darknet/src/image.c

#include "image.h"
#include "utils.h"
#include <stdio.h>
#include <math.h>

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h"

int windows = 0;

float colors[6][3] = { {1,0,1}, {0,0,1},{0,1,1},{0,1,0},{1,1,0},{1,0,0} };

float get_color(int c, int x, int max)
{
    float ratio = ((float)x/max)*5;
    int i = floor(ratio);
    int j = ceil(ratio);
    ratio -= i;
    float r = (1-ratio) * colors[i][c] + ratio*colors[j][c];
    //printf("%f\n", r);
    return r;
}

void draw_box(image a, int x1, int y1, int x2, int y2, float r, float g, float b)
{
    //normalize_image(a);
    int i;
    if(x1 < 0) x1 = 0;
    if(x1 >= a.w) x1 = a.w-1;
    if(x2 < 0) x2 = 0;
    if(x2 >= a.w) x2 = a.w-1;

    if(y1 < 0) y1 = 0;
    if(y1 >= a.h) y1 = a.h-1;
    if(y2 < 0) y2 = 0;
    if(y2 >= a.h) y2 = a.h-1;

    for(i = x1; i < x2; ++i){
        a.data[i + y1*a.w + 0*a.w*a.h] = b;
        a.data[i + y2*a.w + 0*a.w*a.h] = b;

        a.data[i + y1*a.w + 1*a.w*a.h] = g;
        a.data[i + y2*a.w + 1*a.w*a.h] = g;

        a.data[i + y1*a.w + 2*a.w*a.h] = r;
        a.data[i + y2*a.w + 2*a.w*a.h] = r;
    }
    for(i = y1; i < y2; ++i){
        a.data[x1 + i*a.w + 0*a.w*a.h] = b;
        a.data[x2 + i*a.w + 0*a.w*a.h] = b;

        a.data[x1 + i*a.w + 1*a.w*a.h] = g;
        a.data[x2 + i*a.w + 1*a.w*a.h] = g;

        a.data[x1 + i*a.w + 2*a.w*a.h] = r;
        a.data[x2 + i*a.w + 2*a.w*a.h] = r;
    }
}

void draw_box_width(image a, int x1, int y1, int x2, int y2, int w, float r, float g, float b)
{
    int i;
    for(i = 0; i < w; ++i){
        draw_box(a, x1+i, y1+i, x2-i, y2-i, r, g, b);
    }
}

void flip_image(image a)
{
    int i,j,k;
    for(k = 0; k < a.c; ++k){
        for(i = 0; i < a.h; ++i){
            for(j = 0; j < a.w/2; ++j){
                int index = j + a.w*(i + a.h*(k));
                int flip = (a.w - j - 1) + a.w*(i + a.h*(k));
                float swap = a.data[flip];
                a.data[flip] = a.data[index];
                a.data[index] = swap;
            }
        }
    }
}

image image_distance(image a, image b)
{
    int i,j;
    image dist = make_image(a.w, a.h, 1);
    for(i = 0; i < a.c; ++i){
        for(j = 0; j < a.h*a.w; ++j){
            dist.data[j] += pow(a.data[i*a.h*a.w+j]-b.data[i*a.h*a.w+j],2);
        }
    }
    for(j = 0; j < a.h*a.w; ++j){
        dist.data[j] = sqrt(dist.data[j]);
    }
    return dist;
}

void embed_image(image source, image dest, int dx, int dy)
{
    int x,y,k;
    for(k = 0; k < source.c; ++k){
        for(y = 0; y < source.h; ++y){
            for(x = 0; x < source.w; ++x){
                float val = get_pixel(source, x,y,k);
                set_pixel(dest, dx+x, dy+y, k, val);
            }
        }
    }
}

image collapse_image_layers(image source, int border)
{
    int h = source.h;
    h = (h+border)*source.c - border;
    image dest = make_image(source.w, h, 1);
    int i;
    for(i = 0; i < source.c; ++i){
        image layer = get_image_layer(source, i);
        int h_offset = i*(source.h+border);
        embed_image(layer, dest, 0, h_offset);
        free_image(layer);
    }
    return dest;
}

