| public jpeg_read_header ( bool require_image ) : ReadResult | ||
| require_image | bool | Read a description of Return Value. |
| return | ReadResult | |
public ReadResult jpeg_read_header(bool require_image)
{
if (m_global_state != JpegState.DSTATE_START && m_global_state != JpegState.DSTATE_INHEADER)
ERREXIT(J_MESSAGE_CODE.JERR_BAD_STATE, (int)m_global_state);
ReadResult retcode = jpeg_consume_input();
switch (retcode)
{
case ReadResult.JPEG_REACHED_SOS:
return ReadResult.JPEG_HEADER_OK;
case ReadResult.JPEG_REACHED_EOI:
if (require_image) /* Complain if application wanted an image */
ERREXIT(J_MESSAGE_CODE.JERR_NO_IMAGE);
/* Reset to start state; it would be safer to require the application to
* call jpeg_abort, but we can't change it now for compatibility reasons.
* A side effect is to free any temporary memory (there shouldn't be any).
*/
jpeg_abort(); /* sets state = DSTATE_START */
return ReadResult.JPEG_HEADER_TABLES_ONLY;
case ReadResult.JPEG_SUSPENDED:
/* no work */
break;
}
return ReadResult.JPEG_SUSPENDED;
}
static int[][] getDct(string filename)
{
jpeg_decompress_struct cinfo = new jpeg_decompress_struct();
FileStream objFileStreamHeaderImage = new FileStream(filename, FileMode.Open, FileAccess.Read);
cinfo.jpeg_stdio_src(objFileStreamHeaderImage);
cinfo.jpeg_read_header(true);
var coeffs = cinfo.jpeg_read_coefficients();
const int size = 64;
int height = cinfo.Image_height / size;
int width = cinfo.Image_width / size;
int[][] result = new int[height * width][];
var dct = coeffs[0].Access(0, height);
for (int i = 0; i < height * width; i++)
{
result[i] = new int[size];
}
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
for (int k = 0; k < 64; k++)
{
result[i * width + j][k] = dct[i][j][k];
}
}
}
return result;
}
