mutter/clutter/pixbuf.c
2005-04-27 22:17:45 +00:00

1117 lines
26 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h> /* For memset() */
#include <unistd.h> /* For read() */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h> /* For mmap()/munmap() */
#include <sys/types.h>
#include <png.h>
#include <jpeglib.h>
#include "pixbuf.h"
#include "util.h"
#define CLTR_CLAMP(x, y) ((x) > (y)) ? (y) : (x);
static int*
load_png_file( const char *file,
int *width,
int *height)
{
FILE *fd;
/* GLubyte *data; */
int *data;
unsigned char header[8];
int bit_depth, color_type;
png_uint_32 png_width, png_height, i, rowbytes;
png_structp png_ptr;
png_infop info_ptr;
png_bytep *row_pointers;
if ((fd = fopen( file, "rb" )) == NULL) return NULL;
/* check header etc */
fread(header, 1, 8, fd);
if (!png_check_sig(header, 8))
{
fclose(fd);
return NULL;
}
png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
{
fclose(fd);
return NULL;
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_read_struct( &png_ptr, (png_infopp)NULL, (png_infopp)NULL);
fclose(fd);
return NULL;
}
if (setjmp( png_ptr->jmpbuf ) )
{
png_destroy_read_struct( &png_ptr, &info_ptr, NULL);
fclose(fd);
return NULL;
}
png_init_io( png_ptr, fd );
png_set_sig_bytes( png_ptr, 8);
png_read_info( png_ptr, info_ptr);
png_get_IHDR( png_ptr, info_ptr,
&png_width, &png_height, &bit_depth,
&color_type, NULL, NULL, NULL);
*width = (int) png_width;
*height = (int) png_height;
/* Tranform to req 8888 */
if (bit_depth == 16 ) png_set_strip_16(png_ptr); /* 16 -> 8 */
if (bit_depth < 8) png_set_packing(png_ptr); /* 1,2,4 -> 8 */
if (( color_type == PNG_COLOR_TYPE_GRAY ) ||
( color_type == PNG_COLOR_TYPE_GRAY_ALPHA ))
png_set_gray_to_rgb(png_ptr);
if (( color_type == PNG_COLOR_TYPE_GRAY ) ||
( color_type == PNG_COLOR_TYPE_RGB ))
png_set_add_alpha(png_ptr, 0xff, PNG_FILLER_AFTER); /* req 1.2.7 */
if (( color_type == PNG_COLOR_TYPE_PALETTE )||
( png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS )))
png_set_expand(png_ptr);
png_read_update_info( png_ptr, info_ptr);
/* Now load the actual data */
rowbytes = png_get_rowbytes( png_ptr, info_ptr);
data = (int *) malloc( (rowbytes*(*height + 1)));
row_pointers = (png_bytep *) malloc( (*height)*sizeof(png_bytep));
if (( data == NULL ) || ( row_pointers == NULL ))
{
png_destroy_read_struct( &png_ptr, &info_ptr, NULL);
if (data) free(data);
if (row_pointers) free(row_pointers);
return NULL;
}
for ( i = 0; i < *height; i++ )
row_pointers[i] = (png_bytep) data + i*rowbytes;
png_read_image( png_ptr, row_pointers );
png_read_end( png_ptr, NULL);
free(row_pointers);
png_destroy_read_struct( &png_ptr, &info_ptr, NULL);
fclose(fd);
return data;
}
struct local_error_mgr
{
struct jpeg_error_mgr pub; /* "public" fields */
jmp_buf setjmp_buffer; /* for return to caller */
};
typedef struct local_error_mgr * local_error_ptr;
static void
_jpeg_error_exit (j_common_ptr cinfo)
{
local_error_ptr err = (local_error_ptr) cinfo->err;
(*cinfo->err->output_message) (cinfo);
