keypoint detection or 3D reconstruction. Our main contribu-
tions are:
•we extend [2] by adding image scraping and different
image selection methods,
•we analyze the influence of the image selection method
on the capacity for transfer learning,
•we present a real-world dataset of parcel images that is
used for evaluation, and
•we make our code publicly available, to facilitate the
generation of tailored datasets for custom domains.
The paper is organized as follows. We present related
literature in Sec. II. Subsequently, we describe our dataset
generation approach in Sec. III. The evaluation is presented
in Sec. IV and the paper concludes with Sec. V.
II. RELATED WORK
The idea of generating an artificial training dataset is
widespread, due to the high cost that incur for capturing and
annotating a tailor-made dataset for a use-case. We first present
relevant literature regarding the creation of artificial datasets
and subsequently delve into the application area of logistics.
Artificial Dataset Generation: Artificial datasets can ei-
ther be rendered or composed. When rendering images, we can
carefully choose a desired image layout and easily generate
a multiplicity of annotations - even the ones that are very
costly to obtain, such as 3D annotations. BlenderProc [5]
is a procedural Blender1pipeline that enables photorealistic
renderings to create synthetic datasets. Examples for popular
rendered datasets include [6], [7].
In contrast to that, image datasets can also be generated
by composition. Image composition is the task of seamlessly
combining two images by cutting a foreground object from one
image and pasting it onto another image. This is an important
task in computer vision with a wide range of applications.
Niu et al. [8] present a comprehensive survey on the topic,
and we refer to them for details on applications and subtasks
included in image composition. For our work, we focus on
simple image composition and neglect effects that might make
images look unrealistic to humans, as this has proven to be
sufficient for training the backbone of a neural network [9].
More explicitly, inconsistencies introduced by incompatible
colors, unreasonable illumination, mismatching size of objects,
or their location are not considered.
Dwibedi et al. [2] present a procedure to generate a targeted
dataset for instance segmentation. As input, a set of images
for each category, picturing solely the object of interest with a
modest background, is needed. They recommend diverse view-
points, in order to enable detection from diverse viewpoints
as well. A foreground background segmentation network is
trained to obtain segmentation masks for the foreground
objects. In addition, suitable background images need to be
chosen. Afterwards, objects are cut out with their mask from
the images and pasted onto a background image. Dwibedi et
1See https://www.blender.org/.
al. ensure invariance to local artifacts from pasting by applying
a set of blending methods. The exact same images are synthe-
sized multiple times, where only the blending method varies.
They show that this method enables training a neural network
for instance segmentation and that combining the synthetic
data with only 10 % of the real training data surpasses the
performance compared to training on all real data. Ghiasi et
al. [9] present a similar technique, however, they use existing
annotated datasets as their source for both the foreground and
the background and found scale jittering to be very efficient.
First two images within a dataset are randomly chosen and
their scale is jittered. Subsequently, objects from one image
are cut out by using their given annotated mask and pasted ran-
domly onto the second image. During this process annotations
within the second image are adjusted accordingly, i.e. adjusted
for occlusion. They do not use geometric transformations such
as rotation and find Gaussian blurring not to be beneficial.
Ghiasi et al. conclude that their method is highly effective
and robust. Mensink et al. [3] present a study on the influence
of several factors on the performance for transfer learning.
They find that the image domain is the most important factor
and that the target dataset should be contained in the source
dataset to achieve best results.
In our work, we follow an approach similar to Dwibedi et
al. [2], however, fully automate the foreground object image
retrieval by using web scraping and a pre-processing pipeline.
Applications in Logistics.: Work on the plane-wise seg-
mentation of parcels, without the need for a custom training
dataset was presented by Naumann et al. [10]. Plane segmen-
tation information is combined with contour detection to gen-
erate plane-level segmentations. Small load carriers have been
targeted using synthetic training data [11]. Furthermore, the
problem of packaging structure recognition has been tackled
[12]–[14]. Packaging structure recognition aims at localizing
and counting small load carriers that are stacked onto a pallet.
III. DATASET GENERATION
Our dataset generation approach is based on Dwibedi et
al. [2]. We follow a similar procedure, apart from the data
acquisition approach. This section is organized as follows: In
Sec. III-A, we explain the data acquisition through web scrap-
ing. Subsequently, we present three different image selection
methods which yield three different datasets in Sec. III-B. The
image generation is explained in Sec. III-C and finally we
present our real dataset in Sec. III-D.
A. Image Scraping
In order to generate a synthetic dataset, it is crucial to have a
sufficiently large set of images picturing the object of interest.
We approach this problem by scraping images from popular
image search engines. We use four different search engines:
•Google Images: images.google.com,
•Bing Images: bing.com/images,
•Yahoo Images: images.search.yahoo.com and
•Baidu Images: image.baidu.com.