I finished a saver operation for floating point npy images. It may e.g. be used to debug floating point operations (e.g. gaussian-blur) with numerical python. The resulting image may be read into numpy as follows:
import numpy
img = numpy.load('image.npy')
It may also be viewed in my image viewer giv (though it currently does not support color npy images).
Is it ok to commit it?
Follows the code.
Regards,
Dov
/* This file is an image processing operation for GEGL
*
* GEGL is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* GEGL is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
*
* Copyright Dov Grobgeld 2013 <dov.grobgeld (a) gmail.com>
*
* This operation saves a buffer in the npy file format. It may be
* read into python as follows:
*
* import numpy
* img = numpy.load('image.npy')
*/
#include "config.h"
#include <glib/gi18n-lib.h>
#ifdef GEGL_CHANT_PROPERTIES
gegl_chant_string (path, _("File"), "",
_("Target path and filename, use '-' for stdout."))
#else
#define GEGL_CHANT_TYPE_SINK
#define GEGL_CHANT_C_FILE "npy-save.c"
#include "gegl-chant.h"
#include <stdio.h>
static int npywrite(FILE *fp, guchar *data, int width, int height, int num_channels)
{
char header[100];
unsigned short header_len;
// Write header and version number to file
fwrite("\223NUMPY"
"\001\000"
, 1, 8, fp);
if (num_channels == 3)
sprintf(header,
"{'descr': '<f4', 'fortran_order': False, 'shape': (%d, %d, 3), } \n",
height, width);
else
sprintf(header,
"{'descr': '<f4', 'fortran_order': False, 'shape': (%d, %d), } \n",
height, width);
header_len = strlen(header);
fwrite(&header_len, 2, 1, fp);
fwrite(header, header_len, 1, fp);
fwrite(data, width*height*num_channels, sizeof(float), fp);
return 0;
}
static gboolean
process (GeglOperation *operation,
GeglBuffer *input,
const GeglRectangle *rect,
gint level)
{
GeglChantO *o = GEGL_CHANT_PROPERTIES (operation);
FILE *fp;
guchar *data;
gsize bpc;
gsize numsamples;
gsize numchannels;
gboolean ret = FALSE;
const Babl *output_format;
const Babl *input_format = gegl_buffer_get_format(input);
// Get the current format and use it to decide whether to save
// the output in color or gray level formats.
bpc = sizeof(gfloat);
if (babl_format_get_n_components(input_format) >= 3)
{
numchannels = 3;
output_format = babl_format("RGB float");
}
else
{
numchannels = 1;
output_format = babl_format ("Y float");
}
numsamples = rect->width * rect->height * numchannels;
data = "" (numsamples * bpc);
gegl_buffer_get (input, rect, 1.0, output_format, data,
GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
fp = (!strcmp (o->path, "-") ? stdout : fopen(o->path, "wb") );
npywrite(fp, data, rect->width, rect->height, numchannels);
g_free (data);
return ret;
}
static void
gegl_chant_class_init (GeglChantClass *klass)
{
GeglOperationClass *operation_class;
GeglOperationSinkClass *sink_class;
operation_class = GEGL_OPERATION_CLASS (klass);
sink_class = GEGL_OPERATION_SINK_CLASS (klass);
sink_class->process = process;
sink_class->needs_full = TRUE;
gegl_operation_class_set_keys (operation_class,
"name" , "gegl:npy-save",
"categories" , "output",
"description" ,
_("NPY image saver (Numerical python file saver.)"),
NULL);
gegl_extension_handler_register_saver (".npy", "gegl:npy-save");
}
#endif
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