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-rw-r--r--img/force_field_transform.jl135
-rw-r--r--img/force_field_transform.py126
-rw-r--r--img/force_field_transform_fft.jl29
-rw-r--r--img/forcefield.jl87
-rw-r--r--img/png2gif.sh11
5 files changed, 388 insertions, 0 deletions
diff --git a/img/force_field_transform.jl b/img/force_field_transform.jl
new file mode 100644
index 0000000..1b3872a
--- /dev/null
+++ b/img/force_field_transform.jl
@@ -0,0 +1,135 @@
+#!/usr/bin/env julia
+# -*- coding: utf-8 -*-
+#
+# Force field transform
+#
+# Aaron LI
+# 2015/07/14
+#
+
+using FITSIO;
+#include("../julia/ndgrid.jl");
+
+@everywhere function meshgrid(vx, vy)
+ m, n = length(vy), length(vx)
+ vx = reshape(vx, 1, n)
+ vy = reshape(vy, m, 1)
+ (repmat(vx, m, 1), repmat(vy, 1, n))
+end
+
+
+# Calculate the forces between the specified point with respect to the image.
+@everywhere function force(p0, img)
+ img = copy(img);
+ x0, y0 = p0;
+ v0 = img[y0, x0];
+ img[y0, x0] = 0.0;
+ rows, cols = size(img);
+ x, y = meshgrid(1:cols, 1:rows);
+ x[y0, x0] = -1;
+ y[y0, x0] = -1;
+ f_x = v0 .* img .* (x-x0) ./ ((x-x0).^2 + (y-y0).^2).^1.5;
+ f_y = v0 .* img .* (y-y0) ./ ((x-x0).^2 + (y-y0).^2).^1.5;
+ #return (f_x, f_y);
+ return (sum(f_x), sum(f_y));
+end
+
+
+# Perform the "force field transform" for the input image.
+#
+# Return:
+# (amplitudes, angles)
+# amplitudes: the amplitudes of the resulting forces of each pixel
+# angles: the directions of the resulting forces of each pixel,
+# in unit radian.
+@everywhere function force_field_transform_serial(img, rowstart=1, rowend="end")
+ rows, cols = size(img)
+ if rowend == "end"
+ rowend = rows
+ end
+ amplitudes = zeros(rows, cols)
+ angles = zeros(rows, cols)
+ t0 = time()
+ t_p = t0 + 30 # in 30 seconds
+ for y = rowstart:rowend
+ for x = 1:cols
+ t1 = time()
+ if (t1 >= t_p)
+ percent = 100*((y-rowstart)*cols + x+1) / ((rowend-rowstart+1)*cols)
+ @printf("Worker #%d: progress: %.3f%%; %.1f min\n",
+ myid(), percent, (t1-t0)/60.0)
+ t_p += 30 # in 30 seconds
+ end
+ F_x, F_y = force((x, y), img)
+ #@printf("F_x, F_y = (%f, %f)\n", F_x, F_y);
+ amplitudes[y, x] = sqrt(F_x^2 + F_y^2)
+ angles[y, x] = atan2(F_y, F_x)
+ end
+ end
+ t1 = time()
+ @printf("Worker #%d: finished in %.1f min!\n", myid(), (t1-t0)/60.0)
+ return (amplitudes, angles)
+end
+
+
+# parallel-capable
+function force_field_transform(img)
+ t0 = time()
+ rows, cols = size(img)
+ np = nprocs()
+ amplitudes = cell(np)
+ angles = cell(np)
+ # split rows for each process
+ rows_chunk = div(rows, np)
+ rowstart = cell(np)
+ rowend = cell(np)
+ @sync begin
+ for p = 1:np
+ rowstart[p] = 1 + rows_chunk * (p-1)
+ if p == np
+ rowend[p] = rows
+ else
+ rowend[p] = rowstart[p] + rows_chunk - 1
+ end
+ # perform transform
+ @async begin
+ amplitudes[p], angles[p] = remotecall_fetch(p,
+ force_field_transform_serial,
+ img, rowstart[p], rowend[p])
+ end
+ end
+ end
+ t1 = time()
+ @printf("Finished in %.1f min!\n", (t1-t0)/60.0)
+ return (sum(amplitudes), sum(angles))
+end
+
+
+# arguments
+#println(ARGS);
+if length(ARGS) != 3
+ println("Usage: PROG <input_fits_img> <out_fits_amplitudes> <out_fits_angles>");
+ exit(1);
+end
+
+infile = ARGS[1];
+outfile_ampl = ARGS[2];
+outfile_angles = ARGS[3];
+
+fits_img = FITS(infile);
+img = read(fits_img[1]);
+header = read_header(fits_img[1]);
+
+# perform force field transform
+ampl, angles = force_field_transform(img);
+
+outfits_ampl = FITS(outfile_ampl, "w");
+outfits_angles = FITS(outfile_angles, "w");
+write(outfits_ampl, ampl; header=header);
+write(outfits_angles, angles; header=header);
+
+close(fits_img);
+close(outfits_ampl);
+close(outfits_angles);
+
+#= vim: set ts=8 sw=4 tw=0 fenc=utf-8 ft=julia: =#
diff --git a/img/force_field_transform.py b/img/force_field_transform.py
new file mode 100644
index 0000000..2b185c8
--- /dev/null
+++ b/img/force_field_transform.py
@@ -0,0 +1,126 @@
+# -*- coding: utf -*-
+#
+# Force field transform (Hurley et al., 2002, 2005)
+#
+
+"""
+Force field transform
+"""
+
+import sys
+import time
+import numpy as np
+
+
+def force(p1, p2):
+ """
+ The force between two points of the image.
