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/*
* jcexpand.c
*
* Copyright (C) 1991, 1992, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains image edge-expansion routines.
* These routines are invoked via the edge_expand method.
*/
#include "jinclude.h"
/*
* Expand an image so that it is a multiple of the MCU dimensions.
* This is to be accomplished by duplicating the rightmost column
* and/or bottommost row of pixels. The image has not yet been
* downsampled, so all components have the same dimensions.
*/
METHODDEF void
edge_expand (compress_info_ptr cinfo,
long input_cols, int input_rows,
long output_cols, int output_rows,
JSAMPIMAGE image_data)
{
/* Expand horizontally */
if (input_cols < output_cols) {
register JSAMPROW ptr;
register JSAMPLE pixval;
register long count;
register int row;
short ci;
long numcols = output_cols - input_cols;
for (ci = 0; ci < cinfo->num_components; ci++) {
for (row = 0; row < input_rows; row++) {
ptr = image_data[ci][row] + (input_cols-1);
pixval = GETJSAMPLE(*ptr++);
for (count = numcols; count > 0; count--)
*ptr++ = pixval;
}
}
}
/* Expand vertically */
/* This happens only once at the bottom of the image, */
/* so it needn't be super-efficient */
if (input_rows < output_rows) {
register int row;
short ci;
JSAMPARRAY this_component;
for (ci = 0; ci < cinfo->num_components; ci++) {
this_component = image_data[ci];
for (row = input_rows; row < output_rows; row++) {
jcopy_sample_rows(this_component, input_rows-1, this_component, row,
1, output_cols);
}
}
}
}
/*
* The method selection routine for edge expansion.
*/
GLOBAL void
jselexpand (compress_info_ptr cinfo)
{
/* just one implementation for now */
cinfo->methods->edge_expand = edge_expand;
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.