static inline void
copy_pixels_ (const ImageBuf &buf, int xbegin, int xend,
int ybegin, int yend, D *r)
{
int w = (xend-xbegin);
for (ImageBuf::ConstIterator<S,D> p (buf, xbegin, xend, ybegin, yend);
p.valid(); ++p) {
imagesize_t offset = ((p.y()-ybegin)*w + (p.x()-xbegin)) * buf.nchannels();
for (int c = 0; c < buf.nchannels(); ++c)
r[offset+c] = p[c];
}
}
static inline void
getpixel_ (const ImageBuf &buf, int x, int y, int z, float *result, int chans)
{
ImageBuf::ConstIterator<T> pixel (buf, x, y, z);
if (pixel.valid()) {
for (int i = 0; i < chans; ++i)
result[i] = pixel[i];
} else {
for (int i = 0; i < chans; ++i)
result[i] = 0.0f;
}
}
// DEPRECATED version
bool
ImageBufAlgo::add (ImageBuf &dst, const ImageBuf &A, const ImageBuf &B,
int options)
{
// Sanity checks
// dst must be distinct from A and B
if ((const void *)&A == (const void *)&dst ||
(const void *)&B == (const void *)&dst) {
dst.error ("destination image must be distinct from source");
return false;
}
// all three images must have the same number of channels
if (A.spec().nchannels != B.spec().nchannels) {
dst.error ("channel number mismatch: %d vs. %d",
A.spec().nchannels, B.spec().nchannels);
return false;
}
// If dst has not already been allocated, set it to the right size,
// make it unconditinally float
if (! dst.pixels_valid()) {
ImageSpec dstspec = A.spec();
dstspec.set_format (TypeDesc::TypeFloat);
dst.alloc (dstspec);
}
// Clear dst pixels if instructed to do so
if (options & ADD_CLEAR_DST) {
zero (dst);
}
ASSERT (A.spec().format == TypeDesc::FLOAT &&
B.spec().format == TypeDesc::FLOAT &&
dst.spec().format == TypeDesc::FLOAT);
ImageBuf::ConstIterator<float,float> a (A);
ImageBuf::ConstIterator<float,float> b (B);
ImageBuf::Iterator<float> d (dst);
int nchannels = A.nchannels();
// Loop over all pixels in A
for ( ; a.valid(); ++a) {
// Point the iterators for B and dst to the corresponding pixel
if (options & ADD_RETAIN_WINDOWS) {
b.pos (a.x(), a.y());
} else {
// ADD_ALIGN_WINDOWS: make B line up with A
b.pos (a.x()-A.xbegin()+B.xbegin(), a.y()-A.ybegin()+B.ybegin());
}
d.pos (a.x(), b.y());
if (! b.valid() || ! d.valid())
continue; // Skip pixels that don't align
// Add the pixel
for (int c = 0; c < nchannels; ++c)
d[c] = a[c] + b[c];
}
return true;
}
void
IvImage::pixel_transform(bool srgb_to_linear, int color_mode, int select_channel)
{
/// This table obeys the following function:
///
/// unsigned char srgb2linear(unsigned char x)
/// {
/// float x_f = x/255.0;
/// float x_l = 0.0;
/// if (x_f <= 0.04045)
/// x_l = x_f/12.92;
/// else
/// x_l = powf((x_f+0.055)/1.055,2.4);
/// return (unsigned char)(x_l * 255 + 0.5)
/// }
///
/// It's used to transform from sRGB color space to linear color space.
static const unsigned char srgb_to_linear_lut[256] = {
0, 0, 0, 0, 0, 0, 0, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 2, 2, 2, 2, 2, 2,
2, 2, 3, 3, 3, 3, 3, 3,
4, 4, 4, 4, 4, 5, 5, 5,
5, 6, 6, 6, 6, 7, 7, 7,
8, 8, 8, 8, 9, 9, 9, 10,
10, 10, 11, 11, 12, 12, 12, 13,
13, 13, 14, 14, 15, 15, 16, 16,
17, 17, 17, 18, 18, 19, 19, 20,
20, 21, 22, 22, 23, 23, 24, 24,
25, 25, 26, 27, 27, 28, 29, 29,
30, 30, 31, 32, 32, 33, 34, 35,
35, 36, 37, 37, 38, 39, 40, 41,
41, 42, 43, 44, 45, 45, 46, 47,
48, 49, 50, 51, 51, 52, 53, 54,
55, 56, 57, 58, 59, 60, 61, 62,
63, 64, 65, 66, 67, 68, 69, 70,
71, 72, 73, 74, 76, 77, 78, 79,
80, 81, 82, 84, 85, 86, 87, 88,
90, 91, 92, 93, 95, 96, 97, 99,
100, 101, 103, 104, 105, 107, 108, 109,
111, 112, 114, 115, 116, 118, 119, 121,
122, 124, 125, 127, 128, 130, 131, 133,
134, 136, 138, 139, 141, 142, 144, 146,
147, 149, 151, 152, 154, 156, 157, 159,
161, 163, 164, 166, 168, 170, 171, 173,
175, 177, 179, 181, 183, 184, 186, 188,
190, 192, 194, 196, 198, 200, 202, 204,
206, 208, 210, 212, 214, 216, 218, 220,
222, 224, 226, 229, 231, 233, 235, 237,
239, 242, 244, 246, 248, 250, 253, 255
};
unsigned char correction_table[256];
int total_channels = spec().nchannels;
int color_channels = spec().nchannels;
int max_channels = m_corrected_image.nchannels();
// FIXME: Now with the iterator and data proxy in place, it should be
// trivial to apply the transformations to any kind of data, not just
// UINT8.