longjmp(err->setjmp_buffer, 1);
}
static int*
load_jpg_file( const char *file,
int *width,
int *height)
{
struct jpeg_decompress_struct cinfo;
struct local_error_mgr jerr;
FILE *infile; /* source file */
JSAMPLE *buffer; /* Output row buffer */
int row_stride; /* physical row width in output buffer */
int *data = NULL, *d = NULL;
if ((infile = fopen(file, "rb")) == NULL)
return NULL;
cinfo.err = jpeg_std_error(&jerr.pub);
jerr.pub.error_exit = _jpeg_error_exit;
if (setjmp(jerr.setjmp_buffer)) {
jpeg_destroy_decompress(&cinfo);
fclose(infile);
return NULL;
}
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, infile);
jpeg_read_header(&cinfo, TRUE);
cinfo.do_fancy_upsampling = FALSE;
cinfo.do_block_smoothing = FALSE;
cinfo.out_color_space = JCS_RGB;
cinfo.scale_num = 1;
jpeg_start_decompress(&cinfo);
if( cinfo.output_components != 3 )
{
/*
fprintf( stderr, "mbpixbuf: jpegs with %d channles not supported\n",
cinfo.output_components );
*/
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
return NULL;
}
*width = cinfo.output_width;
*height = cinfo.output_height;
d = data = malloc(*width * *height * 4 );
row_stride = cinfo.output_width * cinfo.output_components;
buffer = malloc( sizeof(JSAMPLE)*row_stride );
while (cinfo.output_scanline < cinfo.output_height)
{
int off = 0;
jpeg_read_scanlines(&cinfo, &buffer, 1);
while (off < row_stride)
{
/* XXX Endianess */
*d++ =
(buffer[off] << 24) | /* RGBA */
(buffer[off+1] << 16) |
(buffer[off+2] << 8) |
(0xff << 0);
off += 3;
}
}
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);
if (buffer) free(buffer);
return data;
}
/* X pcx code, based on usplash code by paul coden */
/* http://courses.ece.uiuc.edu/ece390/books/labmanual/graphics-pcx.html */
typedef struct
{
unsigned char manufacturer;
unsigned char version;
unsigned char encoding;
unsigned char bits_per_pixel;
unsigned short xmin;
unsigned short ymin;
unsigned short xmax;
unsigned short ymax;
unsigned short xdpi;
unsigned short ydpi;
unsigned char colourmap[48];
unsigned char reserved;
unsigned char planes;
unsigned short scanline_length;
unsigned short palette_info;
unsigned short xsize;
unsigned short ysize;
unsigned char fill[54];
unsigned char data[0];
} pcx;
enum
{
PCX_ZSOFT = 10,
PCX_RLE = 1,
PCX_WITH_PALETTE = 2,
PCX_COLOUR_MAP_LENGTH = 769
};
/*
** Reads the first 128 bytes of a PCX headers, from an file
** descriptor, into memory.
** RETURN zero on success.
*/
int
pcx_read_header(pcx *header, int fd)
{
if(!lseek(fd, 0, SEEK_SET))
if(read(fd, header, sizeof(pcx)) == sizeof(pcx))
return 0;
return -1;
}
/*
** Does the file descriptor point to a PCX file, which is of a
** suitable colour-depth (8-bit) for us to use?
** RETURN zero on success.
*/
static int
pcx_is_suitable(int fd)
{
pcx header;
if(!pcx_read_header(&header, fd))
if(header.manufacturer == PCX_ZSOFT
/* && header.version >= PCX_WITH_PALETTE && */
&& header.encoding == PCX_RLE
&& header.planes == 3 /* 24bpp */
&& header.bits_per_pixel == 8 ) /* why not 24 from gimp */
return 0;
return -1;
