/* Write a VIPS image to PNG.
*/
static int
write_vips( Write *write,
int compress, int interlace, const char *profile,
VipsForeignPngFilter filter, gboolean strip )
{
VipsImage *in = write->in;
int bit_depth;
int color_type;
int interlace_type;
int i, nb_passes;
g_assert( in->BandFmt == VIPS_FORMAT_UCHAR ||
in->BandFmt == VIPS_FORMAT_USHORT );
g_assert( in->Coding == VIPS_CODING_NONE );
g_assert( in->Bands > 0 && in->Bands < 5 );
/* Catch PNG errors.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );
/* Check input image. If we are writing interlaced, we need to make 7
* passes over the image. We advertise ourselves as seq, so to ensure
* we only suck once from upstream, switch to WIO.
*/
if( interlace ) {
if( !(write->memory = vips_image_copy_memory( in )) )
return( -1 );
in = write->memory;
}
else {
if( vips_image_pio_input( in ) )
return( -1 );
}
if( compress < 0 || compress > 9 ) {
vips_error( "vips2png",
"%s", _( "compress should be in [0,9]" ) );
return( -1 );
}
/* Set compression parameters.
*/
png_set_compression_level( write->pPng, compress );
/* Set row filter.
*/
png_set_filter( write->pPng, 0, filter );
bit_depth = in->BandFmt == VIPS_FORMAT_UCHAR ? 8 : 16;
switch( in->Bands ) {
case 1: color_type = PNG_COLOR_TYPE_GRAY; break;
case 2: color_type = PNG_COLOR_TYPE_GRAY_ALPHA; break;
case 3: color_type = PNG_COLOR_TYPE_RGB; break;
case 4: color_type = PNG_COLOR_TYPE_RGB_ALPHA; break;
default:
vips_error( "vips2png",
_( "can't save %d band image as png" ), in->Bands );
return( -1 );
}
interlace_type = interlace ? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE;
png_set_IHDR( write->pPng, write->pInfo,
in->Xsize, in->Ysize, bit_depth, color_type, interlace_type,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT );
/* Set resolution. libpng uses pixels per meter.
*/
png_set_pHYs( write->pPng, write->pInfo,
VIPS_RINT( in->Xres * 1000 ), VIPS_RINT( in->Yres * 1000 ),
PNG_RESOLUTION_METER );
/* Set ICC Profile.
*/
if( profile &&
!strip ) {
if( strcmp( profile, "none" ) != 0 ) {
void *data;
size_t length;
if( !(data = vips__file_read_name( profile,
VIPS_ICC_DIR, &length )) )
return( -1 );
#ifdef DEBUG
printf( "write_vips: "
"attaching %zd bytes of ICC profile\n",
length );
#endif /*DEBUG*/
png_set_iCCP( write->pPng, write->pInfo, "icc",
PNG_COMPRESSION_TYPE_BASE, data, length );
}
}
else if( vips_image_get_typeof( in, VIPS_META_ICC_NAME ) &&
!strip ) {
void *data;
size_t length;
if( vips_image_get_blob( in, VIPS_META_ICC_NAME,
&data, &length ) )
return( -1 );
#ifdef DEBUG
printf( "write_vips: attaching %zd bytes of ICC profile\n",
length );
#endif /*DEBUG*/
png_set_iCCP( write->pPng, write->pInfo, "icc",
PNG_COMPRESSION_TYPE_BASE, data, length );
}
png_write_info( write->pPng, write->pInfo );
/* If we're an intel byte order CPU and this is a 16bit image, we need
* to swap bytes.
*/
if( bit_depth > 8 && !vips_amiMSBfirst() )
png_set_swap( write->pPng );
if( interlace )
nb_passes = png_set_interlace_handling( write->pPng );
else
nb_passes = 1;
/* Write data.
*/
for( i = 0; i < nb_passes; i++ )
if( vips_sink_disc( in, write_png_block, write ) )
return( -1 );
/* The setjmp() was held by our background writer: reset it.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );
png_write_end( write->pPng, write->pInfo );
return( 0 );
}
INTMASK *
im_vips2imask( IMAGE *in, const char *filename )
{
int width, height;
INTMASK *out;
double *data;
int x, y;
double double_result;
int int_result;
/* double* only: cast if necessary.
*/
if( in->BandFmt != IM_BANDFMT_DOUBLE ) {
IMAGE *t;
if( !(t = im_open( "im_vips2imask", "p" )) )
return( NULL );
if( im_clip2fmt( in, t, IM_BANDFMT_DOUBLE ) ||
!(out = im_vips2imask( t, filename )) ) {
im_close( t );
return( NULL );
}
im_close( t );
return( out );
}
/* Check the image.
