Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [image]

This tag is for questions related to the loading, formatting, saving, compression, and display of data representing pictures.

9
votes
0answers
155 views

Multithreaded Groovy Mandelbrot

Seeing as it's October, I thought I'd do the community challenge. Due to my inexperience coding in Groovy, I decided to give Groovy a go. I'm not sure how well I followed Groovy conventions, and the ...
7
votes
0answers
584 views

Read quantization tables from JPEG files

I'm developing an application that will hide information inside the quantization tables of JPEG files. It's called DQTsteg, if you want to know more about what I'm attempting to do. Right now I'm ...
6
votes
0answers
127 views

Python class for organizing images for machine learning

I built a class to help me handle image data to use in machine learning. I thought that there would be a pre-existing package that did what I wanted but I couldn't find it so I wrote this. I am not ...
6
votes
0answers
244 views

Simple AR Tag classifier

I have been working on creating a simple AR Tag classifier, for detecting a simple AR Tag glyph. Spitting out an image that looks like this: With the red circle indicating the corner closest to the ...
6
votes
0answers
1k views

Iterate through all the photo library in iOS

This function is supposed to return a map of all unique local identifiers of images that are on the iPhone using the IOS Photos Framework. (it is a map so nSnull or (any object can be mapped to it) ...
4
votes
0answers
44 views

Functional blob counting

I have image files consisting of black and white pixels encoded as RGB8. I want to count the number of blobs i.e. contiguous areas of white pixels. I rewrote this algorithm in haskell. The algorithm ...
4
votes
0answers
57 views

Drawing the Mandelbrot with multiple threads in rust

The code below draws the mandelbrot set for { z | z∈ ℂ, -2.2 ≤ Re(z) ≤ 0.6, -1.4 ≤ Im(z) ≤ 1.4} into a 300×300px png image. For each pixel, if the sequence {zi} is found to ...
4
votes
0answers
2k views

Capture, display, and save webcam video with openCV using C++

The basics were taken from one of the more basic OpenCV examples. Any comments are welcome regarding style and conventions, etc., as well as tips on using the OpenCV library, which I'm new to. Also, ...
4
votes
0answers
51 views

Basic declarative style to rotate and crop an image array

I wrote a couple of basic Clojure functions (practicing a declarative style) and I was looking to get some feedback on them. You can see all the code here. Is there anything I could improve on to ...
4
votes
0answers
137 views

Super Resolution in the Wolfram Language, Attempt 2

This is a wolfram language program I wrote for super-resolution, in this case meaning to guess at how to increase the the resolution, and so detail shown in a raster image such as a photograph. It ...
4
votes
0answers
94 views

Optimizing image generation in Perlin noise generator

I've created a simple Perlin noise generator in JavaScript and am trying to find ways to optimize it. It lives inside a webpage and generates an image using nothing more than random number generator ...
3
votes
0answers
36 views

Export EXIF data from thousands of images to CSV

I have written a script that retrieves specific fields of Exif data from thousands of images in a directory (including subdirectories) and saves the info to a csv file: ...
3
votes
0answers
388 views

Distance transform on image using NumPy

I would like to find the find the distance transform of a binary image in the fastest way possible without using the scipy function distance_transform_edt(). The ...
3
votes
0answers
50 views

Image Manipulation with PIL/Pillow - Picture effect/filter

I was curious about image manipulation and I was wondering how it was working, so I made some little functions wich are modifying the pictures passed in parameter. The graphics results are not too bad,...
3
votes
0answers
79 views

Searching for the location of a sub-image within an image

I have a number of images that were cropped and their backgrounds removed. I've tried to write a function that will search the original unmodified image for the cropped image so that I can restore the ...
3
votes
0answers
55 views

Numpy versus Theano GPU parallelization

I am learning Theano to accelerate my image processing functions. As a start, I am trying to reimplement the function to turn images from colors to black and white (with the same number of channels): ...
3
votes
0answers
299 views

PCA, LDA and Logistic Regression

Based on the great blog by Joel Grus, I implemented LogisticRegression, PCA, and LDA. I'd appreciate feedback as I'm not sure that the logistic classifier is good enough (as it supposed to achieve ...
3
votes
0answers
45 views

Getting hex colours from a image

I am trying to get the hex colours from an image. The problem I am having for some reason randomly the code causes high CPU usage, which times out the browser and I am not sure how to optimise the ...
3
votes
0answers
61 views

Remove pre-loader animations when all assets on page become available

This code starts when the page loads and when all assets become available, it removes pre-loader animation and page becomes visible. I know some functions has code repetition, but it can await ...
3
votes
0answers
1k views

Optimization of YUV422 to RGB

I have a stream of YUV422 encoded images coming in from a camera using Direct Show. I then run this byte array through a conversion method and return the RGB array to C# to display in a WPF app. My ...
3
votes
0answers
44 views

