where does the extra noise originate from? is it being blurred from the compression and originates from the black pixels of the a or something else?
ronthalanki
JPEG compression wouldn't be a good compression scheme for line-based illustrations since JPEG stores pixel data and most resolutions this would be encoding unnecessary data since storing the equations of the lines that represent the text would require significantly less data.
ja5087
Is it correct to say that lines and texts are high frequency content, which JPEG is bad at representing?
gkimball1
With line-based illustrations or other images with sudden sharp changes, JPEG compression loses quality due to its DCT (frequency-based) encoding scheme. Since sudden sharp changes in space correspond to the presence of a broad spectrum of frequencies, pruning some frequencies out in the interest of compression--as JPEG does--will often result in the loss of significant information, causing noise artifacts as demonstrated here.
where does the extra noise originate from? is it being blurred from the compression and originates from the black pixels of the a or something else?
JPEG compression wouldn't be a good compression scheme for line-based illustrations since JPEG stores pixel data and most resolutions this would be encoding unnecessary data since storing the equations of the lines that represent the text would require significantly less data.
Is it correct to say that lines and texts are high frequency content, which JPEG is bad at representing?
With line-based illustrations or other images with sudden sharp changes, JPEG compression loses quality due to its DCT (frequency-based) encoding scheme. Since sudden sharp changes in space correspond to the presence of a broad spectrum of frequencies, pruning some frequencies out in the interest of compression--as JPEG does--will often result in the loss of significant information, causing noise artifacts as demonstrated here.