*/
if( im_incheck( in ) ||
im_check_uncoded( "im_vips2imask", in ) )
return( NULL );
if( in->Bands == 1 ) {
width = in->Xsize;
height = in->Ysize;
}
else if( in->Xsize == 1 ) {
width = in->Bands;
height = in->Ysize;
}
else if( in->Ysize == 1 ) {
width = in->Xsize;
height = in->Bands;
}
else {
im_error( "im_vips2imask",
"%s", _( "one band, nx1, or 1xn images only" ) );
return( NULL );
}
data = (double *) in->data;
if( !(out = im_create_imask( filename, width, height )) )
return( NULL );
/* We want to make an intmask which has the same input to output ratio
* as the double image.
*
* Imagine convolving with the double image, what's the ratio of
* brightness between input and output? We want the same ratio for the
* int version, if we can.
*
* Imaging an input image where every pixel is 1, what will the output
* be?
*/
double_result = 0;
for( y = 0; y < height; y++ )
for( x = 0; x < width; x++ )
double_result += data[x + width * y];
double_result /= vips_image_get_scale( in );
for( y = 0; y < height; y++ )
for( x = 0; x < width; x++ )
if( in->Bands > 1 && in->Ysize == 1 )
/* Need to transpose: the image is RGBRGBRGB,
* we need RRRGGGBBB.
*/
out->coeff[x + y * width] =
VIPS_RINT( data[x * height + y] );
else
out->coeff[x + y * width] =
VIPS_RINT( data[x + y * width] );
out->scale = VIPS_RINT( vips_image_get_scale( in ) );
if( out->scale == 0 )
out->scale = 1;
out->offset = VIPS_RINT( vips_image_get_offset( in ) );
/* Now convolve a 1 everywhere image with the int version we've made,
* what do we get?
*/
int_result = 0;
for( y = 0; y < height; y++ )
for( x = 0; x < width; x++ )
int_result += out->coeff[x + width * y];
int_result /= out->scale;
/* And adjust the scale to get as close to a match as we can.
*/
out->scale = VIPS_RINT( out->scale + (int_result - double_result) );
if( out->scale == 0 )
out->scale = 1;
return( out );
}
/* Write a VIPS image to PNG.
*/
static int
write_vips( Write *write, int compress, int interlace )
{
VipsImage *in = write->in;
int bit_depth;
int color_type;
int interlace_type;
int i, nb_passes;
g_assert( in->BandFmt == VIPS_FORMAT_UCHAR ||
in->BandFmt == VIPS_FORMAT_USHORT );
g_assert( in->Coding == VIPS_CODING_NONE );
g_assert( in->Bands > 0 && in->Bands < 5 );
/* Catch PNG errors.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );
/* Check input image.
*/
if( vips_image_pio_input( in ) )
return( -1 );
if( compress < 0 || compress > 9 ) {
vips_error( "vips2png",
"%s", _( "compress should be in [0,9]" ) );
return( -1 );
}
/* Set compression parameters.
*/
png_set_compression_level( write->pPng, compress );
bit_depth = in->BandFmt == VIPS_FORMAT_UCHAR ? 8 : 16;
switch( in->Bands ) {
case 1: color_type = PNG_COLOR_TYPE_GRAY; break;
case 2: color_type = PNG_COLOR_TYPE_GRAY_ALPHA; break;
case 3: color_type = PNG_COLOR_TYPE_RGB; break;
case 4: color_type = PNG_COLOR_TYPE_RGB_ALPHA; break;
default:
g_assert( 0 );
/* Keep -Wall happy.
*/
return( 0 );
}
interlace_type = interlace ? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE;
png_set_IHDR( write->pPng, write->pInfo,
in->Xsize, in->Ysize, bit_depth, color_type, interlace_type,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT );
/* Set resolution. libpnbg uses pixels per meter.
*/
png_set_pHYs( write->pPng, write->pInfo,
VIPS_RINT( in->Xres * 1000 ), VIPS_RINT( in->Yres * 1000 ),
PNG_RESOLUTION_METER );
/* Set ICC Profile.
*/
if( vips_image_get_typeof( in, VIPS_META_ICC_NAME ) ) {
void *profile;
size_t profile_length;
if( vips_image_get_blob( in, VIPS_META_ICC_NAME,
&profile, &profile_length ) )
return( -1 );
#ifdef DEBUG
printf( "write_vips: attaching %zd bytes of ICC profile\n",
profile_length );
#endif /*DEBUG*/
png_set_iCCP( write->pPng, write->pInfo, "icc",
PNG_COMPRESSION_TYPE_BASE, profile, profile_length );
}
png_write_info( write->pPng, write->pInfo );
/* If we're an intel byte order CPU and this is a 16bit image, we need
* to swap bytes.
*/
if( bit_depth > 8 && !vips_amiMSBfirst() )
png_set_swap( write->pPng );
if( interlace )
nb_passes = png_set_interlace_handling( write->pPng );
else
nb_passes = 1;
/* Write data.