}
/*
** Takes a raw PCX RLE stream and decompresses it into the destination
** buffer, which must be big enough!
** RETURN zero on success
**
** PCX images are RLE (Run Length Encoded as follows:
** if(top two bits are set) // >= 0xc0
** use bottom six bit (& 0x3f) as RLE count for next byte;
** else // < 0xc0
** copy one byte normally;
*/
static void
pcx_raw_decode24(int *dest,
unsigned char *src,
int width,
int height)
{
int x, y, i, count;
int *d = dest;
unsigned char *p;
memset(dest, 0xff, height * width * 4);
for(y = 0; y < height; y++)
{
d = dest + (y * width);
/* RGB */
for(x = 0; x < width;)
if(*src < 0xc0)
{
x++;
p = (unsigned char *)d++;
*p = *src++;
}
else
{
count = *src++ & 0x3f;
for (i=0; i<count; i++)
{
p = (unsigned char *)d++;
*p = *src++;
x += count;
}
}
d = dest + (y * width);
/* RGB */
for(x = 0; x < width;)
if(*src < 0xc0)
{
x++;
p = (unsigned char *)d++;
*(p+1) = *src++;
}
else
{
count = *src++ & 0x3f;
for (i=0; i<count; i++)
{
p = (unsigned char *)d++;
*(p+1) = *src++;
}
x += count;
}
d = dest + (y * width);
/* RGB */
for(x = 0; x < width;)
if(*src < 0xc0)
{
x++;
p = (unsigned char *)d++;
*(p+2) = *src++ ;
}
else
{
count = *src++ & 0x3f;
for (i=0; i<count; i++)
{
p = (unsigned char *)d++;
*(p+2) = *src++;
}
x += count;
}
}
}
int*
load_pcx_file (const char *filename,
int *width,
int *height)
{
int *data;
int fd, file_length;
pcx *header;
struct stat st;
/* Open file */
if((fd = open(filename, O_RDONLY)) < 0)
return NULL;
/* Test file */
if(pcx_is_suitable(fd))
return NULL;
/* Get file size */
if (fstat(fd, &st))
return NULL;
file_length = st.st_size;
/* mmap the pcx file into our header */
header = mmap(NULL, file_length, PROT_READ, MAP_SHARED, fd, 0);
if (header == MAP_FAILED)
return NULL;
/* Get the width and height of the image */
*width = header->xmax - header->xmin + 1;
*height = header->ymax - header->ymin + 1;
/* Allocate enough room for the data and colourmap*/
data = malloc(*width * *height * 4);
if (!data)
{
munmap(header, file_length);
return NULL;
}
/* Decode the data */
pcx_raw_decode24(data, header->data, *width, *height);
/* Clean up */
munmap(header, file_length);
close(fd);
return data;
}
/* -------------------------------------------------------------------- */
Pixbuf*
pixbuf_new(int width, int height)
{
Pixbuf *pixb;
pixb = util_malloc0(sizeof(Pixbuf));
pixb->width = width;
pixb->height = height;
pixb->bytes_per_pixel = 4;
pixb->channels = 4;
pixb->bytes_per_line = pixb->bytes_per_pixel * pixb->width;
pixb->data = malloc(pixb->bytes_per_line * pixb->height);
memset(pixb->data, 0, pixb->bytes_per_line * pixb->height);
return pixb;
}
void
pixbuf_unref(Pixbuf *pixb)
{
pixb->refcnt--;
if (pixb->refcnt < 0)
{
free(pixb->data);
free(pixb);
}
}
void
pixbuf_ref(Pixbuf *pixb)
{
pixb->refcnt++;
}
Pixbuf*
pixbuf_new_from_file(const char *filename)
{
Pixbuf *pixb;
pixb = util_malloc0(sizeof(Pixbuf));
if (!strcasecmp(&filename[strlen(filename)-4], ".png"))
pixb->data =load_png_file(filename, &pixb->width, &pixb->height);
else if (!strcasecmp(&filename[strlen(filename)-4], ".jpg")
|| !strcasecmp(&filename[strlen(filename)-5], ".jpeg"))
