C++ ImageBuf::deep_value方法代码示例

static bool
flatten_ (ImageBuf &dst, const ImageBuf &src, 
          ROI roi, int nthreads)
{
    if (nthreads != 1 && roi.npixels() >= 1000) {
        // Possible multiple thread case -- recurse via parallel_image
        ImageBufAlgo::parallel_image (
            boost::bind(flatten_<DSTTYPE>, boost::ref(dst), boost::cref(src),
                        _1 /*roi*/, 1 /*nthreads*/),
            roi, nthreads);
        return true;
    }

    const ImageSpec &srcspec (src.spec());
    int nc = srcspec.nchannels;

    int alpha_channel, RA_channel, GA_channel, BA_channel;
    int R_channel, G_channel, B_channel;
    int Z_channel, Zback_channel;
    if (! find_deep_channels (srcspec, alpha_channel,
                              RA_channel, GA_channel, BA_channel,
                              R_channel, G_channel, B_channel,
                              Z_channel, Zback_channel)) {
        dst.error ("No alpha channel could be identified");
        return false;
    }
    ASSERT (alpha_channel >= 0 ||
            (RA_channel >= 0 && GA_channel >= 0 && BA_channel >= 0));
    float *val = ALLOCA (float, nc);
    float &RAval (RA_channel >= 0 ? val[RA_channel] : val[alpha_channel]);
    float &GAval (GA_channel >= 0 ? val[GA_channel] : val[alpha_channel]);
    float &BAval (BA_channel >= 0 ? val[BA_channel] : val[alpha_channel]);

    for (ImageBuf::Iterator<DSTTYPE> r (dst, roi);  !r.done();  ++r) {
        int x = r.x(), y = r.y(), z = r.z();
        int samps = src.deep_samples (x, y, z);
        // Clear accumulated values for this pixel (0 for colors, big for Z)
        memset (val, 0, nc*sizeof(float));
        if (Z_channel >= 0 && samps == 0)
            val[Z_channel] = 1.0e30;
        if (Zback_channel >= 0 && samps == 0)
            val[Zback_channel] = 1.0e30;
        for (int s = 0;  s < samps;  ++s) {
            float RA = RAval, GA = GAval, BA = BAval;  // make copies
            float alpha = (RA + GA + BA) / 3.0f;
            if (alpha >= 1.0f)
                break;
            for (int c = 0;  c < nc;  ++c) {
                float v = src.deep_value (x, y, z, c, s);
                if (c == Z_channel || c == Zback_channel)
                    val[c] *= alpha;  // because Z are not premultiplied
                float a;
                if (c == R_channel)
                    a = RA;
                else if (c == G_channel)
                    a = GA;
                else if (c == B_channel)
                    a = BA;
                else
                    a = alpha;
                val[c] += (1.0f - a) * v;
            }
        }

        for (int c = roi.chbegin;  c < roi.chend;  ++c)
            r[c] = val[c];
    }

    return true;
}

//.........这里部分代码省略.........
        size_t sampoffset = 0;
        int nchannels = dd->channels();
        int depthchannel = -1;
        long long nonfinites = 0;
        for (int c = 0; c < nchannels; ++c)
            if (Strutil::iequals (originalspec.channelnames[c], "Z"))
                depthchannel = c;
        int xend = originalspec.x + originalspec.width;
        int yend = originalspec.y + originalspec.height;
        int zend = originalspec.z + originalspec.depth;
        size_t p = 0;
        std::vector<size_t> nsamples_histogram;
        for (int z = originalspec.z; z < zend; ++z) {
            for (int y = originalspec.y; y < yend; ++y) {
                for (int x = originalspec.x; x < xend; ++x, ++p) {
                    size_t samples = input.deep_samples (x, y, z);
                    totalsamples += samples;
                    if (samples == maxsamples)
                        ++maxsamples_npixels;
                    if (samples > maxsamples) {
                        maxsamples = samples;
                        maxsamples_pixel.setValue (x, y, z);
                        maxsamples_npixels = 1;
                    }
                    if (samples < minsamples)
                        minsamples = samples;
                    if (samples == 0)
                        ++emptypixels;
                    if (samples >= nsamples_histogram.size())
                        nsamples_histogram.resize (samples+1, 0);
                    nsamples_histogram[samples] += 1;
                    for (unsigned int s = 0;  s < samples;  ++s) {
                        for (int c = 0;  c < nchannels; ++c) {
                            float d = input.deep_value (x, y, z, c, s);
                            if (! isfinite(d)) {
                                if (nonfinites++ == 0) {
                                    nonfinite_pixel.setValue (x, y, z);
                                    nonfinite_pixel_samp = s;
                                    nonfinite_pixel_chan = c;
                                }
                            }
                            if (depthchannel == c) {
                                if (d < mindepth) {
                                    mindepth = d;
                                    mindepth_pixel.setValue (x, y, z);
                                }
                                if (d > maxdepth) {
                                    maxdepth = d;
                                    maxdepth_pixel.setValue (x, y, z);
                                }
                            }
                        }
                    }
                    sampoffset += samples;
                }
            }
        }
        printf ("%sMin deep samples in any pixel : %llu\n", indent, (unsigned long long)minsamples);
        printf ("%sMax deep samples in any pixel : %llu\n", indent, (unsigned long long)maxsamples);
        printf ("%s%llu pixel%s had the max of %llu samples, including (x=%d, y=%d)\n",
                indent, (unsigned long long)maxsamples_npixels,
                maxsamples_npixels > 1 ? "s" : "",
                (unsigned long long)maxsamples,
                maxsamples_pixel.x, maxsamples_pixel.y);
        printf ("%sAverage deep samples per pixel: %.2f\n", indent, double(totalsamples)/double(npixels));
        printf ("%sTotal deep samples in all pixels: %llu\n", indent, (unsigned long long)totalsamples);