*/
for( i = 0; i < nb_passes; i++ )
if( vips_sink_disc( write->in, write_png_block, write ) )
return( -1 );
/* The setjmp() was held by our background writer: reset it.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );
png_write_end( write->pPng, write->pInfo );
return( 0 );
}
/* Make a fixed-point version of a matrix. Each
* out[i] = rint(in[i] * adj_scale), where adj_scale is selected so that
* sum(out) = sum(in) * scale.
*
* Because of the vagaries of rint(), we can't just calc this, we have to
* iterate and converge on the best value for adj_scale.
*/
void
vips_vector_to_fixed_point( double *in, int *out, int n, int scale )
{
double fsum;
int i;
int target;
int sum;
double high;
double low;
double guess;
fsum = 0.0;
for( i = 0; i < n; i++ )
fsum += in[i];
target = VIPS_RINT( fsum * scale );
/* As we rint() each scale element, we can get up to 0.5 error.
* Therefore, by the end of the mask, we can be off by up to n/2. Our
* high and low guesses are therefore n/2 either side of the obvious
* answer.
*/
high = scale + (n + 1) / 2;
low = scale - (n + 1) / 2;
do {
guess = (high + low) / 2.0;
for( i = 0; i < n; i++ )
out[i] = VIPS_RINT( in[i] * guess );
sum = 0;
for( i = 0; i < n; i++ )
sum += out[i];
if( sum == target )
break;
if( sum < target )
low = guess;
if( sum > target )
high = guess;
/* This will typically produce about 5 iterations.
*/
} while( high - low > 0.01 );
if( sum != target ) {
/* Spread the error out thinly over the whole array. For
* example, consider the matrix:
*
* 3 3 9 0
* 1 1 1
* 1 1 1
* 1 1 1
*
* being converted with scale = 64 (convi does this). We want
* to generate a mix of 7s and 8s.
*/
int each_error = (target - sum) / n;
int extra_error = (target - sum) % n;
/* To share the residual error, we add or subtract 1 from the
* first abs(extra_error) elements.
*/
int direction = extra_error > 0 ? 1 : -1;
int n_elements = VIPS_ABS( extra_error );
for( i = 0; i < n; i++ )
out[i] += each_error;
for( i = 0; i < n_elements; i++ )
out[i] += direction;
}
}
/* Write a VIPS image to PNG.
*/
static int
write_vips( Write *write,
int compress, int interlace, const char *profile,
VipsForeignPngFilter filter, gboolean strip,
gboolean palette, int colours, int Q, double dither )
{
VipsImage *in = write->in;
int bit_depth;
int color_type;
int interlace_type;
int i, nb_passes;
g_assert( in->BandFmt == VIPS_FORMAT_UCHAR ||
in->BandFmt == VIPS_FORMAT_USHORT );
g_assert( in->Coding == VIPS_CODING_NONE );
g_assert( in->Bands > 0 && in->Bands < 5 );
/* Catch PNG errors.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );
/* Check input image. If we are writing interlaced, we need to make 7
* passes over the image. We advertise ourselves as seq, so to ensure
* we only suck once from upstream, switch to WIO.
*/
if( interlace ) {
if( !(write->memory = vips_image_copy_memory( in )) )
return( -1 );
in = write->memory;
}
else {
if( vips_image_pio_input( in ) )
return( -1 );
}
if( compress < 0 || compress > 9 ) {
vips_error( "vips2png",
"%s", _( "compress should be in [0,9]" ) );
return( -1 );
}
/* Set compression parameters.
*/
png_set_compression_level( write->pPng, compress );
/* Set row filter.
*/
png_set_filter( write->pPng, 0, filter );
bit_depth = in->BandFmt == VIPS_FORMAT_UCHAR ? 8 : 16;
switch( in->Bands ) {
case 1: color_type = PNG_COLOR_TYPE_GRAY; break;
case 2: color_type = PNG_COLOR_TYPE_GRAY_ALPHA; break;
case 3: color_type = PNG_COLOR_TYPE_RGB; break;
case 4: color_type = PNG_COLOR_TYPE_RGB_ALPHA; break;
default:
vips_error( "vips2png",
_( "can't save %d band image as png" ), in->Bands );
return( -1 );
}
#ifdef HAVE_IMAGEQUANT
/* Enable image quantisation to paletted 8bpp PNG if colours is set.
*/
if( palette ) {
g_assert( colours >= 2 &&
colours <= 256 );
bit_depth = 8;
color_type = PNG_COLOR_TYPE_PALETTE;
}
#else
if( palette )
g_warning( "%s",
_( "ignoring palette (no quantisation support)" ) );
#endif /*HAVE_IMAGEQUANT*/
interlace_type = interlace ? PNG_INTERLACE_ADAM7 : PNG_INTERLACE_NONE;
png_set_IHDR( write->pPng, write->pInfo,
in->Xsize, in->Ysize, bit_depth, color_type, interlace_type,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT );
/* Set resolution. libpng uses pixels per meter.
