Heatmap/Contours based on Transportation Time (Reverse Isochronic Contours) - java

Note: Solutions in r, python, java, or if necessary, c++ or c# are desired.
I am trying to draw contours based on transportation time. To be more clear, I want to cluster the points which have similar travel time (let's say 10 minute interval) to a specific point (destination) and map them as contours or a heatmap.
Right now, the only idea that I have is using R package gmapsdistance to find the travel time for different origins and then cluster them and draw them on a map. But, as you can tell, this is in no way a robust solution.
This thread on GIS-community and this one for python illustrate a similar problem but for an origin to destinations within reach in specific time. I want to find origins which I can travel to the destination within certain time.
Right now, the code below shows my rudimentary idea (using R):
library(gmapsdistance)
set.api.key("YOUR.API.KEY")
mdestination <- "40.7+-73"
morigin1 <- "40.6+-74.2"
morigin2 <- "40+-74"
gmapsdistance(origin = morigin1,
destination = mdestination,
mode = "transit")
gmapsdistance(origin = morigin2,
destination = mdestination,
mode = "transit")
This map also may help to understand the question:
Using this answer I can get the points which I can go to from a point of origin but I need to reverse it and find the points which have travel time equal-less-than a certain time to my destination;
library(httr)
library(googleway)
library(jsonlite)
appId <- "TravelTime_APP_ID"
apiKey <- "TravelTime_API_KEY"
mapKey <- "GOOGLE_MAPS_API_KEY"
location <- c(40, -73)
CommuteTime <- (5 / 6) * 60 * 60
url <- "http://api.traveltimeapp.com/v4/time-map"
requestBody <- paste0('{
"departure_searches" : [
{"id" : "test",
"coords": {"lat":', location[1], ', "lng":', location[2],' },
"transportation" : {"type" : "driving"} ,
"travel_time" : ', CommuteTime, ',
"departure_time" : "2017-05-03T07:20:00z"
}
]
}')
res <- httr::POST(url = url,
httr::add_headers('Content-Type' = 'application/json'),
httr::add_headers('Accept' = 'application/json'),
httr::add_headers('X-Application-Id' = appId),
httr::add_headers('X-Api-Key' = apiKey),
body = requestBody,
encode = "json")
res <- jsonlite::fromJSON(as.character(res))
pl <- lapply(res$results$shapes[[1]]$shell, function(x){
googleway::encode_pl(lat = x[['lat']], lon = x[['lng']])
})
df <- data.frame(polyline = unlist(pl))
df_marker <- data.frame(lat = location[1], lon = location[2])
google_map(key = mapKey) %>%
add_markers(data = df_marker) %>%
add_polylines(data = df, polyline = "polyline")
Moreover, Documentation of Travel Time Map Platform talks about Multi Origins with Arrival time which is exactly the thing I want to do. But I need to do that for both public transportation and driving (for places with less than an hour commute time) and I think since public transport is tricky (based on what station you are close to) maybe heatmap is a better option than contours.

