Controlling deblocking filtering

A filtering control device comprising:

• a filtering unit configured to filter pixel values of pixels in a line of pixels in a block of pixels with a strong deblocking filter to obtain filtered pixel values;
• and
• a clipping unit configured to clip off, for each filtered pixel value of a pixel in said line of pixels, said filtered pixel value to a respective clipping parameter value defined based on a position of said pixel relative to a block boundary between said block of pixels and a neighboring block of pixels, wherein said clipping parameter values change at least approximately linearly depending on said position of said pixel relative to said block boundary and pixels in said line of pixels having different positions from said block boundary have different clipping parameter values.

A filtering control device comprising a processing unit configured to:

• filter pixel values of pixels in a line of pixels in a block of pixels with a strong deblocking filter to obtain filtered pixel values;
• and
• clip off, for each filtered pixel value of a pixel in said line of pixels, said filtered pixel value to a respective clipping parameter value defined based on a position of said pixel relative to a block boundary between said block of pixels and a neighboring block of pixels, wherein said clipping parameter values change at least approximately linearly depending on said position of said pixel relative to said block boundary and pixels in said line of pixels having different positions from said block boundary have different clipping parameter values.

A computer program for filtering control, said computer program comprises code means which when executed by a processing unit causes said processing unit to:

• filter pixel values of pixels in a line of pixels in a block of pixels with a strong deblocking filter to obtain filtered pixel values;
• and
• clip off, for each filtered pixel value of a pixel in said line of pixels, said filtered pixel value to a respective clipping parameter value defined based on a position of said pixel relative to a block boundary between said block of pixels and a neighboring block of pixels, wherein said clipping parameter values change at least approximately linearly depending on said position of said pixel relative to said block boundary and pixels in said line of pixels having different positions from said block boundary have different clipping parameter values.