*/
png_set_pHYs( write->pPng, write->pInfo,
VIPS_RINT( in->Xres * 1000 ), VIPS_RINT( in->Yres * 1000 ),
PNG_RESOLUTION_METER );
/* Set ICC Profile.
*/
if( profile &&
!strip ) {
if( strcmp( profile, "none" ) != 0 ) {
void *data;
size_t length;
if( !(data = vips__file_read_name( profile,
vips__icc_dir(), &length )) )
return( -1 );
#ifdef DEBUG
printf( "write_vips: "
"attaching %zd bytes of ICC profile\n",
length );
#endif /*DEBUG*/
png_set_iCCP( write->pPng, write->pInfo, "icc",
PNG_COMPRESSION_TYPE_BASE, data, length );
}
}
else if( vips_image_get_typeof( in, VIPS_META_ICC_NAME ) &&
!strip ) {
void *data;
size_t length;
if( vips_image_get_blob( in, VIPS_META_ICC_NAME,
&data, &length ) )
return( -1 );
#ifdef DEBUG
printf( "write_vips: attaching %zd bytes of ICC profile\n",
length );
#endif /*DEBUG*/
png_set_iCCP( write->pPng, write->pInfo, "icc",
PNG_COMPRESSION_TYPE_BASE, data, length );
}
if( vips_image_get_typeof( in, VIPS_META_XMP_NAME ) ) {
const char *str;
if( vips_image_get_string( in, VIPS_META_XMP_NAME, &str ) )
return( -1 );
vips__png_set_text( write->pPng, write->pInfo,
"XML:com.adobe.xmp", str );
}
/* Set any "png-comment-xx-yyy" metadata items.
*/
if( vips_image_map( in,
write_png_comment, write ) )
return( -1 );
#ifdef HAVE_IMAGEQUANT
if( palette ) {
VipsImage *im_index;
VipsImage *im_palette;
int palette_count;
png_color *png_palette;
png_byte *png_trans;
int trans_count;
if( vips__quantise_image( in, &im_index, &im_palette,
colours, Q, dither ) )
return( -1 );
palette_count = im_palette->Xsize;
g_assert( palette_count <= PNG_MAX_PALETTE_LENGTH );
png_palette = (png_color *) png_malloc( write->pPng,
palette_count * sizeof( png_color ) );
png_trans = (png_byte *) png_malloc( write->pPng,
palette_count * sizeof( png_byte ) );
trans_count = 0;
for( i = 0; i < palette_count; i++ ) {
VipsPel *p = (VipsPel *)
VIPS_IMAGE_ADDR( im_palette, i, 0 );
png_color *col = &png_palette[i];
col->red = p[0];
col->green = p[1];
col->blue = p[2];
png_trans[i] = p[3];
if( p[3] != 255 )
trans_count = i + 1;
#ifdef DEBUG
printf( "write_vips: palette[%d] %d %d %d %d\n",
i + 1, p[0], p[1], p[2], p[3] );
#endif /*DEBUG*/
}
#ifdef DEBUG
printf( "write_vips: attaching %d color palette\n",
palette_count );
#endif /*DEBUG*/
png_set_PLTE( write->pPng, write->pInfo, png_palette,
palette_count );
if( trans_count ) {
#ifdef DEBUG
printf( "write_vips: attaching %d alpha values\n",
trans_count );
#endif /*DEBUG*/
png_set_tRNS( write->pPng, write->pInfo, png_trans,
trans_count, NULL );
}
png_free( write->pPng, (void *) png_palette );
png_free( write->pPng, (void *) png_trans );
VIPS_UNREF( im_palette );
VIPS_UNREF( write->memory );
write->memory = im_index;
in = write->memory;
}
#endif /*HAVE_IMAGEQUANT*/
png_write_info( write->pPng, write->pInfo );
/* If we're an intel byte order CPU and this is a 16bit image, we need
* to swap bytes.
*/
if( bit_depth > 8 &&
!vips_amiMSBfirst() )
png_set_swap( write->pPng );
if( interlace )
nb_passes = png_set_interlace_handling( write->pPng );
else
nb_passes = 1;
/* Write data.
*/
for( i = 0; i < nb_passes; i++ )
if( vips_sink_disc( in, write_png_block, write ) )
return( -1 );
/* The setjmp() was held by our background writer: reset it.
*/
if( setjmp( png_jmpbuf( write->pPng ) ) )
return( -1 );
png_write_end( write->pPng, write->pInfo );
return( 0 );
}
