Image not segmenting properly using DBSCAN - opencv

I am trying to use DBSCAN from scikitlearn to segment an image based on color. The results I'm getting are . As you can see there are 3 clusters. My goal is to separate the buoys in the picture into different clusters. But obviously they are showing up as the same cluster. I've tried a wide range of eps values and min_samples but those two things always cluster together. My code is:
img= cv2.imread("buoy1.jpg)
labimg = cv2.cvtColor(img, cv2.COLOR_BGR2LAB)
n = 0
while(n<4):
labimg = cv2.pyrDown(labimg)
n = n+1
feature_image=np.reshape(labimg, [-1, 3])
rows, cols, chs = labimg.shape
db = DBSCAN(eps=5, min_samples=50, metric = 'euclidean',algorithm ='auto')
db.fit(feature_image)
labels = db.labels_
plt.figure(2)
plt.subplot(2, 1, 1)
plt.imshow(img)
plt.axis('off')
plt.subplot(2, 1, 2)
plt.imshow(np.reshape(labels, [rows, cols]))
plt.axis('off')
plt.show()
I assume this is taking the euclidean distance and since its in lab space euclidean distance would be different between different colors. If anyone can give me guidance on this I'd really appreciate it.
Update:
The below answer works. Since DBSCAN requires an array with no more then 2 dimensions I concatenated the columns to the original image and reshaped to produce a n x 5 matrix where n is the x dimension times the y dimension. This seems to work for me.
indices = np.dstack(np.indices(img.shape[:2]))
xycolors = np.concatenate((img, indices), axis=-1)
np.reshape(xycolors, [-1,5])

You need to use both color and position.
Right now, you are using colors only.

Could you please add the enitre code in the answer? Im not able to understand where do I add the those 3 lines which have worked for you – user8306074 Sep 4 at 8:58
Let me answer for you, and here is the full version of the code:
import numpy as np
import cv2
import matplotlib.pyplot as plt
from sklearn.cluster import DBSCAN
img= cv2.imread('your image')
labimg = cv2.cvtColor(img, cv2.COLOR_BGR2LAB)
n = 0
while(n<4):
labimg = cv2.pyrDown(labimg)
n = n+1
feature_image=np.reshape(labimg, [-1, 3])
rows, cols, chs = labimg.shape
db = DBSCAN(eps=5, min_samples=50, metric = 'euclidean',algorithm ='auto')
db.fit(feature_image)
labels = db.labels_
indices = np.dstack(np.indices(labimg.shape[:2]))
xycolors = np.concatenate((labimg, indices), axis=-1)
feature_image2 = np.reshape(xycolors, [-1,5])
db.fit(feature_image2)
labels2 = db.labels_
plt.figure(2)
plt.subplot(2, 1, 1)
plt.imshow(img)
plt.axis('off')
# plt.subplot(2, 1, 2)
# plt.imshow(np.reshape(labels, [rows, cols]))
# plt.axis('off')
plt.subplot(2, 1, 2)
plt.imshow(np.reshape(labels2, [rows, cols]))
plt.axis('off')
plt.show()

Related

How to split image of table at vertical lines into three images?