void constrain_image(image im)
{
    int i;
    for(i = 0; i < im.w*im.h*im.c; ++i){
        if(im.data[i] < 0) im.data[i] = 0;
        if(im.data[i] > 1) im.data[i] = 1;
    }
}

void normalize_image(image p)
{
    float *min = calloc(p.c, sizeof(float));
    float *max = calloc(p.c, sizeof(float));
    int i,j;
    for(i = 0; i < p.c; ++i) min[i] = max[i] = p.data[i*p.h*p.w];

    for(j = 0; j < p.c; ++j){
        for(i = 0; i < p.h*p.w; ++i){
            float v = p.data[i+j*p.h*p.w];
            if(v < min[j]) min[j] = v;
            if(v > max[j]) max[j] = v;
        }
    }
    for(i = 0; i < p.c; ++i){
        if(max[i] - min[i] < .000000001){
            min[i] = 0;
            max[i] = 1;
        }
    }
    for(j = 0; j < p.c; ++j){
        for(i = 0; i < p.w*p.h; ++i){
            p.data[i+j*p.h*p.w] = (p.data[i+j*p.h*p.w] - min[j])/(max[j]-min[j]);
        }
    }
    free(min);
    free(max);
}

image copy_image(image p)
{
    image copy = p;
    copy.data = calloc(p.h*p.w*p.c, sizeof(float));
    memcpy(copy.data, p.data, p.h*p.w*p.c*sizeof(float));
    return copy;
}

void rgbgr_image(image im)
{
    int i;
    for(i = 0; i < im.w*im.h; ++i){
        float swap = im.data[i];
        im.data[i] = im.data[i+im.w*im.h*2];
        im.data[i+im.w*im.h*2] = swap;
    }
}

#ifdef OPENCV
void show_image_cv(image p, char *name)
{
    int x,y,k;
    image copy = copy_image(p);
    constrain_image(copy);
    rgbgr_image(copy);
    //normalize_image(copy);

    char buff[256];
    //sprintf(buff, "%s (%d)", name, windows);
    sprintf(buff, "%s", name);

    IplImage *disp = cvCreateImage(cvSize(p.w,p.h), IPL_DEPTH_8U, p.c);
    int step = disp->widthStep;
    cvNamedWindow(buff, CV_WINDOW_AUTOSIZE); 
    //cvMoveWindow(buff, 100*(windows%10) + 200*(windows/10), 100*(windows%10));
    ++windows;
    for(y = 0; y < p.h; ++y){
        for(x = 0; x < p.w; ++x){
            for(k= 0; k < p.c; ++k){
                disp->imageData[y*step + x*p.c + k] = (unsigned char)(get_pixel(copy,x,y,k)*255);
            }
        }
    }
    free_image(copy);
    if(0){
    //if(disp->height < 448 || disp->width < 448 || disp->height > 1000){
        int w = 448;
        int h = w*p.h/p.w;
        if(h > 1000){
            h = 1000;
            w = h*p.w/p.h;
        }
        IplImage *buffer = disp;
        disp = cvCreateImage(cvSize(w, h), buffer->depth, buffer->nChannels);
        cvResize(buffer, disp, CV_INTER_LINEAR);
        cvReleaseImage(&buffer);
    }
    cvShowImage(buff, disp);
    cvReleaseImage(&disp);
}
#endif

void show_image(image p, char *name)
{
    #ifdef OPENCV
    show_image_cv(p, name);
    #else
    fprintf(stderr, "Not compiled with OpenCV, saving to %s.png instead\n", name);
    save_image(p, name);
    #endif
}

void save_image(image im, char *name)
{
    char buff[256];
    //sprintf(buff, "%s (%d)", name, windows);
    sprintf(buff, "%s.png", name);
    unsigned char *data = calloc(im.w*im.h*im.c, sizeof(char));
    int i,k;
    for(k = 0; k < im.c; ++k){
        for(i = 0; i < im.w*im.h; ++i){
            data[i*im.c+k] = (unsigned char) (255*im.data[i + k*im.w*im.h]);
        }
    }
    int success = stbi_write_png(buff, im.w, im.h, im.c, data, im.w*im.c);
    if(!success) fprintf(stderr, "Failed to write image %s\n", buff);
}