+
+ Arguments:
+ p1, p2: (value, x, y)
+
+ Return:
+ # (force, angle): value and direction of the force.
+ # angle: (-pi, pi], with respect to p1.
+ (f_x, f_y): x and y components of the force
+ """
+ v1, x1, y1 = p1
+ v2, x2, y2 = p2
+ #force = v1*v2 / ((x1-x2)**2 + (y1-y2)**2)
+ #angle = np.atan2(y2-y1, x2-x1)
+ #return (force, angle)
+ f_x = v1 * v2 * (x2-x1) / ((x2-x1)**2 + (y2-y1)**2)**1.5
+ f_y = v1 * v2 * (y2-y1) / ((x2-x1)**2 + (y2-y1)**2)**1.5
+ return (f_x, f_y)
+
+
+def force_array(p0, img):
+ """
+ The forces between the input point with respect to the image.
+
+ Arguments:
+ p0: (x, y), note (x, y) start with zero.
+ img: input image, a numpy array
+
+ Return:
+ (f_x, f_y): x and y components of the forces of the same size
+ of the input image
+ """
+ x0, y0 = p0
+ v0 = img[y0, x0]
+ img[y0, x0] = 0.0
+ x, y = np.meshgrid(range(img.shape[1]), range(img.shape[0]))
+ x[y0, x0] = -1
+ y[y0, x0] = -1
+ f_x = v0 * img * (x-x0) / ((x-x0)**2 + (y-y0)**2)**1.5
+ f_y = v0 * img * (y-y0) / ((x-x0)**2 + (y-y0)**2)**1.5
+ return (f_x, f_y)
+
+
+def vector_add(v1, v2):
+ """
+ Add two vectors and return the results.
+
+ Arguments:
+ v1, v2: two input vectors of format (f_x, f_y)
+
+ Return:
+ (F_x, F_y)
+ """
+ f1_x, f1_y = v1
+ f2_x, f2_y = v2
+ return (f1_x+f2_x, f1_y+f2_y)
+
+
+def force_summation(pixel, img):
+ """
+ Calculate the resulting force of the specified pixel with respect to
+ the image.
+
+ Argument:
+ pixel: the position (x, y) of the pixel to be calculated
+ img: the input image
+
+ Return:
+ (F_x, F_y): x and y components of the resulting force.
+ """
+ img = np.array(img)
+ x0, y0 = pixel
+ f_x, f_y = force_array((x0, y0), img)
+ return (f_x.sum(), f_y.sum())
+
+
+def force_field_transform(img):
+ """
+ Perform the "force field transform" on the input image.
+
+ Arguments:
+ img: input 2D image
+
+ Return:
+ (amplitudes, angles)
+ amplitudes: the amplitudes of the resulting forces of each pixel
+ angles: the directions of the resulting forces of each pixel,
+ in unit radian.
+ """
+ img = np.array(img)
+ amplitudes = np.zeros(img.shape)
+ angles = np.zeros(img.shape)
+ rows, cols = img.shape
+ t0 = time.time()
+ t_p = t0 + 30 # in 30 seconds
+ for y in range(rows):
+ for x in range(cols):
+ t1 = time.time()
+ if t1 >= t_p:
+ percent = 100 * (y*cols + x + 1) / (rows * cols)
+ print("progress: %.3f%%; %.1f min" % (percent, (t1-t0)/60.0),
+ file=sys.stderr)
+ t_p += 30 # in 30 seconds
+ f_x, f_y = force_array((x, y), img)
+ F_x, F_y = f_x.sum(), f_y.sum()
+ amplitudes[y, x] = np.sqrt(F_x**2 + F_y**2)
+ angles[y, x] = np.math.atan2(F_y, F_x)
+ return (amplitudes, angles)
+
+
diff --git a/img/force_field_transform_fft.jl b/img/force_field_transform_fft.jl
new file mode 100644
index 0000000..c5bf905
--- /dev/null
+++ b/img/force_field_transform_fft.jl
@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+#
+# To do force field transform using FFT
+#
+# Aaron LI
+# 2015/07/16
+#
+
+function forcefieldtransform_fft(img)
+ rows, cols = size(img)
+ pic = zeros(3*rows, 3*cols)
+ pic[1:rows, 1:cols] = img
+ # unit force field
+ unit_ff = complex(zeros(3*rows, 3*cols))
+ for r = 1:(2*rows-1)
+ for c = 1:(2*cols)
+ d = (rows+cols*im) - (r+c*im)
+ if (r, c) == (rows, cols)
+ unit_ff[r, c] = 0 + 0im
+ else
+ unit_ff[r, c] = d / abs(d)^3
+ end
+ end
+ end
+ # FIXME matrix sizes
+ ff = sqrt(rows*cols) * ifft(fft(pic) .* fft(unit_ff))
+ #ff_crop = ff[rows:2*rows, cols:2*cols]
+end
+
diff --git a/img/forcefield.jl b/img/forcefield.jl
new file mode 100644
index 0000000..bf2c236
--- /dev/null
+++ b/img/forcefield.jl
@@ -0,0 +1,87 @@
+# -*- coding: utf-8 -*-
+#
+# Force field transform with specified size of mask.