I want to split an image of a table at the vertical lines into three images as shown below. Is it possible? The width of each column is variable. And the sad thing is that the left vertical line is drawn down from the header as you can see.
Input image (input.png)
Output image (output1.png)
Output image (output2.png)
Output image (output3.png)
Update 1
And the sad thing is that the left vertical line is drawn down from the header as you can see.
It means I guess the following image B is easier to split. But my case is A.
Update 2
I am trying to do the way #HansHirse gave me. My expectation is sub_image_1.png, sub_image_2.png and sub_image_3.png are stored in the out folder. But no luck so far. I'm looking into it.
https://github.com/zono/ocr/blob/16fd0ec9a2c7d2e26279ec53947fe7fbab9f526d/src/opencv.py
$ git clone https://github.com/zono/ocr.git
$ cd ocr
$ git checkout 16fd0ec9a2c7d2e26279ec53947fe7fbab9f526d
$ docker-compose up -d
$ docker exec -it ocr /bin/bash
$ python3 opencv.py
Since your table is perfectly aligned, you can inverse binary threshold your image, and count (white) pixels along the y-axis to detect the vertical lines:
You'll need to clean the peaks, since you might get plateaus for the thicker lines.
That'd be my idea in Python OpenCV:
import cv2
import numpy as np
from skimage import io # Only needed for web reading images
# Web read image via scikit-image; convert to OpenCV's BGR color ordering
img = cv2.cvtColor(io.imread('https://i.stack.imgur.com/BTqBs.png'), cv2.COLOR_RGB2BGR)
# Inverse binary threshold grayscale version of image
img_thr = cv2.threshold(cv2.cvtColor(img, cv2.COLOR_BGR2GRAY), 128, 255, cv2.THRESH_BINARY_INV)[1]
# Count pixels along the y-axis, find peaks
thr_y = 200
y_sum = np.count_nonzero(img_thr, axis=0)
peaks = np.where(y_sum > thr_y)[0]
# Clean peaks
thr_x = 50
temp = np.diff(peaks).squeeze()
idx = np.where(temp > thr_x)[0]
peaks = np.concatenate(([0], peaks[idx+1]), axis=0) + 1
# Save sub-images
for i in np.arange(peaks.shape[0] - 1):
cv2.imwrite('sub_image_' + str(i) + '.png', img[:, peaks[i]:peaks[i+1]])
I get the following three images:
As you can see, you might want to modify the selection by +/- 1 pixel, if an actual line is only 1 pixel wide.
Hope that helps!
----------------------------------------
System information
----------------------------------------
Platform: Windows-10-10.0.16299-SP0
Python: 3.8.1
NumPy: 1.18.1
OpenCV: 4.2.0
----------------------------------------
OpenCV has a line detection function:
You can filter the lines that are returned by passing min_theta and max_theta. For vertical lines you can specify maybe : 88 and 92 respectively for margin.
This is a edited sample taken from openCV documentation:
import sys
import math
import cv2 as cv
import numpy as np
def main(argv):
default_file = 'img.png'
filename = argv[0] if len(argv) > 0 else default_file
# Loads an image
src = cv.imread(cv.samples.findFile(filename), cv.IMREAD_GRAYSCALE)
#some preparation of the photo
dst = cv.Canny(src, 50, 200, None, 3)
# Copy edges to the images that will display the results in BGR
cdst = cv.cvtColor(dst, cv.COLOR_GRAY2BGR)
cdstP = np.copy(cdst)
lines = cv.HoughLines(dst, 1, np.pi / 180, 150, None, 88, 92) #min and max theta
You can get the x, y coordinate of the line and draw them by using the following code.
if lines is not None:
for i in range(0, len(lines)):
rho = lines[i][0][0]
theta = lines[i][0][2]
a = math.cos(theta)
b = math.sin(theta)
x0 = a * rho
y0 = b * rho
pt1 = (int(x0 + 1000*(-b)), int(y0 + 1000*(a)))
pt2 = (int(x0 - 1000*(-b)), int(y0 - 1000*(a)))
cv.line(cdst, pt1, pt2, (0,0,255), 3, cv.LINE_AA)
Alternatively you can also use HoughLinesP as this allows you to specify a minimum length, which will help your filtering. Also the lines are returned as x,y pairs for each end making it easier to work with.
linesP = cv.HoughLinesP(dst, 1, np.pi / 180, 50, None, 50, 10)
if linesP is not None:
for i in range(0, len(linesP)):
l = linesP[i][0]
cv.line(cdstP, (l[0], l[2]), (l[2], l[3]), (0,0,255), 3, cv.LINE_AA)
cv.imshow("Source", src)
cv.imshow("Detected Lines (in red) - Standard Hough Line Transform", cdst)
cv.imshow("Detected Lines (in red) - Probabilistic Line Transform", cdstP)
cv.waitKey()
return 0
Documentation
To crop your image you can take the x coordinates of the lines you detected and use numpy slicing.
for i in range(0, len(linesP) - 1):
l = linesP[i][0]
xcoords = l[0], linesP[i+1][0][0]
slice = img[:xcoords[0],xcoords[1]]
cv.imshow('slice', slice)
cv.waitKey(0)

