are two forms of this format: compressed and uncompressed, in which compressed can be stored as LZW lossless compression scheme. However, due to the complex structure and poor compatibility of TIFF format, sometimes your software may not correctly identify TIFF files (most software has solved this problem now). At present, it is also very convenient to transplant TIFF files on Mac and PC, so TIFF is now one of the most widely used image file formats on microcomputers.

Photoshop document

This is a Photoshop document (PSD), which is a special format of Photoshop, the image processing software of the famous Adobe company. PSD is actually a draft of Photoshop graphic design, which contains various design samples such as layers, channels and masks, so that the last design can be modified when the file is opened next time. Among the various image formats supported by Photoshop, PSD has much faster access speed and more powerful functions than other formats. With the wider application of Photoshop, we have reason to believe that this format will gradually become popular.

PNG format

PNG (Portable Network Graphics) is a new network image format. At the end of 1994, because Unysis announced that GIF had a patented compression method, the author of GIF software was required to pay a certain fee, which promoted the birth of free png image format. PNG combines the advantages of GIF and JPG from the beginning, and intends to replace these two formats in one fell swoop. 1 996 65438+1October1was proposed by PNG to the international network alliance and was recommended and recognized. Most drawing software and browsers began to support PNG image browsing. Since then, the PNG image format has been full of vitality.

PNG is the most undistorted format at present, which absorbs the advantages of GIF and JPG, has rich storage forms and has two color modes of GIF and JPG. Another feature of it is that it can compress image files to the maximum extent to facilitate network transmission, but it can keep all images.

Question 4: What is a bitmap file with the extension BMP? How to create in a folder? BMP is an image.

You can make a picture with ps and save it as a bmp picture.

This format is Microsoft's default picture format.

After downloading the picture, open it in the drawing and save it as.

There are several kinds of bmp color quality.

Take a look for yourself, and you will be prompted before saving.

Question 5:. Bmp is a bitmap. What does bitmap mean? What's the difference between it and JPEG? Bitmap format (BMP) is an image file format that has nothing to do with hardware devices and is widely used. It uses bitmap storage format and does not use any other compression except image depth, so the BblP file takes up a lot of space. The image depth of BMP file can be selected as lbit, 4bit, 8bit and 24bit. When data is stored in a BMP file, images are scanned from left to right and from bottom to top. Because BMP file format is the standard for exchanging data related to drawings in Windows environment, all graphics and image software running in Windows environment supports BMP image format. A typical BMP image file consists of three parts: a bitmap file header data structure, which contains information such as the type and display content of the BMP image file; Bitmap information data structure, including BMP image width, height, compression mode, defined color and other information. JPEG is the abbreviation of Joint Photographic Experts Group. The file name is. . Jpg or. Jpeg, which is the most commonly used image file format. It is a lossy compression format organized by the Software Development Association. It can compress the image in a small storage space, and the repeated or unimportant data in the image will be lost, so it is easy to damage the image data. Especially, if the compression ratio is too high, the quality of the restored image after final decompression will obviously decrease. If you pursue high-quality images, you should not use too high compression ratio. But JPEG compression technology is very advanced. It uses lossy compression to remove redundant image data, and can display very rich and vivid images at the same time, in other words, it can obtain better image quality with the least disk space. Moreover, JPEG is a very flexible format, which has the function of adjusting image quality, allowing files to be compressed at different compression ratios and supporting multiple compression levels. The compression ratio is usually between 10: 1 and 40: 1. The higher the compression ratio, the lower the quality. On the contrary, the smaller the compression ratio, the better the quality. For example, a BMP bitmap file of 1.37Mb can be compressed to 20.3KB Of course, you can also find a balance between image quality and file size. JPEG format mainly compresses high-frequency information and preserves color information well. It is suitable for the Internet, can reduce the image transmission time, can support 24-bit true color, and is also widely used in images that need continuous tone. JPEG format is the most popular image format on the network at present, which can compress files to a minimum. When stored in JPEG format in Photoshop software, the compression level of 1 1 is provided, which is represented by 0- 10. Level 0 has the highest compression ratio and the worst image quality. The compression ratio can reach 5: 1 even if the quality maintenance with almost no loss of details is adopted. When saving in BMP format, you will get a 4.28MB image file. When saved in JPG format, the file size is only 178KB, and the compression ratio reaches 24: 1. After many comparisons, eight-level compression is the best ratio of storage space and image quality. JPEG format is widely used, especially on the Internet and CD-ROM. At present, all kinds of browsers support JPEG as the image format, because the file size of JPEG format is small and the download speed is fast. As an upgraded version of JPEG, JPEG2000 has a compression ratio about 30% higher than that of JPEG, and supports both lossy and lossless compression. An extremely important feature of JPEG2000 format is that it can realize progressive transmission, that is, the outline of the image is transmitted first, and then the data is transmitted step by step, so as to continuously improve the image quality and make the image display from hazy to clear. In addition, JPEG2000 also supports the so-called region of interest function, which can arbitrarily specify the compression quality of the region of interest on the image, or select the specified part to decompress first. Compared with JPEG, JPEG2000 has obvious advantages and backward compatibility, so it can replace the traditional JPEG format. JPEG2000 can be applied to both traditional JPEG market, such as scanners and digital cameras, and emerging fields, such as network transmission and wireless communication.