This answer is based on obtaining an origin-destination matrix between a grid of (roughly) equally distant points. This is a computer intensive operation not only because it requires a good number of API calls to mapping services, but also because the servers must calculate a matrix for each call. The number of required calls grows exponentially along the number of points in the grid.
To tackle this problem, I would suggest that you consider running on your local machine or on a local server a mapping server. Project OSRM offers a relatively simple, free, and open-source solution, enabling you to run an OpenStreetMap server into a Linux docker (https://github.com/Project-OSRM/osrm-backend). Having your own local mapping server will allow you to make as many API calls as you desire. R's osrm package allows you to interact with OpenStreetMaps' APIs, Including those placed to a local server.
library(raster) # Optional
library(sp)
library(ggmap)
library(tidyverse)
library(osrm)
devtools::install_github("cmartin/ggConvexHull") # Needed to quickly draw the contours
library(ggConvexHull)
I create a grid of 96 roughly equally distant points around Bruxelles (Belgium) conurbation.
This grid does not take into consideration the earths curvature, which is negligible at the level of city distances.
For convenience, I employ the raster package to download a ShapeFile of Belgium and extract the nodes for Brussels city.
BE <- raster::getData("GADM", country = "BEL", level = 1)
Bruxelles <- BE[BE$NAME_1 == "Bruxelles", ]
df_grid <- makegrid(Bruxelles, cellsize = 0.02) %>%
SpatialPoints() %>%
## I convert the SpatialPoints object into a simple data.frame
as.data.frame() %>%
## create a unique id for each point in the data.frame
rownames_to_column() %>%
## rename variables of the data.frame with more explanatory names.
rename(id = rowname, lat = x2, lon = x1)
## I point osrm.server to the OpenStreet docker running in my Linux machine. ...
### ... Do not run this if you are getting your data from OpenStreet public servers.
options(osrm.server = "http://127.0.0.1:5000/")
## I obtain a list with distances (Origin Destination Matrix in ...
### ... minutes, origins and destinations)
Distance_Tables <- osrmTable(loc = df_grid)
OD_Matrix <- Distance_Tables$durations %>% ## subset the previous list
## convert the Origin Destination Matrix into a tibble
as_data_frame() %>%
rownames_to_column() %>%
## make sure we have an id column for the OD tibble
rename(origin_id = rowname) %>%
## transform the tibble into long/tidy format
gather(key = destination_id, value = distance_time, -origin_id) %>%
left_join(df_grid, by = c("origin_id" = "id")) %>%
## set origin coordinates
rename(origin_lon = lon, origin_lat = lat) %>%
left_join(df_grid, by = c("destination_id" = "id")) %>%
## set destination coordinates
rename(destination_lat = lat, destination_lon = lon)
## Obtain a nice looking road map of Brussels
Brux_map <- get_map(location = "bruxelles, belgique",
zoom = 11,
source = "google",
maptype = "roadmap")
ggmap(Brux_map) +
geom_point(aes(x = origin_lon, y = origin_lat),
data = OD_Matrix %>%
## Here I selected point_id 42 as the desired target, ...
## ... just because it is not far from the City Center.
filter(destination_id == 42),
size = 0.5) +
## Draw a diamond around point_id 42
geom_point(aes(x = origin_lon, y = origin_lat),
data = OD_Matrix %>%
filter(destination_id == 42, origin_id == 42),
shape = 5, size = 3) +
## Countour marking a distance of up to 8 minutes
geom_convexhull(alpha = 0.2,
fill = "blue",
colour = "blue",
data = OD_Matrix %>%
filter(destination_id == 42,
distance_time <= 8),
aes(x = origin_lon, y = origin_lat)) +
## Countour marking a distance of up to 16 minutes
geom_convexhull(alpha = 0.2,
fill = "red",
colour = "red",
data = OD_Matrix %>%
filter(destination_id == 42,
distance_time <= 15),
aes(x = origin_lon, y = origin_lat))
Results
The blue contour represent distances to the city center of up to 8 minutes.
The red contour represent distances of up to 15 minutes.