Layer concatenation with Keras

I'm planning to have the following design:
However my code doesn't seem working:
import numpy as np
from keras.models import Model
from keras.layers import Dense, Input, Concatenate
from keras import optimizers
trainX1 = np.array([[1,2],[3,4],[5,6],[7,8]]) # fake training data
trainY1 = np.array([[1],[2],[3],[4]]) # fake label
trainX2 = np.array([[2,3],[4,5],[6,7]])
trainY2 = np.array([[1],[2],[3]])
trainX3 = np.array([[0,1],[2,3]])
trainY3 = np.array([[1],[2]])
numFeatures = 2
trainXList = [trainX1, trainX2, trainX3]
trainYStack = np.vstack((trainY1,trainY2,trainY3))
inputList = []
modelList = []
for i,_ in enumerate(trainXList):
tempInput= Input(shape = (numFeatures,))
m = Dense(10, activation='tanh')(tempInput)
inputList.append(tempInput)
modelList.append(m)
mAll = Concatenate()(modelList)
out = Dense(1, activation='tanh')(mAll)
model = Model(inputs=inputList, outputs=out)
rmsp = optimizers.rmsprop(lr=0.00001)
model.compile(optimizer=rmsp,loss='mse', dropout = 0.1)
model.fit(trainXList, trainYStack, epochs = 1, verbose=0)
The error message says that my input data sets are not having the same shape, but after I padded my training set to make number of samples = 4 for all 3 sets, I still get errors saying dimension is not right. May I know how I can design this network properly? Thanks!
p.s. Here is the error message before padding:
ValueError: All input arrays (x) should have the same number of samples. Got array shapes: [(4, 2), (3, 2), (2, 2)]
Here is the error message after padding (happens on the last line of code):
ValueError: Input arrays should have the same number of samples as target arrays. Found 4 input samples and 12 target samples.
Your input shape is wrong for the given input.
You assign the input a size of numFeatures, but actually you have 2-dimensional arrays and they are different (4,2)(3,2)(2,2). I am not sure about your problem, but number of samples and number of features seem to be reversed.
tempInput= Input(shape = (numFeatures,))
Furthermore your y is also weird. Usually you have X (number_of samples, num_features) and y with (number of samples, labels).
Use model.summary() to see how your network looks like.