pixb->data = load_jpg_file( filename, &pixb->width, &pixb->height);
else if (!strcasecmp(&filename[strlen(filename)-4], ".pcx"))
pixb->data = load_pcx_file( filename, &pixb->width, &pixb->height);
if (pixb->data == NULL)
{
free (pixb);
return NULL;
}
pixb->bytes_per_pixel = 4;
pixb->channels = 4;
pixb->bytes_per_line = pixb->bytes_per_pixel * pixb->width;
return pixb;
}
void
pixbuf_set_pixel(Pixbuf *pixb, int x, int y, PixbufPixel *p)
{
int *offset = pixb->data + ( y * pixb->width) + x;
/* ARGB_32 MSB */
// *offset = (p->r << 0) | (p->g << 8) | (p->b << 16) | (p->a << 24);
*offset = ( (p->r << 24) | (p->g << 16) | (p->b << 8) | (p->a) );
/*
printf("set %i,%i,%i,%i\n", p->r, p->g, p->b, p->a);
printf("Looks like %i %x\n", *offset, *offset);
*/
}
void
pixbuf_get_pixel(Pixbuf *pixb, int x, int y, PixbufPixel *p)
{
int *offset = pixb->data + ( y * pixb->width) + x;
/* ARGB_32 MSB */
p->r = (*offset >> 24) & 0xff;
p->g = (*offset >> 16) & 0xff;
p->b = (*offset >> 8) & 0xff;
p->a = *offset & 0xff;
}
void /* XXX could be DEFINE */
pixel_set_vals(PixbufPixel *p,
const unsigned char r,
const unsigned char g,
const unsigned char b,
const unsigned char a)
{
p->r = r; p->g = g; p->b = b; p->a = a;
}
void
pixbuf_copy(Pixbuf *src_pixb,
Pixbuf *dst_pixb,
int srcx,
int srcy,
int srcw,
int srch,
int dstx,
int dsty)
{
int j, *sp, *dp;
sp = src_pixb->data + (srcy * src_pixb->width) + srcx;
dp = dst_pixb->data + (dsty * dst_pixb->width) + dstx;
/* basic source clipping - needed by texture tiling code */
if (srcx + srcw > src_pixb->width)
srcw = src_pixb->width - srcx;
if (srcy + srch > src_pixb->height)
srch = src_pixb->height - srcy;
while (srch--)
{
j = srcw;
while (j--)
*dp++ = *sp++;
dp += (dst_pixb->width - srcw);
sp += (src_pixb->width - srcw);
}
}
void
pixbuf_fill_rect(Pixbuf *pixb,
int x,
int y,
int width,
int height,
PixbufPixel *p)
{
int i, j;
if (width < 0) width = pixb->width;
if (height < 0) height = pixb->height;
for (i = x; i<width; i++)
for (j =y; j<height; j++)
pixbuf_set_pixel(pixb, i, j, p);
}
Pixbuf *
pixbuf_scale_down(Pixbuf *pixb,
int new_width,
int new_height)
{
Pixbuf *pixb_scaled;
int *xsample, *ysample, *dest, *src, *srcy;
int i, x, y, r, g, b, a, nb_samples, xrange, yrange, rx, ry;
if ( new_width > pixb->width || new_height > pixb->height)
return NULL;
pixb_scaled = pixbuf_new(new_width, new_height);
xsample = malloc( (new_width+1) * sizeof(int));
ysample = malloc( (new_height+1) * sizeof(int));
for ( i = 0; i <= new_width; i++ )
xsample[i] = i * pixb->width / new_width;
for ( i = 0; i <= new_height; i++ )
ysample[i] = i * pixb->height / new_height * pixb->width;
dest = pixb_scaled->data;
/* scan output image */
for ( y = 0; y < new_height; y++ )
{
yrange = ( ysample[y+1] - ysample[y] ) / pixb->width;
for ( x = 0; x < new_width; x++)
{
xrange = xsample[x+1] - xsample[x];
srcy = pixb->data + ( ysample[y] + xsample[x] );
/* average R,G,B,A values on sub-rectangle of source image */
nb_samples = xrange * yrange;
if ( nb_samples > 1 )
{
r = 0; g = 0; b = 0; a = 0;
for ( ry = 0; ry < yrange; ry++ )
{
src = srcy;
for ( rx = 0; rx < xrange; rx++ )
