#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <sys/types.h>
#include <jpeglib.h>
#include <setjmp.h>
int main(int argc, char* argv[])
{
/******************************************************************************************************/
/* Begin Variable Initialization */
/******************************************************************************************************/
FILE *ifp;
u_int16_t *Amplitude,i;
typedef struct eWavHead
{
u_int64_t Channels; /* number of channels stored in file */
u_int64_t WFD_Offset; /* Offset in bytes from beginning of file to first eWav File Directory */
} eWavHead; /* 16 bytes */
typedef struct ChannelHeader
{
float ResX; /* Image resolution in dots/cm */
float RexY; /* Image resolution in dots/cm */
double Scale_mm_sec;
double Scale_mv_cm;
u_int32_t Samples;
} ChannelHeader;
eWavHead FileHeader;
ChannelHeader ch;
u_int16_t max,min;
JSAMPLE * image_buffer; /* Points to large array of R,G,B-order data */
int image_height; /* Number of rows in image */
int image_width; /* Number of columns in image */
int image_float;
/* This struct contains the JPEG compression parameters and pointers to
* working space (which is allocated as needed by the JPEG library).
* It is possible to have several such structures, representing multiple
* compression/decompression processes, in existence at once. We refer
* to any one struct (and its associated working data) as a "JPEG object".
*/
struct jpeg_compress_struct cinfo;
/* This struct represents a JPEG error handler. It is declared separately
* because applications often want to supply a specialized error handler
* (see the second half of this file for an example). But here we just
* take the easy way out and use the standard error handler, which will
* print a message on stderr and call exit() if compression fails.
* Note that this struct must live as long as the main JPEG parameter
* struct, to avoid dangling-pointer problems.
*/
struct jpeg_error_mgr jerr;
/* More stuff */
FILE * outfile; /* target file */
JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
int row_stride; /* physical row width in image buffer */
int j,x,y;
float xpixline,ypixline,xstep,ystep;
int bottom, top, last;
/******************************************************************************************************/
/* End Variable Initialization */
/******************************************************************************************************/
ifp = fopen(argv[1], "rb");
fread(&FileHeader,sizeof(eWavHead),1,ifp);
fread(&ch,sizeof(ChannelHeader),1,ifp);
printf("Channels:%d, Offset:%d\n",(int)FileHeader.Channels,(int)FileHeader.WFD_Offset);
printf("X resolution: %f, Y resolution: %f, cm/sec: %f, Millivolts/cm: %f, Samples:%d\n",
ch.ResX,ch.RexY,ch.Scale_mm_sec/10,ch.Scale_mv_cm,(int)ch.Samples);
image_height=1.5*(max-min);
if (4096>ch.Samples)
image_width=ch.Samples;
else
image_width=4096;
image_float=0.25*(max-min);
Amplitude=(u_int16_t *)calloc(image_width,sizeof(u_int16_t));
fread(Amplitude,sizeof(u_int16_t),image_width,ifp);
fclose(ifp);
max=min=Amplitude[0];
for(i=0;i<image_width;i++)
{
// printf("X=%d, Y=%d\n",i,Amplitude[i]);
if (Amplitude[i]>max)
max=Amplitude[i];
if (Amplitude[i]<min)
min=Amplitude[i];
}
printf("Max amp=%d, Min amp=%d\n",max,min);
printf("Pixels/sec:%f, Pixels/mVolt:%f\n",ch.ResX*ch.Scale_mm_sec/10,ch.RexY*ch.Scale_mv_cm);
xpixline=(ch.ResX*ch.Scale_mm_sec/10)/5;
ypixline=(ch.RexY*ch.Scale_mv_cm);
printf ("xpixline=%f, ypixline=%f\n",xpixline,ypixline);
/*===============================================*/
xstep=image_width/xpixline;
ystep=image_height/ypixline;
printf("xstep=%f, ystep=%f\n",xstep,ystep);
/* Generate image space */
image_buffer=calloc(image_height*image_width,sizeof(u_int8_t));
/* Clear image */
for(x=image_width-1;x>=0;x--)
for(y=image_height-1;y>=0;y--)
image_buffer[y*image_width+x]=255;
/* Draw vertical grid lines */
for (x=0;x<=(int)(xstep);x++)
for (y=0;y<image_height;y++)
{
image_buffer[y*image_width+((int)floor(x*xpixline))]=200;