MXNet - application of GANs to MNIST

So this question is about GANs.
I am trying to do a trivial example for my own proof of concept; namely, generate images of hand written digits (MNIST). While most will approach this via deep convolutional gans (dgGANs), I am just trying to achieve this via the 1D array (i.e. instead of 28x28 gray-scale pixel values, a 28*28 1d array).
This git repo features a "vanilla" gans which treats the MNIST dataset as a 1d array of 784 values. Their output values look pretty acceptable so I wanted to do something similar.
Import statements
from __future__ import print_function
import matplotlib as mpl
from matplotlib import pyplot as plt
import mxnet as mx
from mxnet import nd, gluon, autograd
from mxnet.gluon import nn, utils
import numpy as np
import os
from math import floor
from random import random
import time
from datetime import datetime
import logging
ctx = mx.gpu()
np.random.seed(3)
Hyper parameters
batch_size = 100
epochs = 100
generator_learning_rate = 0.001
discriminator_learning_rate = 0.001
beta1 = 0.5
latent_z_size = 100
Load data
mnist = mx.test_utils.get_mnist()
# convert imgs to arrays
flattened_training_data = mnist["test_data"].reshape(10000, 28*28)
define models
G = nn.Sequential()
with G.name_scope():
G.add(nn.Dense(300, activation="relu"))
G.add(nn.Dense(28 * 28, activation="tanh"))
D = nn.Sequential()
with D.name_scope():
D.add(nn.Dense(128, activation="relu"))
D.add(nn.Dense(64, activation="relu"))
D.add(nn.Dense(32, activation="relu"))
D.add(nn.Dense(2, activation="tanh"))
loss = gluon.loss.SoftmaxCrossEntropyLoss()
init stuff
G.initialize(mx.init.Normal(0.02), ctx=ctx)
D.initialize(mx.init.Normal(0.02), ctx=ctx)
trainer_G = gluon.Trainer(G.collect_params(), 'adam', {"learning_rate": generator_learning_rate, "beta1": beta1})
trainer_D = gluon.Trainer(D.collect_params(), 'adam', {"learning_rate": discriminator_learning_rate, "beta1": beta1})
metric = mx.metric.Accuracy()
dynamic plot (for juptyer notebook)
import matplotlib.pyplot as plt
import time
def dynamic_line_plt(ax, y_data, colors=['r', 'b', 'g'], labels=['Line1', 'Line2', 'Line3']):
x_data = []
y_max = 0
y_min = 0
x_min = 0
x_max = 0
for y in y_data:
x_data.append(list(range(len(y))))
if max(y) > y_max:
y_max = max(y)
if min(y) < y_min:
y_min = min(y)
if len(y) > x_max:
x_max = len(y)
ax.set_ylim(y_min, y_max)
ax.set_xlim(x_min, x_max)
if ax.lines:
for i, line in enumerate(ax.lines):
line.set_xdata(x_data[i])
line.set_ydata(y_data[i])
else:
for i in range(len(y_data)):
l = ax.plot(x_data[i], y_data[i], colors[i], label=labels[i])
ax.legend()
fig.canvas.draw()
train
stamp = datetime.now().strftime('%Y_%m_%d-%H_%M')
logging.basicConfig(level=logging.DEBUG)
# arrays to store data for plotting
loss_D = nd.array([0], ctx=ctx)
loss_G = nd.array([0], ctx=ctx)
acc_d = nd.array([0], ctx=ctx)
labels = ['Discriminator Loss', 'Generator Loss', 'Discriminator Acc.']
%matplotlib notebook
fig, ax = plt.subplots(1, 1)
ax.set_xlabel('Time')
ax.set_ylabel('Loss')
dynamic_line_plt(ax, [loss_D.asnumpy(), loss_G.asnumpy(), acc_d.asnumpy()], labels=labels)
for epoch in range(epochs):
tic = time.time()
data_iter.reset()
for i, batch in enumerate(data_iter):
####################################
# Update Disriminator: maximize log(D(x)) + log(1-D(G(z)))
####################################
# extract batch of real data
data = batch.data[0].as_in_context(ctx)
# add noise
# Produce our noisey input to the generator
latent_z = mx.nd.random_normal(0,1,shape=(batch_size, latent_z_size), ctx=ctx)
# soft and noisy labels
# real_label = mx.nd.ones((batch_size, ), ctx=ctx) * nd.random_uniform(.7, 1.2, shape=(1)).asscalar()
# fake_label = mx.nd.ones((batch_size, ), ctx=ctx) * nd.random_uniform(0, .3, shape=(1)).asscalar()
# real_label = nd.random_uniform(.7, 1.2, shape=(batch_size), ctx=ctx)
# fake_label = nd.random_uniform(0, .3, shape=(batch_size), ctx=ctx)
real_label = mx.nd.ones((batch_size, ), ctx=ctx)
fake_label = mx.nd.zeros((batch_size, ), ctx=ctx)
with autograd.record():