if (spec().format != TypeDesc::UINT8 || ! m_corrected_image.localpixels()) {
return;
}
if (color_channels > 3) {
color_channels = 3;
} else if (color_channels == 2) {
color_channels = 1;
}
// This image is Luminance or Luminance + Alpha, and we are asked to show
// luminance.
if (color_channels == 1 && color_mode == 3) {
color_mode = 0; // Just copy as usual.
}
// Happy path:
if (! srgb_to_linear && color_mode <= 1 && m_gamma == 1.0 && m_exposure == 0.0) {
ImageBuf::ConstIterator<unsigned char, unsigned char> src (*this);
ImageBuf::Iterator<unsigned char, unsigned char> dst (m_corrected_image);
for ( ; src.valid (); ++src) {
dst.pos (src.x(), src.y());
for (int i = 0; i < max_channels; i++)
dst[i] = src[i];
}
return;
}
// fill the correction_table
if (gamma() == 1.0 && exposure() == 0.0) {
for (int pixelvalue = 0; pixelvalue < 256; ++pixelvalue) {
correction_table[pixelvalue] = pixelvalue;
}
} else {
float inv_gamma = 1.0/gamma();
float gain = powf (2.0f, exposure());
for (int pixelvalue = 0; pixelvalue < 256; ++pixelvalue) {
float pv_f = converter (pixelvalue);
pv_f = clamp (calc_exposure (pv_f, gain, inv_gamma),
0.0f, 1.0f);
correction_table[pixelvalue] = (unsigned char) (pv_f*255 + 0.5);
}
}
ImageBuf::ConstIterator<unsigned char, unsigned char> src (*this);
ImageBuf::Iterator<unsigned char, unsigned char> dst (m_corrected_image);
for ( ; src.valid(); ++src) {
dst.pos (src.x(), src.y());
if (color_mode == 0 || color_mode == 1) {
// RGBA, RGB modes.
int ch = 0;
for (ch = 0; ch < color_channels; ch++) {
if (srgb_to_linear)
dst[ch] = correction_table[srgb_to_linear_lut[src[ch]]];
else
dst[ch] = correction_table[src[ch]];
}
for (; ch < max_channels; ch++) {
dst[ch] = src[ch];
}
} else if (color_mode == 3) {
// Convert RGB to luminance, (Rec. 709 luma coefficients).
float luminance;
if (srgb_to_linear) {
luminance = converter (srgb_to_linear_lut[src[0]])*0.2126f +
converter (srgb_to_linear_lut[src[1]])*0.7152f +
converter (srgb_to_linear_lut[src[2]])*0.0722f;
} else {
luminance = converter (src[0])*0.2126f +
converter (src[1])*0.7152f +
converter (src[2])*0.0722f;
}
unsigned char val = (unsigned char) (clamp (luminance, 0.0f, 1.0f) * 255.0 + 0.5);
val = correction_table[val];
dst[0] = val;
dst[1] = val;
dst[2] = val;
// Handle the rest of the channels
for (int ch = 3; ch < total_channels; ++ch) {
dst[ch] = src[ch];
}
} else { // Single channel, heatmap.
unsigned char v = 0;
if (select_channel < color_channels) {
if (srgb_to_linear)
v = correction_table[srgb_to_linear_lut[src[select_channel]]];
else
v = correction_table[src[select_channel]];
} else if (select_channel < total_channels) {
v = src[select_channel];
}
int ch = 0;
for (; ch < color_channels; ++ch) {
dst[ch] = v;
}
for (; ch < max_channels; ++ch) {
dst[ch] = src[ch];
}
}
}
}