17-11-2021, 10:11 PM
I have noticed that when a cross hatch is converted from 625 to 405 some of the horizontal lines can flicker. This will depend on where the 405 line is positioned between the 625 lines.
The test card in the Hedghog is a field that is repeated twice to make up the frame. Each horizontal line is made from one horizontal in each field.
The test card in the Hedghog II is similar except the center horizontal line is made up from lines taken from opposite fields than all the other horizontal lines in the test card. It is difficult to explain the illustration below might help.
I believe that the center line is done that way in the PM5544 test card.
I read somewhere that it is supposed to help show up interlace problems.
Frank
The test card in the Hedghog is a field that is repeated twice to make up the frame. Each horizontal line is made from one horizontal in each field.
The test card in the Hedghog II is similar except the center horizontal line is made up from lines taken from opposite fields than all the other horizontal lines in the test card. It is difficult to explain the illustration below might help.
I believe that the center line is done that way in the PM5544 test card.
I read somewhere that it is supposed to help show up interlace problems.
Frank
