Posted on February 1, 2023 (Updated on July 10, 2025)

Why does an 32-bit FGDB raster have a smaller file size than 8-bit?

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What is pixel depth in raster?

The bit depth (pixel depth) of a pixel determines the range of values that a particular raster file can store, which is based on the formula 2n (where n is the bit depth). For example, an 8-bit raster can have 256 unique values that range from 0 to 255.

What pixel depth is needed to store values with decimal places in Arcgis pro?

If you want to store decimals, you need a 32 bit (or 64bit) floating point data type. The 1-4 bit and signed & unsigned 8-32 bit types listed in that table are integer types.
 

What is the size of raster?

Raster images are of a certain size, such as 800×600 for the sample image above, indicating the image is 800 pixels wide and 600 pixels high. This size affects both the size of the image file and how the image looks on screen or when printed out.

Is bit depth the same as bits per pixel?

The bit depth for each primary color is termed the “number of bits per channel”, typically ranging from 8 to 16bits. The “bits per pixel” (bpp) refers to the sum of the “number of bits per color channel” i.e. the total number of bits required to code the color information of the pixel.
 

How do I change the raster pixel size in ArcGIS?

Resize Rasters

  1. From the Toolbox, select Raster Management > Resize Raster.
  2. Select an input raster and perform optional spatial and/or spectral subsetting, and masking.
  3. Click OK.
  4. Change the output dimensions by setting the Image Size, Resize Factor, or Pixel Size values.

How many bits are required to store a RGB pixel of each pixel has a range from 0 to 255?

8 bits

A picture with less than or equal to 256 colors may be save in BMP format using only 8 bits per pixel. If 0 < number of colors < 16,777,216 BMP uses 24 bits per pixel. JPEG however tends to use 24 bits per pixel regardless of the number of colors stored.

How many bits are required for a pixel?

Each pixel typically consists of 8 bits (1 byte) for a Black and White (B&W) image or 24 bits (3 bytes) for a color image— one byte each for Red, Green, and Blue. 8 bits represents 28 = 256 tonal levels (0-255).

What is meant by pixel depth?

The pixel depth, or bit depth, determines the range of values that a particular raster file can store, which is based on the formula 2^n where n is the pixel depth. For example, an 8-bit raster can have 256 unique values, which range from 0 to 255.
 

What is depth per pixel?

bits per pixel or pixel depth: The number of data bits each pixel represents. In 8-bit contexts, the pixel depth is 8, and each display pixel can be one of 256 possible colors or shades of gray. With a 24-bit raster (or with three coregistered 8-bit rasters) the pixel depth is 24, and 16,777,216 colors are possible.

What determines pixel depth?

BIT DEPTH is determined by the number of bits used to define each pixel. The greater the bit depth, the greater the number of tones (grayscale or color) that can be represented. Digital images may be produced in black and white (bitonal), grayscale, or color.