/*
void save_image_cv(image p, char *name)
{
    int x,y,k;
    image copy = copy_image(p);
    //normalize_image(copy);

    char buff[256];
    //sprintf(buff, "%s (%d)", name, windows);
    sprintf(buff, "%s.png", name);

    IplImage *disp = cvCreateImage(cvSize(p.w,p.h), IPL_DEPTH_8U, p.c);
    int step = disp->widthStep;
    for(y = 0; y < p.h; ++y){
        for(x = 0; x < p.w; ++x){
            for(k= 0; k < p.c; ++k){
                disp->imageData[y*step + x*p.c + k] = (unsigned char)(get_pixel(copy,x,y,k)*255);
            }
        }
    }
    free_image(copy);
    cvSaveImage(buff, disp,0);
    cvReleaseImage(&disp);
}
*/

void show_image_layers(image p, char *name)
{
    int i;
    char buff[256];
    for(i = 0; i < p.c; ++i){
        sprintf(buff, "%s - Layer %d", name, i);
        image layer = get_image_layer(p, i);
        show_image(layer, buff);
        free_image(layer);
    }
}

void show_image_collapsed(image p, char *name)
{
    image c = collapse_image_layers(p, 1);
    show_image(c, name);
    free_image(c);
}

image make_empty_image(int w, int h, int c)
{
    image out;
    out.data = 0;
    out.h = h;
    out.w = w;
    out.c = c;
    return out;
}

image make_image(int w, int h, int c)
{
    image out = make_empty_image(w,h,c);
    out.data = calloc(h*w*c, sizeof(float));
    return out;
}

image float_to_image(int w, int h, int c, float *data)
{
    image out = make_empty_image(w,h,c);
    out.data = data;
    return out;
}

image rotate_image(image im, float rad)
{
    int x, y, c;
    float cx = im.w/2.;
    float cy = im.h/2.;
    image rot = make_image(im.w, im.h, im.c);
    for(c = 0; c < im.c; ++c){
        for(y = 0; y < im.h; ++y){
            for(x = 0; x < im.w; ++x){
                float rx = cos(rad)*(x-cx) - sin(rad)*(y-cy) + cx;
                float ry = sin(rad)*(x-cx) + cos(rad)*(y-cy) + cy;
                float val = billinear_interpolate(im, rx, ry, c);
                set_pixel(rot, x, y, c, val);
            }
        }
    }
    return rot;
}

void translate_image(image m, float s)
{
    int i;
    for(i = 0; i < m.h*m.w*m.c; ++i) m.data[i] += s;
}

void scale_image(image m, float s)
{
    int i;
    for(i = 0; i < m.h*m.w*m.c; ++i) m.data[i] *= s;
}

image crop_image(image im, int dx, int dy, int w, int h)
{
    image cropped = make_image(w, h, im.c);
    int i, j, k;
    for(k = 0; k < im.c; ++k){
        for(j = 0; j < h; ++j){
            for(i = 0; i < w; ++i){
                int r = j + dy;
                int c = i + dx;
                float val = 0;
                if (r >= 0 && r < im.h && c >= 0 && c < im.w) {
                    val = get_pixel(im, c, r, k);
                }
                set_pixel(cropped, i, j, k, val);
            }
        }
    }
    return cropped;
}

float three_way_max(float a, float b, float c)
{
    return (a > b) ? ( (a > c) ? a : c) : ( (b > c) ? b : c) ;
}

float three_way_min(float a, float b, float c)
{
    return (a < b) ? ( (a < c) ? a : c) : ( (b < c) ? b : c) ;
}