# train with real data
real_output = D(data)
errD_real = loss(real_output, real_label)
# train with fake data
fake = G(latent_z)
fake_output = D(fake.detach())
errD_fake = loss(fake_output, fake_label)
errD = errD_real + errD_fake
errD.backward()
trainer_D.step(batch_size)
metric.update([real_label, ], [real_output,])
metric.update([fake_label, ], [fake_output,])
####################################
# Update Generator: maximize log(D(G(z)))
####################################
with autograd.record():
output = D(fake)
errG = loss(output, real_label)
errG.backward()
trainer_G.step(batch_size)
####
# Plot Loss
####
# append new data to arrays
loss_D = nd.concat(loss_D, nd.mean(errD), dim=0)
loss_G = nd.concat(loss_G, nd.mean(errG), dim=0)
name, acc = metric.get()
acc_d = nd.concat(acc_d, nd.array([acc], ctx=ctx), dim=0)
# plot array
dynamic_line_plt(ax, [loss_D.asnumpy(), loss_G.asnumpy(), acc_d.asnumpy()], labels=labels)
name, acc = metric.get()
metric.reset()
logging.info('Binary training acc at epoch %d: %s=%f' % (epoch, name, acc))
logging.info('time: %f' % (time.time() - tic))
output
img = G(mx.nd.random_normal(0,1,shape=(100, latent_z_size), ctx=ctx))[0].reshape((28, 28))
plt.imshow(img.asnumpy(),cmap='gray')
plt.show()
Now this doesn't get nearly as good as the repo's example from above. Although fairly similar.
Thus I was wondering if you could take a look and figure out why:
the colors are inverted
why the results are sub par
I have been fiddling around with this trying a lot of various things to improve the results (I will list this in a second), but for the MNIST dataset this really shouldn't be needed.
Things I have tried (and I have also tried a host of combinations):
increasing the generator network
increasing the discriminator network
using soft labeling
using noisy labeling
batch norm after every layer in the generator
batch norm of the data
normalizing all values between -1 and 1
leaky relus in the generator
drop out layers in the generator
increased learning rate of discriminator compared to generator
decreased learning rate of i compared to generator
Please let me know if you have any ideas.
1) If you look into original dataset:
training_set = mnist["train_data"].reshape(60000, 28, 28)
plt.imshow(training_set[10,:,:], cmap='gray')
you will notice that the digits are white on a black background. So, technically speaking, your results are not inversed - they match the pattern of original images you used as a real data.
If you want to invert colors for visualization purposes, you can easily do that by changing the pallete to reversed one by adding '_r' (it works for all color palletes):
plt.imshow(img.asnumpy(), cmap='gray_r')
You also can play with ranges of colors by changing vmin and vmax parameters. They control how big the difference between colors should be. By default it is calculated automatically based on provided set.
2) "Why the results are sub par" - I think this is exactly the reason why the community started to use dcGANs. To me the results in the git repo you provided are quite noisy. Surely, they are different from what you receive, and you can achieve the same quality just by changing your activation functions from tanh to sigmoid as in the example on github:
G = nn.Sequential()
with G.name_scope():
G.add(nn.Dense(300, activation="relu"))
G.add(nn.Dense(28 * 28, activation="sigmoid"))
D = nn.Sequential()
with D.name_scope():
D.add(nn.Dense(128, activation="relu"))
D.add(nn.Dense(64, activation="relu"))
D.add(nn.Dense(32, activation="relu"))
D.add(nn.Dense(2, activation="sigmoid"))
Sigmoid never goes below zero and it works better in this scenario. Here is a sample picture I get if I train updated model for 30 epochs (the rest of the hyperparameters are same).
If you decide to explore dcGAN to get even better results, take a look here - https://mxnet.incubator.apache.org/tutorials/unsupervised_learning/gan.html It is a well explained tutorial on how to build dcGAN with Mxnet and Gluon. By using dcGAN you will get way better results than that.

