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What are Bitmap files?

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  #1  
Old 18-01-2011
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What are Bitmap files?
  

I have scanned my desktop machine which runs Windows XP operating system and my antivirus software has detected some malicious BMP files which I have removed. So my computer system is secured now but I was just willing to know about Bitmap files so I ask about the same to my big brother. He explained me about the same which I didn't got at all because of which I am asking you guys that what are the bitmap files and what do they do?

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  #2  
Old 18-01-2011
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Re: What are Bitmap files?

As its name implies almost the bitmap (literally "bit map") can store an image in the color of each pixel. "Pixel" is short for "picture element": a bitmap image is composed of a number of pixels, each pixel representing a point of the image, a pixel can be only one color at a time and c is well happen on an image to represent a set of colors. An image is always rectangular. Known size of an image the number of pixels that compose the length and height, plus the image size, the greater the image quality is good.
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  #3  
Old 18-01-2011
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Re: What are Bitmap files?

For example, an image of dimension 640 ? 480 is composed of 640 pixels in length and 480 pixels wide for a total of 640 ? 480 = 307,200 pixels. There are many types of bitmaps.
  • the monochrome, where each pixel can only have two aspects, black or white
  • 16 color bitmaps, where each pixel can have 16 different aspects,
  • 256 color bitmaps in which each pixel can have 256 different aspects,
  • 24 bit bitmaps, where each pixel can have 16,777,216 different aspects.

To understand how an image will remember these aspects, and why there are more colors in an image, the image occupies space on the disk, you need to know what a byte. Reminder: the byte is the smallest unit of measure for a file one byte can represent a character, in fact, a byte comprises 8 bits which can each take two values: 0 or 1; gold 2 to the 8th power , it is 256. A byte can have a value of 256, which can count from 0 to 255.
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  #4  
Old 18-01-2011
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Re: What are Bitmap files?

The number represented by the byte or a color that matches the computer recognizes. A monochrome bitmap occupies little space because each pixel has only two possible aspects, a pixel can be represented by a bit, but as there is no bit lonely, a byte is a series of 8 pixels. Similarly in a 16-color bitmap a byte represents only 2 pixels: if two consecutive pixels could be 16 different aspects each, then there is 16x16, ie 256 possible combinations, and found the byte . Things are simplified in a 256-color bitmap for each byte represents a pixel. 256-color bitmaps are often redefined color palette, allowing them to display a wide variety of colors, but still limited to 256 colors per image.

It remains the most common case: the 24-bit bitmap, where it takes 3 bytes to represent a pixel for each color can be defined by 3 characteristics (Chrome-saturation-brightness or red-green-blue), each of these characters can be expressed on a scale from 0 to 255, hence the usefulness of 3 bytes (or 24 bits) to represent a pixel. So there can be 256 ? 256 ? 256 or 16,777,216 possible colors. Note that a double-byte encoding allows the production of 256 ? 256 = 65,536 colors.

Little exercise: Can you predict the size of a 24-bit bitmap with dimensions 432 ? 512?
Solution: This image is composed of 432 ? 512 = 221,184 pixels, each pixel is coded on 3 bytes, which is a size of 221 184 x 3 = 663,552 bytes = 648 KB; to note that the file size will be bigger a few bytes in reality because there are other minor details to be stored (eg dimensions themselves).
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  #5  
Old 18-01-2011
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Re: What are Bitmap files?

The RGB system (Red-Green-Blue) is the system used to encode the 24-bit color. English, it says RGB (Red-Green-Blue). Its principle is relatively simple: we express the quantities of red, green and blue needed to recreate the color (imagine that you mix paints) of 3 bytes and are expressed on a scale from 0 to 255, that is (coincidentally), that can express a byte.

For example, white corresponds to 255 - 255 - 255, the dark at 00 - 00 - 00, red at 255 - 00 - 00, green at 00 - 255 - 00, Blue 00 - 00 - 255. Three identical values lead to a shade of gray. We can call jusq'? 16,777,216 different colors, although the human eye distinguishes Moye does that 700 ... You can test this using any drawing software (Paint style) that allows you to create your own colors ... In HTML, colors are expressed with a code of the form # RRGGBB where RR is the red value, GG the green value, blue BB value, all in hexadecimal, that is to say base 16
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  #6  
Old 18-01-2011
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Re: What are Bitmap files?

You may want to completely remove Adobe for the reason that it seems to be corrupted or outdated, which leads to frequent error messages, etc. But sometimes fully uninstalling and removing Adobe can be pretty tough.

Generally speaking, users can uninstall Adobe by going to Control Panel - Add/ Remove Programs. After uninstalling it from Control Panel, do go to check whether it's completely removed or not. Adobe has some specific files in the folder C:\Program Files\. If you find them, that means you haven't conducted a clean Adobe removal yet.

Last edited by Kunal : 18-01-2011 at 10:48 AM. Reason: External Linking is not allowed
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