function [ Rate, SNR ] = mComputeDCT8x8RateAndSNR( image, weight_scale )

image_size = prod( size( image ) );

image_mean = round( mean(mean(image)) );

M = 8;

[ reconstructed_image, quantized_coefficients ] = mOptimalDCT8x8ImageAndCoeffs( image, weight_scale );

signal = mean( mean( image.^2 ) );
noise  = mean( mean( (image-reconstructed_image).^2 ) );

SNR = 10*log10( signal/noise );

[ PDF_update range_update RLE_count RLE_update ] = mComputeRLEPDF( quantized_coefficients, 1, M );

% x*log(x) = log(x^x)
PlogP = log( PDF_update.^PDF_update)./log(2);
Rate = -sum(sum( PlogP' ))*RLE_count/image_size;