unsupervised learning how to get number of clusters

In this code below the author says that -
"Before I begin the kmeans clustering I want to use a hierarchial clustering to figure how many clusters I should have. I truncated the dendrogram because if I didn't the dendrogram will be hard to read. I cut at 20 because it has the second biggest distance jump (the first big jump is at 60). After the cut there are 7 clusters."
I am not able to see in the Dendrogram how he arrived at the numbers he mentioned - 20, 60 or 7
I am attaching the dendrogram that I have got from the sample data taken from his github example and am wondering if anyone can shed light on how he arrived at the numbers 20, 60 or 7
he also says "Let's fit k-means on the matrix with a range of clusters 1 - 19." where did he get that range 1 to 19 from? is it cause of the drop at 20 (or the cut off at 20)
github - https://github.com/moyphilip/SKU-Clustering
Also what would one say should be the number of clusters in this second image attached here ? 6 clusters ? (its a different dataset)
from sklearn.feature_extraction.text import TfidfVectorizer
import os
import pandas as pd
import re
import numpy as np
df = pd.read_csv('sample-data.csv')
def split_description(string):
string_split = string.split(' - ',1)
name = string_split[0]
return name
df_new = pd.DataFrame()
df_new['name'] = df.loc[:,'description'].apply(lambda x: split_description(x))
df_new['id'] = df['id']
def remove(name):
new_name = re.sub("[0-9]", '', name)
new_name = ' '.join(new_name.split())
return new_name
df_new['name'] = df_new.loc[:,'name'].apply(lambda x: remove(x))
df_new.head()
tfidf_vectorizer = TfidfVectorizer(
use_idf=True,
stop_words = 'english',
ngram_range=(1,4), min_df = 0.01, max_df = 0.8)
tfidf_matrix = tfidf_vectorizer.fit_transform(df_new['name'])
print (tfidf_matrix.shape)
print (tfidf_vectorizer.get_feature_names())
from sklearn.metrics.pairwise import cosine_similarity
dist = 1.0 - cosine_similarity(tfidf_matrix)
print (dist)
from scipy.cluster.hierarchy import ward, dendrogram
#run_line_magic('matplotlib', 'inline')
import matplotlib.pyplot as plt
linkage_matrix = ward(dist) #define the linkage_matrix using ward clustering pre-computed distances
fig, ax = plt.subplots(figsize=(15, 20)) # set size
ax = dendrogram(linkage_matrix,
truncate_mode='lastp', # show only the last p merged clusters
p=20, # show only the last p merged clusters
leaf_rotation=90.,
leaf_font_size=12.,
labels=list(df_new['name']))
plt.axhline(y=20, linewidth = 2, color = 'black')
fig.suptitle("Hierarchial Clustering Dendrogram Truncated", fontsize = 35, fontweight = 'bold')
#fig.show()
from sklearn.cluster import KMeans
num_clusters = range(1,20)
KM = [KMeans(n_clusters=k, random_state = 1).fit(tfidf_matrix) for k in num_clusters]
# Let's plot the within cluster sum of squares for each k to see which k I should choose.
#
# The plot shows a steady decline from from 0 to 19. Since the elbow rule does not apply for this I will choose k = 7 because of the previous dendrogram.
# In[17]:
import matplotlib.pyplot as plt
#get_ipython().run_line_magic('matplotlib', 'inline')
with_in_cluster = [KM[k].inertia_ for k in range(0,len(num_clusters))]
plt.plot(num_clusters, with_in_cluster)
plt.ylim(min(with_in_cluster)-1000, max(with_in_cluster)+1000)
plt.ylabel('with-in cluster sum of squares')
plt.xlabel('# of clusters')
plt.title('kmeans within ss for k value')
plt.show()
# I add the cluster label to each record in df_new
# In[18]:
model = KM[6]
clusters = model.labels_.tolist()
df_new['cluster'] = clusters
# Here is the distribution of clusters. Cluster 0 has a records, then cluster 1. Cluster 2 - 4 seem pretty even.
# In[19]:
df_new['cluster'].value_counts()
# I print the top terms per cluster and the names in the respective cluster.
# In[20]:
print("Top terms per cluster:")
print
order_centroids = model.cluster_centers_.argsort()[:, ::-1]
terms = tfidf_vectorizer.get_feature_names()
for i in range(model.n_clusters):
print ("Cluster %d : " %i )
for ind in order_centroids[i, :10]:
print ( '%s' % terms[ind])
print
print ("Cluster %d names:" %i)
for idx in df_new[df_new['cluster'] == i]['name'].sample(n = 10):
print ( ' %s' %idx)
print
print
# I reduce the dist to 2 dimensions with MDS. The dissimilarity is precomputed because we provide 1 - cosine similarity. Then I assign the x and y variables.
# In[21]:
import matplotlib.pyplot as plt
import matplotlib as mpl
from sklearn.manifold import MDS
mds = MDS(n_components=2, dissimilarity="precomputed", random_state=1)
pos = mds.fit_transform(dist)
xs, ys = pos[:, 0], pos[:, 1]
# In[22]:
cluster_colors = {0: '#85C1E9', 1: '#FF0000', 2: '#800000', 3: '#04B320',
4: '#6033FF', 5: '#33FF49', 6: '#F9E79F', 7: '#935116',
8: '#9B59B6', 9: '#95A5A6'}
cluster_labels = {0: 'vest dress print', 1: 'shirt merino island',
2: 'pants guide pants guide', 3: 'shorts board board shorts',
4: 'simply live live simply', 5: 'cap cap bottoms bottoms',
6: 'jkt zip jkt guide'}
#some ipython magic to show the matplotlib plots inline
#get_ipython().run_line_magic('matplotlib', 'inline')
#create data frame that has the result of the MDS plus the cluster numbers and titles
df_plot = pd.DataFrame(dict(x=xs, y=ys, label=clusters, name=df_new['name']))
#group by cluster
groups = df_plot.groupby('label')
# set up plot
fig, ax = plt.subplots(figsize=(17, 9)) # set size
for name, group in groups:
ax.plot(group.x, group.y, marker='o', linestyle='', ms=12,
label = cluster_labels[name],
color = cluster_colors[name])
ax.set_aspect('auto')
ax.legend(numpoints = 1)
fig.suptitle("SKU Clustering", fontsize = 35, fontweight = 'bold')
#plt.show()

