reset password
Author Message
FuneralDepression
Posts: 10
Posted 23:53 Apr 21, 2020 |

what is the "n" in DCT part of the homework, i know its the compression value, but what exactly does this do?

yzhao52
Posts: 32
Posted 15:16 Apr 22, 2020 |

The varibale n in task 2 is not the compression ratio. It's the quality control parameter, which is used to adjust the quantization table in page 5. 

306118636
Posts: 1
Posted 02:15 Apr 24, 2020 |

I dont really get the n. if the n = 0 we leave the table 1 and table 2 alone. if n = 1 we are going to double the values in table 1 and table 2. 

Than the chrome boolean value is whether we use the normal or double?

yzhao52
Posts: 32
Posted 14:10 Apr 24, 2020 |
306118636 wrote:

I dont really get the n. if the n = 0 we leave the table 1 and table 2 alone. if n = 1 we are going to double the values in table 1 and table 2. 

Than the chrome boolean value is whether we use the normal or double?

We have two different quantization tables, one for Y and one for Cb/Cr. The Boolean variable chroma select which table to use: false means using luminance table for Y and true means using chrominance table for Cb/Cr.