image_buffer[y*image_width+((int)floor(x*xpixline))+1]=200;
}
/* Draw horizontal grid lines */
for (y=0;y<=(int)(ystep);y++)
for (x=0;x<image_width;x++)
{
image_buffer[(int)floor(y*ypixline)*image_width+x]=200;
image_buffer[((int)floor(y*ypixline)+1)*image_width+x]=200;
}
/* Draw Signal */
last=Amplitude[0];
for (x=1;x<image_width-1;x++)
{
bottom=-2;
top=2;
/* This makes the line at least 5 pixels wide. */
/* if the datapoints are seperated by more than 2 pixels, the line is made */
/* wider by the corresponding number of pixels. */
if (last-Amplitude[x]<bottom)
bottom=last-Amplitude[x]-2;
if (last-Amplitude[x]>top)
top=last-Amplitude[x]+2;
// printf("Last=%d, current=%d, Bottom=%d, Top=%d\n",last,Amplitude[x],bottom,top);
last=Amplitude[x];
for (y=bottom;y<=top;y++)
for (j=-1;j<=1;j++)
image_buffer[(image_height-(Amplitude[x]-min+image_float+y))*image_width+x+j]=0;
}
/*===============================================*/
/* Step 1: allocate and initialize JPEG compression object */
/* We have to set up the error handler first, in case the initialization
* step fails. (Unlikely, but it could happen if you are out of memory.)
* This routine fills in the contents of struct jerr, and returns jerr's
* address which we place into the link field in cinfo.
*/
cinfo.err = jpeg_std_error(&jerr);
/* Now we can initialize the JPEG compression object. */
jpeg_create_compress(&cinfo);
/* Step 2: specify data destination (eg, a file) */
/* Note: steps 2 and 3 can be done in either order. */
/* Here we use the library-supplied code to send compressed data to a
* stdio stream. You can also write your own code to do something else.
* VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
* requires it in order to write binary files.
*/
if ((outfile = fopen(argv[2], "wb")) == NULL) {
fprintf(stderr, "can't open %s\n", argv[2]);
exit(1);
}
jpeg_stdio_dest(&cinfo, outfile);
/* Step 3: set parameters for compression */
/* First we supply a description of the input image.
* Four fields of the cinfo struct must be filled in:
*/
cinfo.image_width = image_width; /* image width and height, in pixels */
cinfo.image_height = image_height;
cinfo.input_components = 1; /* # of color components per pixel */
cinfo.in_color_space = JCS_GRAYSCALE; /* colorspace of input image */
/* Now use the library's routine to set default compression parameters.
* (You must set at least cinfo.in_color_space before calling this,
* since the defaults depend on the source color space.)
*/
jpeg_set_defaults(&cinfo);
/* Now you can set any non-default parameters you wish to.
* Here we just illustrate the use of quality (quantization table) scaling:
*/
jpeg_set_quality(&cinfo, atoi(argv[3]), TRUE /* limit to baseline-JPEG values */);
/* Step 4: Start compressor */
/* TRUE ensures that we will write a complete interchange-JPEG file.
* Pass TRUE unless you are very sure of what you're doing.
*/
jpeg_start_compress(&cinfo, TRUE);
/* Step 5: while (scan lines remain to be written) */
/* jpeg_write_scanlines(...); */
/* Here we use the library's state variable cinfo.next_scanline as the
* loop counter, so that we don't have to keep track ourselves.
* To keep things simple, we pass one scanline per call; you can pass
* more if you wish, though.
*/
row_stride = image_width * 1; /* JSAMPLEs per row in image_buffer */
while (cinfo.next_scanline < cinfo.image_height) {
/* jpeg_write_scanlines expects an array of pointers to scanlines.
* Here the array is only one element long, but you could pass
* more than one scanline at a time if that's more convenient.
*/
row_pointer[0] = & image_buffer[cinfo.next_scanline * row_stride];
(void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
/* Step 6: Finish compression */
jpeg_finish_compress(&cinfo);
/* After finish_compress, we can close the output file. */
fclose(outfile);
/* Step 7: release JPEG compression object */
/* This is an important step since it will release a good deal of memory. */
jpeg_destroy_compress(&cinfo);
/* And we're done! */
exit(0);
}