Why am I getting only one channeled-output through the tf.nn.conv2d?

import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt
from scipy.misc import imread
img = imread('dog2.jpg')
#img is a shape of (360, 480, 3)
w = img.shape[0]
h = img.shape[1]
c = img.shape[2]
k = 3 # for my convenience
plt.subplot(1,2,1)
plt.imshow(img)
img = tf.cast(img, tf.float32)
img4d = tf.reshape(img,[1,w,h,c])
diag = np.array([[1,1,1],[0,0,0],[1,1,1]]*k, np.float32)
# diag = np.diag(diag)
diag4d = tf.reshape(diag,[k,k,c,1])
convolved = tf.nn.conv2d(img4d, diag4d, strides=[1,1,1,1], padding='SAME')
with tf.Session() as sess:
result = sess.run(convolved)
print result.shape
plt.subplot(1,2,2)
plt.imshow(np.squeeze(result))
plt.show()
I am just trying to use convolution and apply some blur effect initially. Yeah I know that my kernel values aren't right. But my question is, I am giving an input image that has 3 channels. How could I get an output image of 3 channels. Well. I tried. But all I get is some one channeled values alone.
You are passing a kernel of shape [3, 3, 3, 1] to tf.nn.conv2d(). If you want to get a 3-channel image output from your convolution, the fourth dimension of your kernel (called out_channels in the official documentation) should be 3 instead of 1; [3, 3, 3, 3] for example.
You could also take a look at the conv2d documentation, this question and this question to better understand Tensorflow's conv2d method.

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