// http://www.cs.rit.edu/~ncs/color/t_convert.html
void rgb_to_hsv(image im)
{
    assert(im.c == 3);
    int i, j;
    float r, g, b;
    float h, s, v;
    for(j = 0; j < im.h; ++j){
        for(i = 0; i < im.w; ++i){
            r = get_pixel(im, i , j, 0);
            g = get_pixel(im, i , j, 1);
            b = get_pixel(im, i , j, 2);
            float max = three_way_max(r,g,b);
            float min = three_way_min(r,g,b);
            float delta = max - min;
            v = max;
            if(max == 0){
                s = 0;
                h = -1;
            }else{
                s = delta/max;
                if(r == max){
                    h = (g - b) / delta;
                } else if (g == max) {
                    h = 2 + (b - r) / delta;
                } else {
                    h = 4 + (r - g) / delta;
                }
                if (h < 0) h += 6;
            }
            set_pixel(im, i, j, 0, h);
            set_pixel(im, i, j, 1, s);
            set_pixel(im, i, j, 2, v);
        }
    }
}

void hsv_to_rgb(image im)
{
    assert(im.c == 3);
    int i, j;
    float r, g, b;
    float h, s, v;
    float f, p, q, t;
    for(j = 0; j < im.h; ++j){
        for(i = 0; i < im.w; ++i){
            h = get_pixel(im, i , j, 0);
            s = get_pixel(im, i , j, 1);
            v = get_pixel(im, i , j, 2);
            if (s == 0) {
                r = g = b = v;
            } else {
                int index = floor(h);
                f = h - index;
                p = v*(1-s);
                q = v*(1-s*f);
                t = v*(1-s*(1-f));
                if(index == 0){
                    r = v; g = t; b = p;
                } else if(index == 1){
                    r = q; g = v; b = p;
                } else if(index == 2){
                    r = p; g = v; b = t;
                } else if(index == 3){
                    r = p; g = q; b = v;
                } else if(index == 4){
                    r = t; g = p; b = v;
                } else {
                    r = v; g = p; b = q;
                }
            }
            set_pixel(im, i, j, 0, r);
            set_pixel(im, i, j, 1, g);
            set_pixel(im, i, j, 2, b);
        }
    }
}

image grayscale_image(image im)
{
    assert(im.c == 3);
    int i, j, k;
    image gray = make_image(im.w, im.h, im.c);
    float scale[] = {0.587, 0.299, 0.114};
    for(k = 0; k < im.c; ++k){
        for(j = 0; j < im.h; ++j){
            for(i = 0; i < im.w; ++i){
                gray.data[i+im.w*j] += scale[k]*get_pixel(im, i, j, k);
            }
        }
    }
    memcpy(gray.data + im.w*im.h*1, gray.data, sizeof(float)*im.w*im.h);
    memcpy(gray.data + im.w*im.h*2, gray.data, sizeof(float)*im.w*im.h);
    return gray;
}

image blend_image(image fore, image back, float alpha)
{
    assert(fore.w == back.w && fore.h == back.h && fore.c == back.c);
    image blend = make_image(fore.w, fore.h, fore.c);
    int i, j, k;
    for(k = 0; k < fore.c; ++k){
        for(j = 0; j < fore.h; ++j){
            for(i = 0; i < fore.w; ++i){
                float val = alpha * get_pixel(fore, i, j, k) + 
                    (1 - alpha)* get_pixel(back, i, j, k);
                set_pixel(blend, i, j, k, val);
            }
        }
    }
    return blend;
}

void scale_image_channel(image im, int c, float v)
{
    int i, j;
    for(j = 0; j < im.h; ++j){
        for(i = 0; i < im.w; ++i){
            float pix = get_pixel(im, i, j, c);
            pix = pix*v;
            set_pixel(im, i, j, c, pix);
        }
    }
}

void saturate_image(image im, float sat)
{
    rgb_to_hsv(im);
    scale_image_channel(im, 1, sat);
    hsv_to_rgb(im);
    constrain_image(im);
}

void exposure_image(image im, float sat)
{
    rgb_to_hsv(im);
    scale_image_channel(im, 2, sat);
    hsv_to_rgb(im);
    constrain_image(im);
}

void saturate_exposure_image(image im, float sat, float exposure)
{
    rgb_to_hsv(im);
    scale_image_channel(im, 1, sat);
    scale_image_channel(im, 2, exposure);
    hsv_to_rgb(im);
    constrain_image(im);
}