Question 6: How to create a bitmap file? Urgent ~ you can use any drawing software, and then you can choose bmp bitmap as the file type when saving.

Question 7: The size of bitmap file and the size of bitmap bfSize specify the file size, including this 14 byte bizizeimage = biWidth' * biheight. It should be noted that the biWidth' in the above formula must be an integer multiple of 4 (so it is not biWidth, but biWidth', which means that it is greater than or equal to the integer multiple of biwidth and the nearest 4. For example, if biWidth=240, biwidth' = 240 If biWidth=24 1, biWidth'=244) If bipression is BI_RGB, this item may be zero.

Question 8: What is the format of bitmap suffix att: at Question 9: Picture file BMP: What is the Windows bitmap?

Windows bitmaps can store a single raster image of any color depth (from black and white to 24-bit color). Windows bitmap file format is compatible with other Microsoft Windows programs. It does not support file compression, nor does it apply to web pages.

Generally speaking, the disadvantages of Windows bitmap file format outweigh the advantages. To ensure the quality of photo images, please use PNG files, JPEG files or TIFF files. BMP file is suitable for wallpaper in Windows.

Advantages:? BMP supports 1 bit to 24-bit color depth.

? BMP format is widely compatible with existing Windows programs (especially older programs).

Disadvantages:? BMP does not support compression, which will make the file very large.

? The Web browser does not support BMP files.

Pcx: computer brush

PC brush pictures (also known as Z-Soft bitmaps) store a single raster image at any color depth. Brush drawing is more widely used in early Windows programs and programs based on MS-DOS. Brush drawing is compatible with many newer programs. PCX pictures support RLE internal compression.

Advantages:? PCX is a standard format between many Windows-based programs and MS-DOS-based programs.

? PCX supports internal compression.

Disadvantages:? Web browser does not support PCX.

PNG: portable network graphics

PNG pictures store a single raster image at any color depth. PNG is a platform-independent format.

Advantages:? PNG supports advanced lossless compression.

? PNG supports alpha channel transparency.

? PNG supports gamma correction.

? PNG supports interleaving.

? The latest web browsers support PNG.

Disadvantages:? Older browsers and programs may not support PNG files.

? As an Internet file format, PNG provides less compression than JPEG lossy compression.

? As an Internet file format, PNG does not support multi-image files or animation files. GIF format supports multi-image files and animation files.

JPEG: Joint Photographic Experts Group

JPEG pictures store a single raster image in 24-bit color. JPEG is a platform-independent format that supports the highest level of compression. However, this compression is lossy. Progressive JPEG files support interleaving.

You can increase or decrease the compression level of JPEG files. However, the file size is at the expense of image quality. The compression ratio can be as high as 100: 1. (JPEG format can easily compress files at the ratio of 10: 1 to 20: 1, and the image quality will not decrease. ) JPEG compression can handle realistic photographic works well. However, JPEG compression can not provide ideal results for simple works with few colors, strong contrast, solid borders or pure * * * fields. Sometimes the compression ratio is as low as 5: 1, which seriously loses the integrity of the picture. The reason for this loss is that JPEG compression scheme can compress similar tones well, but JPEG compression scheme can't handle the strong difference of brightness or pure * * * domain well.

Advantages:? Photographic works or realistic works support advanced compression.

? The file size can be controlled by variable compression ratio.

? Support interleaving (for progressive JPEG files).

? JPEG widely supports Internet standards.

Disadvantages:? Lossy compression will reduce the quality of the original image data.

? When you edit and resave a JPEG file, JPEG will mix the quality of the original picture data. This decline is cumulative.

? JPEG is not suitable for simple pictures with few colors, similar colors in a large area or obvious brightness difference.

GIF: graphic interchange format

GIF pictures store single raster image data or multiple raster image data in 8-bit colors or 256 colors. GIF pictures support transparency ... >>

Question 10: What is a vector diagram? What is a bitmap? To put it simply, the vector diagram can be infinitely enlarged without distortion or small squares; The valve bitmap will be blurred when enlarged, and finally it can be seen that it is composed of small squares;

For example, when printing a large-size advertisement, you need to use a vector diagram or a bitmap, which will become a grid when enlarged.