I came up with an approach that would be applicable comparing to making numerous api calls.
The idea is finding the places you can reach in certain time(look at this thread). Traffic can be simulated by changing the time from morning to evening. You will end up with an overlapped area which you can reach from both places.
Then you can use Nicolas answer and map some points within that overlapped area and draw the heat map for the destinations you have. This way, you will have less area (points) to cover and therefore you will make much less api calls (remember to use appropriate time for that matter).
Below, I tried to demonstrate what I mean by these and get you to the point that you can make the grid mentioned in the other answer to make your estimation more robust.
This shows how to map the intersected area.
library(httr)
library(googleway)
library(jsonlite)
appId <- "Travel.Time.ID"
apiKey <- "Travel.Time.API"
mapKey <- "Google.Map.ID"
locationK <- c(40, -73) #K
locationM <- c(40, -74) #M
CommuteTimeK <- (3 / 4) * 60 * 60
CommuteTimeM <- (0.55) * 60 * 60
url <- "http://api.traveltimeapp.com/v4/time-map"
requestBodyK <- paste0('{
"departure_searches" : [
{"id" : "test",
"coords": {"lat":', locationK[1], ', "lng":', locationK[2],' },
"transportation" : {"type" : "public_transport"} ,
"travel_time" : ', CommuteTimeK, ',
"departure_time" : "2018-06-27T13:00:00z"
}
]
}')
requestBodyM <- paste0('{
"departure_searches" : [
{"id" : "test",
"coords": {"lat":', locationM[1], ', "lng":', locationM[2],' },
"transportation" : {"type" : "driving"} ,
"travel_time" : ', CommuteTimeM, ',
"departure_time" : "2018-06-27T13:00:00z"
}
]
}')
resKi <- httr::POST(url = url,
httr::add_headers('Content-Type' = 'application/json'),
httr::add_headers('Accept' = 'application/json'),
httr::add_headers('X-Application-Id' = appId),
httr::add_headers('X-Api-Key' = apiKey),
body = requestBodyK,
encode = "json")
resMi <- httr::POST(url = url,
httr::add_headers('Content-Type' = 'application/json'),
httr::add_headers('Accept' = 'application/json'),
httr::add_headers('X-Application-Id' = appId),
httr::add_headers('X-Api-Key' = apiKey),
body = requestBodyM,
encode = "json")
resK <- jsonlite::fromJSON(as.character(resKi))
resM <- jsonlite::fromJSON(as.character(resMi))
plK <- lapply(resK$results$shapes[[1]]$shell, function(x){
googleway::encode_pl(lat = x[['lat']], lon = x[['lng']])
})
plM <- lapply(resM$results$shapes[[1]]$shell, function(x){
googleway::encode_pl(lat = x[['lat']], lon = x[['lng']])
})
dfK <- data.frame(polyline = unlist(plK))
dfM <- data.frame(polyline = unlist(plM))
df_markerK <- data.frame(lat = locationK[1], lon = locationK[2], colour = "#green")
df_markerM <- data.frame(lat = locationM[1], lon = locationM[2], colour = "#lavender")
iconK <- "red"
df_markerK$icon <- iconK
iconM <- "blue"
df_markerM$icon <- iconM
google_map(key = mapKey) %>%
add_markers(data = df_markerK,
lat = "lat", lon = "lon",colour = "icon",
mouse_over = "K_K") %>%
add_markers(data = df_markerM,
lat = "lat", lon = "lon", colour = "icon",
mouse_over = "M_M") %>%
add_polygons(data = dfM, polyline = "polyline", stroke_colour = '#461B7E',
fill_colour = '#461B7E', fill_opacity = 0.6) %>%
add_polygons(data = dfK, polyline = "polyline",
stroke_colour = '#F70D1A',
fill_colour = '#FF2400', fill_opacity = 0.4)
You can extract the intersected area like this:
# install.packages(c("rgdal", "sp", "raster","rgeos","maptools"))
library(rgdal)
library(sp)
library(raster)
library(rgeos)
library(maptools)
Kdata <- resK$results$shapes[[1]]$shell
Mdata <- resM$results$shapes[[1]]$shell
xyfunc <- function(mydf) {
xy <- mydf[,c(2,1)]
return(xy)
}
spdf <- function(xy, mydf){
sp::SpatialPointsDataFrame(
coords = xy, data = mydf,
proj4string = CRS("+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0"))}
for (i in (1:length(Kdata))) {Kdata[[i]] <- xyfunc(Kdata[[i]])}
for (i in (1:length(Mdata))) {Mdata[[i]] <- xyfunc(Mdata[[i]])}
Kshp <- list(); for (i in (1:length(Kdata))) {Kshp[i] <- spdf(Kdata[[i]],Kdata[[i]])}
Mshp <- list(); for (i in (1:length(Mdata))) {Mshp[i] <- spdf(Mdata[[i]],Mdata[[i]])}
Kbind <- do.call(bind, Kshp)
Mbind <- do.call(bind, Mshp)
#plot(Kbind);plot(Mbind)
x <- intersect(Kbind,Mbind)
#plot(x)
xdf <- data.frame(x)
xdf$icon <- "https://i.stack.imgur.com/z7NnE.png"
google_map(key = mapKey,
location = c(mean(latmax,latmin), mean(lngmax,lngmin)), zoom = 8) %>%
add_markers(data = xdf, lat = "lat", lon = "lng", marker_icon = "icon")
This is just an illustration of the intersected area.
Now, You can get the coordinates from xdf dataframe and construct your grid around those points to finally come up with a heat map. To respect the other user who came up with that idea/answer I am not including it in mine and am just referencing to it.
Nicolás Velásquez - Obtaining an Origin-Destination Matrix between a Grid of (Roughly) Equally Distant Points

Related

Keras Neural Network output different than Java TensorFlowInferenceInterface output

