kc3-lang/libjpeg-turbo/jcexpand.c

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• Hash : 88aeed42
  Author :
  Date : 1992-12-10T00:00:00
  

  The Independent JPEG Group's JPEG software v4
  

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• jcexpand.c

• /*
   * 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;
  }
  

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