/*
   image saturate_image(image im, float sat)
   {
   image gray = grayscale_image(im);
   image blend = blend_image(im, gray, sat);
   free_image(gray);
   constrain_image(blend);
   return blend;
   }

   image brightness_image(image im, float b)
   {
   image bright = make_image(im.w, im.h, im.c);
   return bright;
   }
 */

float billinear_interpolate(image im, float x, float y, int c)
{
    int ix = (int) floorf(x);
    int iy = (int) floorf(y);

    float dx = x - ix;
    float dy = y - iy;

    float val = (1-dy) * (1-dx) * get_pixel_extend(im, ix, iy, c) + 
        dy     * (1-dx) * get_pixel_extend(im, ix, iy+1, c) + 
        (1-dy) *   dx   * get_pixel_extend(im, ix+1, iy, c) +
        dy     *   dx   * get_pixel_extend(im, ix+1, iy+1, c);
    return val;
}

// #wikipedia
image resize_image(image im, int w, int h)
{
    image resized = make_image(w, h, im.c);   
    int r, c, k;
    float w_scale = (float)(im.w - 1) / (w - 1);
    float h_scale = (float)(im.h - 1) / (h - 1);
    for(k = 0; k < im.c; ++k){
        for(r = 0; r < h; ++r){
            for(c = 0; c < w; ++c){
                float sx = c*w_scale;
                float sy = r*h_scale;
                float val = billinear_interpolate(im, sx, sy, k);
                set_pixel(resized, c, r, k, val);
            }
        }
    }
    return resized;
}

void test_resize(char *filename)
{
    image im = load_image(filename, 0,0, 3);
    image gray = grayscale_image(im);

    image sat2 = copy_image(im);
    saturate_image(sat2, 2);

    image sat5 = copy_image(im);
    saturate_image(sat5, .5);

    image exp2 = copy_image(im);
    exposure_image(exp2, 2);

    image exp5 = copy_image(im);
    exposure_image(exp5, .5);

    show_image(im, "Original");
    show_image(gray, "Gray");
    show_image(sat2, "Saturation-2");
    show_image(sat5, "Saturation-.5");
    show_image(exp2, "Exposure-2");
    show_image(exp5, "Exposure-.5");
    #ifdef OPENCV
    cvWaitKey(0);
    #endif
}

#ifdef OPENCV
image ipl_to_image(IplImage* src)
{
    unsigned char *data = (unsigned char *)src->imageData;
    int h = src->height;
    int w = src->width;
    int c = src->nChannels;
    int step = src->widthStep;
    image out = make_image(w, h, c);
    int i, j, k, count=0;;

    for(k= 0; k < c; ++k){
        for(i = 0; i < h; ++i){
            for(j = 0; j < w; ++j){
                out.data[count++] = data[i*step + j*c + k]/255.;
            }
        }
    }
    return out;
}

image load_image_cv(char *filename, int channels)
{
    IplImage* src = 0;
    int flag = -1;
    if (channels == 0) flag = -1;
    else if (channels == 1) flag = 0;
    else if (channels == 3) flag = 1;
    else {
        fprintf(stderr, "OpenCV can't force load with %d channels\n", channels);
    }
    
    if( (src = cvLoadImage(filename, flag)) == 0 )
    {
        printf("Cannot load file image %s\n", filename);
        exit(0);
    }
    image out = ipl_to_image(src);
    cvReleaseImage(&src);
    rgbgr_image(out);
    return out;
}