I have created a neural network in Keras using the InceptionV3 pretrained model:
base_model = applications.inception_v3.InceptionV3(weights='imagenet', include_top=False)
# add a global spatial average pooling layer
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# let's add a fully-connected layer
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I trained the model successfully and want to following image: https://imgur.com/a/hoNjDfR. Therefore, the image is cropped to 299x299 and normalized (just devided by 255):
def img_to_array(img, data_format='channels_last', dtype='float32'):
if data_format not in {'channels_first', 'channels_last'}:
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# Numpy array x has format (height, width, channel)
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def load_image_as_array(path):
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_PIL_INTERPOLATION_METHODS = {
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'bilinear': pil_image.BILINEAR,
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# These methods were only introduced in version 3.4.0 (2016).
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if hasattr(pil_image, 'LANCZOS'):
_PIL_INTERPOLATION_METHODS['lanczos'] = pil_image.LANCZOS
with open(path, 'rb') as f:
img = pil_image.open(io.BytesIO(f.read()))
width_height_tuple = (IMG_HEIGHT, IMG_WIDTH)
resample = _PIL_INTERPOLATION_METHODS['nearest']
img = img.resize(width_height_tuple, resample)
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img_array = load_image_as_array('https://imgur.com/a/hoNjDfR')
img_array = img_array/255
Then I predict it with the trained model in Keras:
predict(img_array.reshape(1,img_array.shape[0],img_array.shape[1],img_array.shape[2]))
The result is the following:
array([[0.02083278, 0.00425783, 0.8858412 , 0.17453966, 0.2628744 ,
0.00428194, 0.2307986 , 0.01038828, 0.07561868, 0.00983179,
0.09568241, 0.03087404, 0.00751176, 0.00651798, 0.03731382,
0.02220723, 0.0187968 , 0.02018479, 0.3416505 , 0.00586909,
0.02030778, 0.01660049, 0.00960067, 0.02457979, 0.9711478 ,
0.00666443, 0.01468313, 0.0035468 , 0.00694743, 0.03057212,
0.00429407, 0.01556832, 0.03173089, 0.01407397, 0.35166138,
0.00734553, 0.0508953 , 0.00336689, 0.0169737 , 0.07512951,
0.00484502, 0.01656419, 0.01643038, 0.02031735, 0.8343202 ,
0.02500874, 0.02459189, 0.01325032, 0.00414564, 0.08371573,
0.00484318]], dtype=float32)
The important point is that it has four values with a value greater than 0.8:
>>> y[y>=0.8]
array([0.9100583 , 0.96635956, 0.91707945, 0.9711707 ], dtype=float32))
Now I have converted my network to .pb and imported it in an android project. I wanted to predict the same image in android. Therefore I also resize the image and normalize it like I did in Python by using the following code:
// Resize image:
InputStream imageStream = getAssets().open("test3.jpg");
Bitmap bitmap = BitmapFactory.decodeStream(imageStream);
Bitmap resized_image = utils.processBitmap(bitmap,299);
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public static float[] normalizeBitmap(Bitmap source,int size){
float[] output = new float[size * size * 3];
int[] intValues = new int[source.getHeight() * source.getWidth()];
source.getPixels(intValues, 0, source.getWidth(), 0, 0, source.getWidth(), source.getHeight());
for (int i = 0; i < intValues.length; ++i) {
final int val = intValues[i];
output[i * 3] = Color.blue(val) / 255.0f;
output[i * 3 + 1] = Color.green(val) / 255.0f;
output[i * 3 + 2] = Color.red(val) / 255.0f ;
}
return output;
}
But in java I get other values. None of the four indices has a value greater than 0.8.
The value of the four indices are between 0.1 and 0.4!!!
I have checked my code several times, but I don't understand why in android I don't get the same values for the same image? Any idea or hint?

