NAME

ilEFSGetPageInfo() − return information on the current page

SYNOPSIS

ilBool
ilEFSGetPageInfo (

ilEFSFile file,

ilEFSPageInfo *pInfo );

DESCRIPTION

ilEFSGetPageInfo() returns information on the current page, which is the next page to be read in the file. 

Note that because the pages in a file can be different, no guarantee exists that one page size, resolution, or image type is used throughout the file.  For example, one file could contain both a bitonal page and a color page. 

file is a file opened with an openMode of IL_EFS_READ or IL_EFS_READ_SEQUENTIAL. 

*pInfo receives the contents of an ilEFSPageInfo structure, which contains the following fields:

attributes is a bit set of attributes for the page.  The following masks are defined

IL_EFS_EOF
indicates the page is at the End Of File (EOF).  In other words, no pages remain to be read and subsequently returned data is undefined. Note that only file types that support multi-page reads should set this bit; single-page file types are never at the end of file, because ilEFSReadImage() always reads the first and only image. 

IL_EFS_MASKED
indicates the current page has a mask image.

IL_EFS_SCALEABLE
indicates the current page is scaleable.

page is the current page number, with page zero (0) being the first page in the file. 

width, height are the size of the page (image) in pixels.  If the page is scaleable (attributes & IL_EFS_SCALEABLE), this size is the default size; an image of a different size may be read.  See ilEFSReadImage(3X) for details. 

xRes,yRes are the X and Y resolution of the image in dots per inch (dpi) times two (2).  For example, xRes is 150 for the image that has a horizontal resolution of 75 dpi.  xRes and yRes are both zero (0) if the file has no resolution information.  If the page is scaleable, xRes and yRes indicate the resolution based on the default width and height. 

des is the descriptor for the page image. 

format is the format of the page image. 

RETURN VALUE

Upon successful completion, ilEFSGetPageInfo() returns TRUE. 

ERRORS

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

AUTHOR

ilEFSGetPageInfo() was developed by HP. 

SEE ALSO

ilEFSReadImage(3X), ilEFSOpen(3X), ilerror(3X). 

Using the Image Developer’s Kit.
 

Hewlett-Packard Company  —  Image Library: February, 1995