{
/* average R,G,B,A values */
r += *src & 0xff;
g += ((*src) >> 8) & 0xff;
b += ((*src) >> 16) & 0xff;
a += ((*src) >> 24) & 0xff;
src++;
}
srcy += pixb->width;
}
*dest++ =
((unsigned char)(r/nb_samples) << 0) |
((unsigned char)(g/nb_samples) << 8) |
((unsigned char)(b/nb_samples) << 16) |
((unsigned char)(a/nb_samples) << 24);
}
else
{
*dest++ = *srcy++;
}
}
}
/* cleanup */
free( xsample );
free( ysample );
return pixb_scaled;
}
Pixbuf*
pixbuf_clone(Pixbuf *pixb)
{
Pixbuf *clone;
clone = util_malloc0(sizeof(Pixbuf));
clone->width = pixb->width;
clone->height = pixb->height;
clone->bytes_per_pixel = pixb->bytes_per_pixel;
clone->channels = pixb->channels;
clone->bytes_per_line = pixb->bytes_per_line;
clone->data = malloc(pixb->bytes_per_line * pixb->height);
memcpy(clone->data, pixb->data, pixb->bytes_per_line * pixb->height);
return clone;
}
Pixbuf*
pixbuf_convolve(Pixbuf *pixb,
int *kernel,
int kernel_size,
int kernel_divisor)
{
int padding, x, y, r, g, b, a, l, k;
PixbufPixel pixel;
Pixbuf *clone_pixb;
padding = ( kernel_size - 1 ) / 2;
clone_pixb = pixbuf_clone(pixb);
for( y = padding; y < pixb->height - padding; y++ )
{
for( x = padding; x < pixb->width - padding; x++ )
{
r = b = g = a = 0;
for( l = 0; l < kernel_size; l++ )
{
for( k = 0; k < kernel_size; k++ )
{
pixbuf_get_pixel(pixb, (x+k-padding), (y+l-padding), &pixel);
r += pixel.r * kernel[k + l * kernel_size];
g += pixel.g * kernel[k + l * kernel_size];
b += pixel.b * kernel[k + l * kernel_size];
a += pixel.a * kernel[k + l * kernel_size];
}
}
r = CLTR_CLAMP( r / kernel_divisor, 0xff);
g = CLTR_CLAMP( g / kernel_divisor, 0xff);
b = CLTR_CLAMP( b / kernel_divisor, 0xff);
a = CLTR_CLAMP( a / kernel_divisor, 0xff);
pixel_set_vals(&pixel, r, g, b, a);
pixbuf_set_pixel(clone_pixb, x, y, &pixel);
}
}
return clone_pixb;
}
Pixbuf*
pixbuf_blur(Pixbuf *pixb)
{
/*
int kernel[] = { 1, 1, 1,
1, 0, 1,
1, 1, 1 };
*/
int kernel[] = { 1, 1, 1,
1, 1, 1,
1, 1, 1 };
return pixbuf_convolve( pixb, kernel, 3, 9 );
}
Pixbuf*
pixbuf_sharpen(Pixbuf *pixb)
{
int kernel[] = {-1, -1, -1,
-1, 9, -1,
-1, -1, -1 };
return pixbuf_convolve( pixb, kernel, 3, 1 );
}
#if 0
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% C o n v o l v e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Method ConvolveImage applies a general image convolution kernel to an
% image returns the results. ConvolveImage allocates the memory necessary for
% the new Image structure and returns a pointer to the new image.
%
% The format of the ConvolveImage method is:
%
% Image *ConvolveImage(Image *image,const unsigned int order,
% const double *kernel,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o convolve_image: Method ConvolveImage returns a pointer to the image
% after it is convolved. A null image is returned if there is a memory
% shortage.
%
% o image: The address of a structure of type Image; returned from
% ReadImage.
%
% o order: The number of columns and rows in the filter kernel.
%
% o kernel: An array of double representing the convolution kernel.
%
% o exception: return any errors or warnings in this structure.