How to edit image with opencv to read text with OCR

I'm developing an android app to recognize text in particular plate, as in photo here:
I have to recognize the texts in white (e.g. near to "Mod."). I'm using Google ML Kit's text recognition APIs, but it fails. So, I'm using OpenCV to edit image but I don't know how to emphasize the (white) texts so OCR recognize it. I tried more stuff, like contrast, brightness, gamma correction, adaptive thresholding, but the cases vary a lot depending on how the photo is taken. Do you have any ideas?
Thank u very much.
I coded this example in Python (since OpenCV's SIFT in Android is paid) but you can still use this to understand how to solve it.
First I created this image as a template:
Step 1: Load images
""" 1. Load images """
# load image of plate
src_path = "nRHzD.jpg"
src = cv2.imread(src_path)
# load template of plate (to be looked for)
src_template_path = "nRHzD_template.jpg"
src_template = cv2.imread(src_template_path)
Step 2: Find the template using SIFT and perspective transformation
# convert images to gray scale
src_gray = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
src_template_gray = cv2.cvtColor(src_template, cv2.COLOR_BGR2GRAY)
# use SIFT to find template
n_matches_min = 10
template_found, homography = find_template(src_gray, src_template_gray, n_matches_min)
warp = transform_perspective_and_crop(homography, src, src_gray, src_template)
warp_gray = cv2.cvtColor(warp, cv2.COLOR_BGR2GRAY)
warp_hsv = cv2.cvtColor(warp, cv2.COLOR_BGR2HSV)
template_hsv = cv2.cvtColor(src_template, cv2.COLOR_BGR2HSV)
Step 3: Find regions of interest (using the green parts of the template image)
green_hsv_lower_bound = [50, 250, 250]
green_hsv_upper_bound = [60, 255, 255]
mask_rois, mask_rois_img = crop_img_in_hsv_range(warp, template_hsv, green_hsv_lower_bound, green_hsv_upper_bound)
roi_list = separate_rois(mask_rois, warp_gray)
# sort the rois by distance to top right corner -> x (value[1]) + y (value[2])
roi_list = sorted(roi_list, key=lambda values: values[1]+values[2])
Step 4: Apply a Canny Edge detection to the rois (regions of interest)
for i, roi in enumerate(roi_list):
roi_img, roi_x_offset, roi_y_offset = roi
print("#roi:{} x:{} y:{}".format(i, roi_x_offset, roi_y_offset))
roi_img_blur_threshold = cv2.Canny(roi_img, 40, 200)
cv2.imshow("ROI image", roi_img_blur_threshold)
cv2.waitKey()
There are many ways for you to detect the digits, one of the easiest approaches is to run a K-Means Clustering on each of the contours.
Full code:
""" This code shows a way of getting the digit's edges in a pre-defined position (in green) """
import cv2
import numpy as np
def find_template(src_gray, src_template_gray, n_matches_min):
# Initiate SIFT detector
sift = cv2.xfeatures2d.SIFT_create()
""" find grid using SIFT """
# find the keypoints and descriptors with SIFT
kp1, des1 = sift.detectAndCompute(src_template_gray, None)
kp2, des2 = sift.detectAndCompute(src_gray, None)
FLANN_INDEX_KDTREE = 0
index_params = dict(algorithm = FLANN_INDEX_KDTREE, trees = 5)
search_params = dict(checks = 50)
flann = cv2.FlannBasedMatcher(index_params, search_params)
matches = flann.knnMatch(des1, des2, k=2)
# store all the good matches as per Lowe's ratio test.
good = []
for m,n in matches:
if m.distance < 0.7*n.distance:
good.append(m)
if len(good) > n_matches_min:
src_pts = np.float32([kp1[m.queryIdx].pt for m in good ]).reshape(-1,1,2)
dst_pts = np.float32([kp2[m.trainIdx].pt for m in good ]).reshape(-1,1,2)
M, mask = cv2.findHomography(src_pts, dst_pts, cv2.RANSAC,5.0)
matchesMask = mask.ravel().tolist()
h_template, w_template = src_template_gray.shape
pts = np.float32([[0, 0], [0, h_template - 1], [w_template - 1, h_template - 1], [w_template - 1,0]]).reshape(-1,1,2)
homography = cv2.perspectiveTransform(pts, M)
else:
print "Not enough matches are found - %d/%d" % (len(good), n_matches_min)
matchesMask = None
# show matches
draw_params = dict(matchColor = (0, 255, 0), # draw matches in green color
singlePointColor = None,
matchesMask = matchesMask, # draw only inliers
flags = 2)
if matchesMask:
src_gray_copy = src_gray.copy()
sift_matches = cv2.polylines(src_gray_copy, [np.int32(homography)], True, 255, 2, cv2.LINE_AA)
sift_matches = cv2.drawMatches(src_template_gray, kp1, src_gray_copy, kp2, good, None, **draw_params)
return sift_matches, homography
def transform_perspective_and_crop(homography, src, src_gray, src_template_gray):
""" get mask and contour of template """
mask_img_template = np.zeros(src_gray.shape, dtype=np.uint8)
mask_img_template = cv2.polylines(mask_img_template, [np.int32(homography)], True, 255, 1, cv2.LINE_AA)
_ret, contours, hierarchy = cv2.findContours(mask_img_template, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
template_contour = None
# approximate the contour
c = contours[0]
peri = cv2.arcLength(c, True)
approx = cv2.approxPolyDP(c, 0.02 * peri, True)
# if our approximated contour has four points, then
# we can assume that we have found our template
warp = None
if len(approx) == 4:
template_contour = approx
cv2.drawContours(mask_img_template, [template_contour] , -1, (255,0,0), -1)
""" Transform perspective """
