void Image::flip()
{
// create a temp swap space
size_t bpChannel = getBytesPerChannel();
unsigned char *buf = new unsigned char[bpChannel];
for (size_t i=0; i<m_width; ++i)
{
for (size_t j=0; j<m_height/2; ++j)
{
for (size_t k=0; k<m_nChannels; ++k)
{
// swap pixels
memcpy(buf, &m_data[m_bytesPerPixel*(j*m_height + i) + bpChannel*k], bpChannel);
memcpy( &m_data[m_bytesPerPixel*(j*m_height + i) + bpChannel*k],
&m_data[m_bytesPerPixel*((m_height-1-j)*m_height + i) + bpChannel*k],
bpChannel);
memcpy(&m_data[m_bytesPerPixel*((m_height-1-j)*m_height + i) + bpChannel*k], buf, bpChannel);
}
}
}
}
bool ImagePNG::save(std::string filename, int compression_level)
{
FILE *file;
#ifndef NDEBUG
std::cout << "Writing PNG file " << filename << std::endl;
#endif
/* make sure the file is there and open it read-only (binary) */
if ((file = fopen(filename.c_str(), "wb")) == NULL)
{
std::cerr << "File write access failed : " << filename << std::endl;
return false;
}
png_structp PNG_writer = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (PNG_writer == NULL)
{
std::cerr << "png_create_write_struct failed for file "<< filename << std::endl;
fclose(file);
return false;
}
png_infop PNG_info = png_create_info_struct(PNG_writer);
if (PNG_info == NULL)
{
std::cerr << "png_create_info_struct failed for file " << filename << std::endl;
png_destroy_write_struct(&PNG_writer, NULL);
fclose(file);
return false;
}
if (setjmp(png_jmpbuf(PNG_writer)))
{
std::cerr << "Writing failed for PNG file " << filename << std::endl;
png_destroy_write_struct(&PNG_writer, &PNG_info);
fclose(file);
return false;
}
//png_init_io(PNG_writer, file);
png_set_write_fn(PNG_writer, file, png_my_write_data, png_default_flush);
png_uint_32 width, height;
png_uint_32 bit_depth, channels, color_type;
width = getWidth();
height = getHeight();
bit_depth = getBytesPerChannel() * 8;
channels = getChannelCount();
if (channels == 1)
color_type = PNG_COLOR_TYPE_GRAY;
else if (channels == 2)
color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
else if (channels == 3)
color_type = PNG_COLOR_TYPE_RGB;
else
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
if (bit_depth != 8)
{
std::cerr << "Unsupported bitdepth "<< bit_depth <<" to write to PNG file "<<filename<<std::endl;
png_destroy_write_struct(&PNG_writer, &PNG_info);
fclose(file);
return false;
}
#ifndef NDEBUG
std::cout << "PNG image "<<filename<<": "<<width<<"x"<<height<<"x"<<bit_depth*channels<<std::endl;
#endif
png_set_IHDR(PNG_writer, PNG_info, width, height,
bit_depth, color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
/* set the zlib compression level */
if (compression_level!=-1)
{
if (compression_level>=0 && compression_level<=9)
png_set_compression_level(PNG_writer, compression_level);
else
std::cerr << "ERROR: compression level must be a value between 0 and 9" << std::endl;
}
png_byte** PNG_rows = (png_byte**)malloc(height * sizeof(png_byte*));
unsigned char *data = getPixels();
unsigned lineSize = getLineSize(0);
for (png_uint_32 row = 0; row < height; ++row)
PNG_rows[height - 1 - row] = data+row*lineSize;
png_set_rows(PNG_writer, PNG_info, PNG_rows);
png_write_png(PNG_writer, PNG_info, PNG_TRANSFORM_IDENTITY, NULL);
free(PNG_rows);
png_destroy_write_struct(&PNG_writer, &PNG_info);
fclose(file);
return true;
}
int ofPixels_<PixelType>::getBitsPerChannel() const{
return getBytesPerChannel() * 8;
}
int ofPixels_<PixelType>::getBytesPerPixel() const{
return getBytesPerChannel() * channels;
}