%
%
*/
MagickExport Image *ConvolveImage(Image *image,
const unsigned int order,
const double *kernel,
ExceptionInfo *exception)
{
#define ConvolveImageText " Convolving image... "
#define Cx(x) \
(x) < 0 ? (x)+image->columns : (x) >= image->columns ? (x)-image->columns : x
#define Cy(y) \
(y) < 0 ? (y)+image->rows : (y) >= image->rows ? (y)-image->rows : y
double
blue,
green,
normalize,
opacity,
red;
Image
*convolve_image;
int
i,
width,
y;
PixelPacket
*p,
pixel;
register const double
*k;
register int
u,
v,
x;
register PixelPacket
*q,
*s;
/*
Initialize convolved image attributes.
*/
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
width=order;
if ((width % 2) == 0)
ThrowImageException(OptionWarning,"Unable to convolve image",
"kernel width must be an odd number");
if ((image->columns < width) || (image->rows < width))
ThrowImageException(OptionWarning,"Unable to convolve image",
"image smaller than kernel width");
convolve_image=CloneImage(image,image->columns,image->rows,False,exception);
if (convolve_image == (Image *) NULL)
return((Image *) NULL);
convolve_image->storage_class=DirectClass;
/*
Convolve image.
*/
normalize=0.0;
for (i=0; i < (width*width); i++)
normalize+=kernel[i];
for (y=0; y < (int) convolve_image->rows; y++)
{
p=(PixelPacket *) NULL;
q=SetImagePixels(convolve_image,0,y,convolve_image->columns,1);
if (q == (PixelPacket *) NULL)
break;
for (x=0; x < (int) convolve_image->columns; x++)
{
red=0.0;
green=0.0;
blue=0.0;
opacity=0.0;
k=kernel;
if ((x < (width/2)) || (x >= (int) (image->columns-width/2)) ||
(y < (width/2)) || (y >= (int) (image->rows-width/2)))
{
for (v=(-width/2); v <= (width/2); v++)
{
for (u=(-width/2); u <= (width/2); u++)
{
pixel=GetOnePixel(image,Cx(x+u),Cy(y+v));
red+=(*k)*pixel.red;
green+=(*k)*pixel.green;
blue+=(*k)*pixel.blue;
opacity+=(*k)*pixel.opacity;
k++;
}
}
}
else
{
if (p == (PixelPacket *) NULL)
{
p=GetImagePixels(image,0,y-width/2,image->columns,width);
if (p == (PixelPacket *) NULL)
break;
}
s=p+x;
for (v=(-width/2); v <= (width/2); v++)
{
for (u=(-width/2); u <= (width/2); u++)
{
red+=(*k)*s[u].red;
green+=(*k)*s[u].green;
blue+=(*k)*s[u].blue;
opacity+=(*k)*s[u].opacity;
k++;
}
s+=image->columns;
}
}
if ((normalize != 0.0) && (normalize != 1.0))
{
red/=normalize;
green/=normalize;
blue/=normalize;
opacity/=normalize;
}
q->red=(Quantum) ((red < 0) ? 0 : (red > MaxRGB) ? MaxRGB : red+0.5);
q->green=(Quantum)
((green < 0) ? 0 : (green > MaxRGB) ? MaxRGB : green+0.5);
q->blue=(Quantum) ((blue < 0) ? 0 : (blue > MaxRGB) ? MaxRGB : blue+0.5);
q->opacity=(Quantum)
((opacity < 0) ? 0 : (opacity > MaxRGB) ? MaxRGB : opacity+0.5);
q++;
}
if (!SyncImagePixels(convolve_image))
break;
if (QuantumTick(y,convolve_image->rows))
MagickMonitor(ConvolveImageText,y,convolve_image->rows);
}
return(convolve_image);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% G a u s s i a n B l u r I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Method GaussianBlurImage creates a new image that is a copy of an existing
% one with the pixels blur. It allocates the memory necessary for the
% new Image structure and returns a pointer to the new image.