# now that we have our template contour, we need to determine
# the top-left, top-right, bottom-right, and bottom-left
# points so that we can later warp the image -- we'll start
# by reshaping our contour to be our finals and initializing
# our output rectangle in top-left, top-right, bottom-right,
# and bottom-left order
pts = template_contour.reshape(4, 2)
rect = np.zeros((4, 2), dtype = "float32")
# the top-left point has the smallest sum whereas the
# bottom-right has the largest sum
s = pts.sum(axis = 1)
rect[0] = pts[np.argmin(s)]
rect[2] = pts[np.argmax(s)]
# compute the difference between the points -- the top-right
# will have the minumum difference and the bottom-left will
# have the maximum difference
diff = np.diff(pts, axis = 1)
rect[1] = pts[np.argmin(diff)]
rect[3] = pts[np.argmax(diff)]
# now that we have our rectangle of points, let's compute
# the width of our new image
(tl, tr, br, bl) = rect
widthA = np.sqrt(((br[0] - bl[0]) ** 2) + ((br[1] - bl[1]) ** 2))
widthB = np.sqrt(((tr[0] - tl[0]) ** 2) + ((tr[1] - tl[1]) ** 2))
# ...and now for the height of our new image
heightA = np.sqrt(((tr[0] - br[0]) ** 2) + ((tr[1] - br[1]) ** 2))
heightB = np.sqrt(((tl[0] - bl[0]) ** 2) + ((tl[1] - bl[1]) ** 2))
# take the maximum of the width and height values to reach
# our final dimensions
maxWidth = max(int(widthA), int(widthB))
maxHeight = max(int(heightA), int(heightB))
# construct our destination points which will be used to
# map the screen to a top-down, "birds eye" view
homography = np.array([
[0, 0],
[maxWidth - 1, 0],
[maxWidth - 1, maxHeight - 1],
[0, maxHeight - 1]], dtype = "float32")
# calculate the perspective transform matrix and warp
# the perspective to grab the screen
M = cv2.getPerspectiveTransform(rect, homography)
warp = cv2.warpPerspective(src, M, (maxWidth, maxHeight))
# resize warp
h_template, w_template, _n_channels = src_template_gray.shape
warp = cv2.resize(warp, (w_template, h_template), interpolation=cv2.INTER_AREA)
return warp
def crop_img_in_hsv_range(img, hsv, lower_bound, upper_bound):
mask = cv2.inRange(hsv, np.array(lower_bound), np.array(upper_bound))
# do an MORPH_OPEN (erosion followed by dilation) to remove isolated pixels
kernel = np.ones((5,5), np.uint8)
mask = cv2.morphologyEx(mask, cv2.MORPH_OPEN, kernel)
# Bitwise-AND mask and original image
res = cv2.bitwise_and(img, img, mask=mask)
return mask, res
def separate_rois(column_mask, img_gray):
# go through each of the boxes
# https://stackoverflow.com/questions/41592039/contouring-a-binary-mask-with-opencv-python
border = cv2.copyMakeBorder(column_mask, 1, 1, 1, 1, cv2.BORDER_CONSTANT, value=0)
_, contours, hierarchy = cv2.findContours(border, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE, offset=(-1, -1))
cell_list = []
for contour in contours:
cell_mask = np.zeros_like(img_gray) # Create mask where white is what we want, black otherwise
cv2.drawContours(cell_mask, [contour], -1, 255, -1) # Draw filled contour in mask
# turn that mask into a rectangle
(x,y,w,h) = cv2.boundingRect(contour)
#print("x:{} y:{} w:{} h:{}".format(x, y, w, h))
cv2.rectangle(cell_mask, (x, y), (x+w, y+h), 255, -1)
# copy the img_gray using that mask
img_tmp_region = cv2.bitwise_and(img_gray, img_gray, mask= cell_mask)
# Now crop
(y, x) = np.where(cell_mask == 255)
(top_y, top_x) = (np.min(y), np.min(x))
(bottom_y, bottom_x) = (np.max(y), np.max(x))
img_tmp_region = img_tmp_region[top_y:bottom_y+1, top_x:bottom_x+1]
cell_list.append([img_tmp_region, top_x, top_y])
return cell_list
""" 1. Load images """
# load image of plate
src_path = "nRHzD.jpg"
src = cv2.imread(src_path)
# load template of plate (to be looked for)
src_template_path = "nRHzD_template.jpg"
src_template = cv2.imread(src_template_path)
""" 2. Find the plate (using the template image) and crop it into a rectangle """
# convert images to gray scale
src_gray = cv2.cvtColor(src, cv2.COLOR_BGR2GRAY)
src_template_gray = cv2.cvtColor(src_template, cv2.COLOR_BGR2GRAY)
# use SIFT to find template
n_matches_min = 10
template_found, homography = find_template(src_gray, src_template_gray, n_matches_min)
warp = transform_perspective_and_crop(homography, src, src_gray, src_template)
warp_gray = cv2.cvtColor(warp, cv2.COLOR_BGR2GRAY)
warp_hsv = cv2.cvtColor(warp, cv2.COLOR_BGR2HSV)
template_hsv = cv2.cvtColor(src_template, cv2.COLOR_BGR2HSV)
""" 3. Find regions of interest (using the green parts of the template image) """
green_hsv_lower_bound = [50, 250, 250]
green_hsv_upper_bound = [60, 255, 255]
mask_rois, mask_rois_img = crop_img_in_hsv_range(warp, template_hsv, green_hsv_lower_bound, green_hsv_upper_bound)
roi_list = separate_rois(mask_rois, warp_gray)
# sort the rois by distance to top right corner -> x (value[1]) + y (value[2])
roi_list = sorted(roi_list, key=lambda values: values[1]+values[2])
""" 4. Apply a Canny Edge detection to the rois (regions of interest) """
for i, roi in enumerate(roi_list):
roi_img, roi_x_offset, roi_y_offset = roi
print("#roi:{} x:{} y:{}".format(i, roi_x_offset, roi_y_offset))
roi_img_blur_threshold = cv2.Canny(roi_img, 40, 200)
cv2.imshow("ROI image", roi_img_blur_threshold)
cv2.waitKey()

