How Huffman Encoding construct the image(jpeg) from dct coefficients?

Question

I have a 512x512 image and I tried to recompress it. Here's the steps for recompressing an image to jpeg file

    1) convert rgb to YCrCb
    2) perform down sampling on Cr and Cb
    2) convert YCrCb to DCT and Quantized according to chosen Quality
    3) perform Huffman Encoding on Quantized DCT

But before Huffman Encoding I counted the number of DCT coefficients and it is 393216. Dividing by it by 64 tells me the number of DCT block (8x8) which will be 6144.

Now I tried to count the number of 8x8 blocks for pixel domain. 512/8=64 which gives me 64 blocks horizontally and 64 blocks vertically. 64 x 64 = 4096 which is not equal to number of DCT blocks while the number of pixels are 512x512 = 262144

My Question is how does Huffman encoding magically transform 393216 coefficients to 262144 pixels and get each pixel values, and compute the dimension (512x512) of the compressed image(jpeg).

Thanks you in advance. :D