#endif


image load_image_stb(char *filename, int channels)
{
    int w, h, c;
    unsigned char *data = stbi_load(filename, &w, &h, &c, channels);
    if (!data) {
        fprintf(stderr, "Cannot load file image %s\nSTB Reason: %s\n", filename, stbi_failure_reason());
        exit(0);
    }
    if(channels) c = channels;
    int i,j,k;
    image im = make_image(w, h, c);
    for(k = 0; k < c; ++k){
        for(j = 0; j < h; ++j){
            for(i = 0; i < w; ++i){
                int dst_index = i + w*j + w*h*k;
                int src_index = k + c*i + c*w*j;
                im.data[dst_index] = (float)data[src_index]/255.;
            }
        }
    }
    free(data);
    return im;
}

image load_image(char *filename, int w, int h, int c)
{
    #ifdef OPENCV
    image out = load_image_cv(filename, c);
    #else
    image out = load_image_stb(filename, c);
    #endif

    if((h && w) && (h != out.h || w != out.w)){
        image resized = resize_image(out, w, h);
        free_image(out);
        out = resized;
    }
    return out;
}

image load_image_color(char *filename, int w, int h)
{
    return load_image(filename, w, h, 3);
}

image get_image_layer(image m, int l)
{
    image out = make_image(m.w, m.h, 1);
    int i;
    for(i = 0; i < m.h*m.w; ++i){
        out.data[i] = m.data[i+l*m.h*m.w];
    }
    return out;
}

float get_pixel(image m, int x, int y, int c)
{
    assert(x < m.w && y < m.h && c < m.c);
    return m.data[c*m.h*m.w + y*m.w + x];
}
float get_pixel_extend(image m, int x, int y, int c)
{
    if(x < 0 || x >= m.w || y < 0 || y >= m.h || c < 0 || c >= m.c) return 0;
    return get_pixel(m, x, y, c);
}
void set_pixel(image m, int x, int y, int c, float val)
{
    assert(x < m.w && y < m.h && c < m.c);
    m.data[c*m.h*m.w + y*m.w + x] = val;
}

void print_image(image m)
{
    int i, j, k;
    for(i =0 ; i < m.c; ++i){
        for(j =0 ; j < m.h; ++j){
            for(k = 0; k < m.w; ++k){
                printf("%.2lf, ", m.data[i*m.h*m.w + j*m.w + k]);
                if(k > 30) break;
            }
            printf("\n");
            if(j > 30) break;
        }
        printf("\n");
    }
    printf("\n");
}

image collapse_images_vert(image *ims, int n)
{
    int color = 1;
    int border = 1;
    int h,w,c;
    w = ims[0].w;
    h = (ims[0].h + border) * n - border;
    c = ims[0].c;
    if(c != 3 || !color){
        w = (w+border)*c - border;
        c = 1;
    }

    image filters = make_image(w, h, c);
    int i,j;
    for(i = 0; i < n; ++i){
        int h_offset = i*(ims[0].h+border);
        image copy = copy_image(ims[i]);
        //normalize_image(copy);
        if(c == 3 && color){
            embed_image(copy, filters, 0, h_offset);
        }
        else{
            for(j = 0; j < copy.c; ++j){
                int w_offset = j*(ims[0].w+border);
                image layer = get_image_layer(copy, j);
                embed_image(layer, filters, w_offset, h_offset);
                free_image(layer);
            }
        }
        free_image(copy);
    }
    return filters;
} 

image collapse_images_horz(image *ims, int n)
{
    int color = 1;
    int border = 1;
    int h,w,c;
    int size = ims[0].h;
    h = size;
    w = (ims[0].w + border) * n - border;
    c = ims[0].c;
    if(c != 3 || !color){
        h = (h+border)*c - border;
        c = 1;
    }

    image filters = make_image(w, h, c);
    int i,j;
    for(i = 0; i < n; ++i){
        int w_offset = i*(size+border);
        image copy = copy_image(ims[i]);
        //normalize_image(copy);
        if(c == 3 && color){
            embed_image(copy, filters, w_offset, 0);
        }
        else{
            for(j = 0; j < copy.c; ++j){
                int h_offset = j*(size+border);
                image layer = get_image_layer(copy, j);
                embed_image(layer, filters, w_offset, h_offset);
                free_image(layer);
            }
        }
        free_image(copy);
    }
    return filters;
} 

void show_images(image *ims, int n, char *window)
{
    image m = collapse_images_vert(ims, n);
    save_image(m, window);
    show_image(m, window);
    free_image(m);
}

void free_image(image m)
{
    free(m.data);
}