Tensorflow in Android: How do i use my linear regression model to predict a value in an android application?

I currently have a ipynb file (ipython notebook) that contains a linear regression code / model(im not entirely sure if it's a model) that I've created earlier.
How do i implement this model in an android application such that if I were to input a value of 'x' in a text box, it'll output in a textview the predicted value of 'y'. Function: Y = mx + b.
I've tried looking at different tutorials, but they were mostly not "step-by-step" guides, which made it really hard to understand, I'm a beginner at coding.
Here's my code for the model:
import tensorflow as tf
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
%matplotlib inline
rng = np.random
from numpy import genfromtxt
from sklearn.datasets import load_boston
# Parameters
learning_rate = 0.0001
training_epochs = 1000
display_step = 50
n_samples = 222
X = tf.placeholder("float") # create symbolic variables
Y = tf.placeholder("float")
filename_queue = tf.train.string_input_producer(["C://Users//Shiina//battdata.csv"],shuffle=False)
reader = tf.TextLineReader() # skip_header_lines=1 if csv has headers
key, value = reader.read(filename_queue)
# Default values, in case of empty columns. Also specifies the type of the
# decoded result.
record_defaults = [[1.], [1.]]
height, soc= tf.decode_csv(
value, record_defaults=record_defaults)
features = tf.stack([height])
# Set model weights
W = tf.Variable(rng.randn(), name="weight")
b = tf.Variable(rng.randn(), name="bias")
# Construct a linear model
pred_soc = tf.add(tf.multiply(height, W), b) # XW + b <- y = mx + b where W is gradient, b is intercept
# Mean squared error
cost = tf.reduce_sum(tf.pow(pred_soc-soc, 2))/(2*n_samples)
# Gradient descent
optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)
# Initializing the variables
init = tf.global_variables_initializer()
with tf.Session() as sess:
# Start populating the filename queue.
coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(coord=coord)
sess.run(init)
# Fit all training data
for epoch in range(training_epochs):
_, cost_value = sess.run([optimizer,cost])
#Display logs per epoch step
if (epoch+1) % display_step == 0:
c = sess.run(cost)
print( "Epoch:", '%04d' % (epoch+1), "cost=", "{:.9f}".format(c), \
"W=", sess.run(W), "b=", sess.run(b))
print("Optimization Finished!")
training_cost = sess.run(cost)
print ("Training cost=", training_cost, "W=", sess.run(W), "b=", sess.run(b), '\n')
#Plot data after completing training
train_X = []
train_Y = []
for i in range(n_samples): #Your input data size to loop through once
X, Y = sess.run([height, pred_soc]) # Call pred, to get the prediction with the updated weights
train_X.append(X)
train_Y.append(Y)
#Graphic display
plt.plot(train_X, train_Y, 'ro', label='Original data')
plt.ylabel("SoC")
plt.xlabel("Height")
plt.axis([0, 1, 0, 100])
plt.plot(train_X, train_Y, linewidth=2.0)
plt.legend()
plt.show()
coord.request_stop()
coord.join(threads)

