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Andrew Russell
Andrew Russell
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Obviously: It depends on the format.

Let's take a 256 by 256 pixel square texture. If it's uncompressed 32-bit with an alpha channel (Color in XNA) then it takes 256KB (256*256*4 bytes).

16-bit formats (eg: Bgr565) will obviously be half the size (- 128KB).

Then you get onto the compressed formats. In XNA you have DXT1, DXT3 and DXT5 (also known as S3 Compression). This is a lossy compression format. It is also a block-based format - which means that you can sample from it (because you know which block a pixel is in). It's also faster, because you use less bandwidth.

The compression ratio of DXT1 is 8:1 and for DXT3 and DXT5 is 4:1.

So a DXT1 image of 256x256 is 32KB. And DXT3 or DXT5 is 64KB.

And then there's mipmapping. If this is enabled, this creates a series of images in graphics memory each half the size of the previous. So for our 256x256 image: 128x128, 64x64, 32x32, 16x16, 8x8, 4x4, 2x2, 1x1. A texture with mipmapping is approximately 133% the size of the original.

Obviously: It depends on the format.

Let's take a 256 by 256 pixel square texture. If it's uncompressed 32-bit with an alpha channel (Color in XNA) then it takes 256KB (256*256*4 bytes).

16-bit formats (eg: Bgr565) will obviously be half the size (128KB)

Then you get onto the compressed formats. In XNA you have DXT1, DXT3 and DXT5 (also known as S3 Compression). This is a lossy compression format. It is also a block-based format - which means that you can sample from it (because you know which block a pixel is in). It's also faster, because you use less bandwidth.

The compression ratio of DXT1 is 8:1 and for DXT3 and DXT5 is 4:1.

So a DXT1 image of 256x256 is 32KB. And DXT3 or DXT5 is 64KB.

And then there's mipmapping. If this is enabled, this creates a series of images in graphics memory each half the size of the previous. So for our 256x256 image: 128x128, 64x64, 32x32, 16x16, 8x8, 4x4, 2x2, 1x1. A texture with mipmapping is 133% the size of the original.

Obviously: It depends on the format.

Let's take a 256 by 256 pixel square texture. If it's uncompressed 32-bit with an alpha channel (Color in XNA) then it takes 256KB (256*256*4 bytes).

16-bit formats (eg: Bgr565) will obviously be half the size - 128KB.

Then you get onto the compressed formats. In XNA you have DXT1, DXT3 and DXT5 (also known as S3 Compression). This is a lossy compression format. It is also a block-based format - which means that you can sample from it (because you know which block a pixel is in). It's also faster, because you use less bandwidth.

The compression ratio of DXT1 is 8:1 and for DXT3 and DXT5 is 4:1.

So a DXT1 image of 256x256 is 32KB. And DXT3 or DXT5 is 64KB.

And then there's mipmapping. If this is enabled, this creates a series of images in graphics memory each half the size of the previous. So for our 256x256 image: 128x128, 64x64, 32x32, 16x16, 8x8, 4x4, 2x2, 1x1. A texture with mipmapping is approximately 133% the size of the original.

Source Link
Andrew Russell
Andrew Russell
  • 21.3k
  • 7
  • 57
  • 103

Obviously: It depends on the format.

Let's take a 256 by 256 pixel square texture. If it's uncompressed 32-bit with an alpha channel (Color in XNA) then it takes 256KB (256*256*4 bytes).

16-bit formats (eg: Bgr565) will obviously be half the size (128KB)

Then you get onto the compressed formats. In XNA you have DXT1, DXT3 and DXT5 (also known as S3 Compression). This is a lossy compression format. It is also a block-based format - which means that you can sample from it (because you know which block a pixel is in). It's also faster, because you use less bandwidth.

The compression ratio of DXT1 is 8:1 and for DXT3 and DXT5 is 4:1.

So a DXT1 image of 256x256 is 32KB. And DXT3 or DXT5 is 64KB.

And then there's mipmapping. If this is enabled, this creates a series of images in graphics memory each half the size of the previous. So for our 256x256 image: 128x128, 64x64, 32x32, 16x16, 8x8, 4x4, 2x2, 1x1. A texture with mipmapping is 133% the size of the original.