%
% The format of the BlurImage method is:
%
% Image *GaussianBlurImage(Image *image,const double radius,
% const double sigma,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o blur_image: Method GaussianBlurImage returns a pointer to the image
% after it is blur. A null image is returned if there is a memory
% shortage.
%
% o radius: the radius of the Gaussian, in pixels, not counting the center
% pixel.
%
% o sigma: the standard deviation of the Gaussian, in pixels.
%
% o exception: return any errors or warnings in this structure.
%
%
*/
MagickExport Image *GaussianBlurImage(Image *image,const double radius,
const double sigma,ExceptionInfo *exception)
{
double
*kernel;
Image
*blur_image;
int
width;
register int
i,
u,
v;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
width=GetOptimalKernelWidth2D(radius,sigma);
if ((image->columns < width) || (image->rows < width))
ThrowImageException(OptionWarning,"Unable to Gaussian blur image",
"image is smaller than radius");
kernel=(double *) AcquireMemory(width*width*sizeof(double));
if (kernel == (double *) NULL)
ThrowImageException(ResourceLimitWarning,"Unable to Gaussian blur image",
"Memory allocation failed");
i=0;
for (v=(-width/2); v <= (width/2); v++)
{
for (u=(-width/2); u <= (width/2); u++)
{
kernel[i]=exp((double) -(u*u+v*v)/(sigma*sigma));
i++;
}
}
blur_image=ConvolveImage(image,width,kernel,exception);
LiberateMemory((void **) &kernel);
return(blur_image);
}
/* GPE-gallery convolve code */
static void
image_convolve( GdkPixbuf *pixbuf,
int *mask,
int mask_size,
int mask_divisor ) {
int x, y, k, l, b, rowstride, width, height, channels, padding, new_value;
int* temp_pixel;
guchar *temp_image, *image;
rowstride = gdk_pixbuf_get_rowstride( GDK_PIXBUF( pixbuf ) );
channels = gdk_pixbuf_get_n_channels( GDK_PIXBUF( pixbuf ) );
width = gdk_pixbuf_get_width( GDK_PIXBUF( pixbuf ) );
height = gdk_pixbuf_get_height( GDK_PIXBUF( pixbuf ) );
// fprintf( stderr, "Rowstride: %d, width: %d, height: %d, channels: %d\n", rowstride, width, height, channels );
padding = ( mask_size - 1 ) / 2;
image = gdk_pixbuf_get_pixels( GDK_PIXBUF( pixbuf ) );
temp_image = (guchar*) malloc( width * height * channels * sizeof( guchar ) );
memcpy( temp_image, image, width * height * channels * sizeof( guchar ) );
temp_pixel =(int*) malloc( channels * sizeof( int ) );
for( y = padding; y < height - padding; y++ ) {
for( x = padding; x < width - padding; x++ ) {
for( b = 0; b < channels; b++ )
temp_pixel[b] = 0;
for( l = 0; l < mask_size; l++ ) {
for( k = 0; k < mask_size; k++ ) {
for( b = 0; b < channels; b++ )
temp_pixel[b] += temp_image[ ( y + l - padding ) * rowstride
+ ( x + k - padding ) * channels + b ] * mask[ k + l *
mask_size ];
}
}
for( b = 0; b < channels; b++ ) {
new_value = temp_pixel[b] / mask_divisor;
image[ y * rowstride + x * channels + b ] = ( new_value > 255 ? 255
: new_value < 0 ? 0 : new_value );
}
}
}
free( temp_image );
free( temp_pixel );
}
void image_tools_blur( GdkPixbuf* pixbuf ) {
int mask[] = { 1, 1, 1,
1, 1, 1,
1, 1, 1 };
image_convolve( pixbuf, mask, 3, 9 );
}
void image_tools_sharpen( GdkPixbuf* pixbuf ) {
int mask[] = {-1, -1, -1,
-1, 9, -1,
-1, -1, -1 };
image_convolve( pixbuf, mask, 3, 1 );
}
#endif