+#
+# Aaron LI
+# 2015/07/19
+#
+
+# Make the specified sized force field mask.
+# NOTE: the number of rows and cols must be odd.
+function ff_mask(rows=5, cols=5)
+ rows % 2 == 1 || error("rows must be odd number")
+ cols % 2 == 1 || error("cols must be odd number")
+ mask = complex(zeros(rows, cols))
+ for r = range(-div(rows, 2), rows)
+ for c = range(-div(cols, 2), cols)
+ i, j = r + div(rows+1, 2), c + div(cols+1, 2)
+ #@printf("(r,c) = (%d,%d); (i,j) = (%d,%d)\n", r, c, i, j)
+ d = c + r*im
+ if abs(d) < 1e-8
+ mask[i, j] = 0.0
+ else
+ mask[i, j] = d / abs(d)^3
+ end
+ end
+ end
+ return mask / sum(abs(mask))
+end
+
+
+# Padding image by specified number of rows and cols.
+# Default padding mode: mirror
+function pad_image(img, pad_rows, pad_cols, mode="mirror")
+ rows, cols = size(img)
+ rows_new, cols_new = rows + 2*pad_rows, cols + 2*pad_cols
+ img_pad = zeros(rows_new, cols_new)
+ img_pad[(pad_rows+1):(pad_rows+rows), (pad_cols+1):(pad_cols+cols)] = img
+ for r = 1:rows_new
+ for c = 1:cols_new
+ if mode == "mirror"
+ if r <= pad_rows
+ r_mirror = 2*(pad_rows+1) - r
+ elseif r <= pad_rows+rows
+ r_mirror = r
+ else
+ r_mirror = 2*(pad_rows+rows) - r
+ end
+ if c <= pad_cols
+ c_mirror = 2*(pad_cols+1) - c
+ elseif c <= pad_cols+cols
+ c_mirror = c
+ else
+ c_mirror = 2*(pad_cols+cols) - c
+ end
+ if (r_mirror, c_mirror) != (r, c)
+ #@printf("(%d,%d) <= (%d,%d)\n", r, c, r_mirror, c_mirror)
+ img_pad[r, c] = img_pad[r_mirror, c_mirror]
+ end
+ else
+ error("mode not supported")
+ end
+ end
+ end
+ return img_pad
+end
+
+
+# Perform force field transform for the image.
+function ff_transform(img, mask, mode="mirror")
+ rows, cols = size(img)
+ mask_rows, mask_cols = size(mask)
+ pad_rows, pad_cols = div(mask_rows, 2), div(mask_cols, 2)
+ img_pad = pad_image(img, pad_rows, pad_cols)
+ # result images
+ ff_amplitudes = zeros(rows, cols)
+ ff_angles = zeros(rows, cols)
+ # calculate transformed values
+ for r = (pad_rows+1):(pad_rows+rows)
+ for c = (pad_cols+1):(pad_cols+cols)
+ force = sum(img_pad[r, c] * img_pad[(r-pad_rows):(r+pad_rows), (c-pad_cols):(c+pad_cols)] .* mask)
+ ff_amplitudes[r-pad_rows, c-pad_cols] = abs(force)
+ ff_angles[r-pad_rows, c-pad_cols] = angle(force)
+ end
+ end
+ return ff_amplitudes, ff_angles
+end
+
diff --git a/img/png2gif.sh b/img/png2gif.sh
new file mode 100644
index 0000000..1357be3
--- /dev/null
+++ b/img/png2gif.sh
@@ -0,0 +1,11 @@
+#!/bin/sh
+
+#convert ???.png -background white -alpha remove -resize 50% -layers optimize -delay 5 -loop 0 simu.gif
+
+[ ! -d gifs ] && mkdir gifs
+
+for f in ???.png; do
+ convert $f -trim -resize 50% gifs/${f%.png}.gif
+done
+gifsicle --delay=5 --loop --colors=256 --optimize=3 gifs/???.gif > simu.gif
+