R text mining: error in extracting bigrams from corpus during tokenization step

Fetching data from url:
suppressMessages(library(readr))
suppressMessages(library(RCurl))
amazon_url <- getURL('http://s3.amazonaws.com/assets.datacamp.com/production/course_935/datasets/500_amzn.csv',
ssl.verifyhost=FALSE, ssl.verifypeer=FALSE)
amazon <- read.csv(textConnection(amazon_url), header = TRUE)
Create amzn_cons:
amazon_cons <- amazon$cons
Build cleaning function based qdap package for text organization:
suppressWarnings(library(qdap))
qdap_clean <- function(x) {
x <- replace_abbreviation(x)
x <- replace_contraction(x)
x <- replace_number(x)
x <- replace_ordinal(x)
x <- replace_symbol(x)
x <- tolower(x)
return(x)
}
Build cleaning function based on tm package for text organization:
suppressWarnings(library(tm))
tm_clean <- function(corpus) {
corpus<- tm_map(corpus, removePunctuation)
corpus <- tm_map(corpus, stripWhitespace)
corpus <- tm_map(corpus, removeWords,
c(stopwords("en"), "Amazon","company"))
return(corpus)
}
Word cleaning:
amzn_cons <- qdap_clean(amazon_cons)
amzn_cons <- VCorpus(VectorSource(amzn_cons))
amzn_cons_corp <- tm_clean(amzn_cons)
Build custom function to extract bigram features:
suppressWarnings(library(RWeka))
tokenizer <- function(x)
NGramTokenizer(x, Weka_control(min = 2, max = 2))
Apply tokenization function to get bigrams words:
amzn_c_tdm <- TermDocumentMatrix(
amzn_cons_corp,control = list(tokenize = tokenizer) )
This results in the following error:
Error in .jcall("RWekaInterfaces", "[S", "tokenize", .jcast(tokenizer, :
java.lang.NullPointerException
How to solve this error?

How can i extract components from fastICA

I have problems to get ICA component fastICA in R. when i try to extract 6 component from fastICA function it give only one component but there should be 6 components . upto 5 it was worked perfectly but after the 5 it gives different different number of components.can anyone tell me what is the reason for that
Function and Parameters:
ICA6 <- fastICA(X, 6, alg.typ = "parallel", fun = "logcosh", alpha = 1,
method = "R", row.norm = FALSE, maxit = 200, tol = 0.0001, verbose = TRUE)
here is the last few lines of my output for ICA6 and ICA5
hpc-admin#aiken:~/gayan$ tail ICA6
[1992,] -1.755614e-01
[1993,] -1.931838e-01
[1994,] -1.403488e-01
[1995,] 4.952370e-01
[1996,] 3.798545e-02
[1997,] -8.870945e-02
[1998,] -1.847535e-01
[1999,] 2.084906e-01
[2000,] 2.235841e-01
hpc-admin#aiken:~/gayan$ tail ICA5
[1992,] -4.449966e-02 2.348224e-02 -0.1296879740 4.220189e-02 -0.1751827781
[1993,] -7.690094e-02 1.725353e-02 -0.1153838819 1.694351e-01 -0.1308105118
[1994,] -4.777415e-02 2.299214e-02 -0.1259907838 -6.011591e-03 -0.1605316621
[1995,] 4.354237e-02 2.295694e-02 -0.2499377363 -2.227481e-01 0.4414782035
[1996,] -3.848286e-02 2.121986e-02 -0.1361600020 -8.448882e-02 -0.0005046113
[1997,] -3.030994e-03 2.285310e-02 -0.1407370888 -1.215308e-02 -0.1062227838
[1998,] -3.988264e-03 2.335983e-02 -0.1497881709 1.787074e-02 -0.1982725941
[1999,] -7.483824e-02 1.096696e-02 -0.0672348301 -1.665848e-01 0.1489732404
[2000,] -7.123032e-01 1.123832e-02 0.5153474842 -1.785166e-01 0.1632015019

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