NAME

ilGetBytesPerRow() − return the number of bytes required to hold one image scan line

SYNOPSIS

void
ilGetBytesPerRow (

ilImageDes *pDes,

ilImageFormat *pDes,

long width

long *pnBytesPerRow);

DESCRIPTION

ilGetBytesPerRow() returns the number of bytes required to hold one scan line of an image. 

*pDes points to a descriptor of the image. 

*pFormat points to the format of the image. 

width is the width in pixels of one scan line of the image

*pNBytesPerRow
receives an array of IL_MAX_SAMPLES long where the minimum scan line width, in bytes, is returned for each plane.  If pFormat->sampleOrder is IL_SAMPLE_PIXELS, there is one plane of data, and on return *pNBytesPerRow will contain the minimum length of each scan line in bytes.  If pFormat->sampleOrder is IL_SAMPLE_PLANES, there are pDes->nSamplesPerPixels planes, and pNBytesPerRow[i] will contain the byte length for each plane "i" where "i" ranges from 0 to pDes->nSamplesPerPixels - 1. 

RETURN VALUE

ilGetBytesPerRow() has no return value. 

ERRORS

If the call fails, context->error receives a non-zero error code. 

EXAMPLE

The following example returns in the variable numBytes the number of bytes required to hold one scan line of a YCbCr, plane oriented image that is 640 pixels wide. 

long rowBytesPerPlane [IL_MAX_SAMPLES];
.
.
.

/∗  Get the bytes per row ∗/

if (!ilGetBytesPerRow (IL_DES_YCBCR_2, IL_FORMAT_3BYTE_PLANE,

640, rowBytesPerPlane)) return(context->error);

AUTHOR

ilGetBytesPerRow() was developed by HP. 

SEE ALSO

ilImageDes(3X), ilImageFormat(3X), ilerror(3X). 

Using the Image Developer’s Kit.

Hewlett-Packard Company  —  Image Library: February, 1995