Image placement & animation from grid

I have a grid of different sized images. I made a click event function that grabs the image inside any clicked grid-item. It then saves the coordinates and size of the image and animates from the grid ...
3
votes
0answers
38 views
3
votes
0answers
758 views

React Image component that loads and blurs an image onto a canvas

My react.js Image component will load an image from a URL or base64 string, do some processing on it and put it on a canvas. The "preload" prop is a 10x10 pixel image that is blurred just a little bit ...
3
votes
0answers
44 views

Simple gallery with scroll

I just created a simple gallery with scroll. Everything works fine but I'm not sure how should I optimize this code: ...
3
votes
0answers
1k views

Serving images from a Raspberry Pi camera over HTTP

I have a Pi with a camera module that I control with Python. I created a web server with web.py that allows me to make HTTP requests to the PI to retrieve an image. There are two optional parameters ...
3
votes
0answers
71 views

A version of the Pebble Big Time watch face that also displays the date

I'm seeking style pointers, bugs, memory leaks, incorrect usage etc. ...
3
votes
0answers
429 views

Algorithm for downloading images

I am working on a product application where user could sell/buy. This application is based on collection view. Collection view has collection cell where it displays product image thumbnail. The ...
3
votes
0answers
546 views

Grayscale bilinear patch extraction - SSE optimization

My program makes an intensive use of small sub-images extracted using bilinear interpolation from larger grayscale images (some call this problem subpixel translation). I am using the following C++ ...
3
votes
0answers
80 views

Does this go raytracing program follow best practices, and typical project layout?

I'm working through learning Go, so as an exercise, I'm writing a simple raytracer. I'd like general feedback on the code style & architecture. Specific areas of concern: Is the project layout ...
3
votes
0answers
216 views

Getting colors from an image PHP

I am working on a site that themes itself based on images / logos. I have built the class that gets the colors from an image, shown below. I am fairly new to OOP with PHP, and I'm looking for feedback ...
2
votes
0answers
61 views

LSB Image Steganography

After learning the concept of steganography, I've decided to code an application for it in PHP out of all languages, using the Least Significant Bit technique. A pixel of a colored image generally ...
2
votes
0answers
41 views

Extracting face features from selfies faster

My code takes two .jpg files (two selfies) and extracts a vector of 128 features from each selfie. After this extraction we take these two vectors and get their cosine distance. I timed the script ...
2
votes
0answers
147 views

Design pattern: image downloads

This is an image representation of my code below: This is what they do: CellWithImageX: Subclasses of UITableViewCell. They have an image and an loading indicator....
2
votes
0answers
28 views

Calculate average round cell value from each 2D array cell

I am try to practice the leetcode and hit the following question 'image smooth'. Basically the question is to calculate average the around cell value from a 2D array. I have following code. But if ...
2
votes
0answers
441 views

Gray-level co-occurrence matrix feature computation

I have many images and want to compute the GLCM properties for every image. Below my code that runs many hours to complete the task: ...
2
votes
0answers
873 views

PyQt5 - Open new image window for each button click in menu

I wanted to write a code that each time I will press some button in my menu, a numpy image array will somehow be created, and this image will show up in a new window. So the following code is the ...
2
votes
0answers
48 views

Iterate through images really fast with JS

My objective is to modify the JavaScript code to get the single image on the page to iterate through images faster. It should be possible to get the images to load in about 10 seconds(about 3 seconds ...
2
votes
0answers
37 views

Image slider code

I've been doing this image slider section, I've been working on this code for quite a time, the code is perfectly working but I want to improve it. I tried for hours and couldn't find a way. Maybe ...
2
votes
0answers
59 views

Javascript drawing image with genetic algorithm

I first posted this question on stackoverflow and have been indicated that cordereview would be a better place for my question. I have had very good suggestions, such as using RMS for the fitness ...
2
votes
0answers
33 views

Write 16x16 bitmap to frame buffer

The following code writes a 16x16 bitmap to a framebuffer using up to AVX2 instuctions. I'm sure it can be improved with AVX512 ...
2
votes
0answers
56 views

App showing a welcome page with an animal's picture

I have an app which shows a welcome page with an animal's picture. Also, we can navigate to a second view, where there are two canvas, and a collapsable panel which hosts controls' inputs. The aim of ...
2
votes
0answers
603 views

Optimize GPU usage for real-time object detection from camera with TensorFlow GPU and OpenCV

Trying to recognize objects real time using TensorFlow Object Detection API OpenCV using ssd_mobilenet_v1_coco_11_06_2017 model in GPU. ...
2
votes
0answers
44 views

Ensuring images will look as best as possible on any size using object-fit and a container class

This is a snippet from my codebase. Here's how I write markup for my images. In order to make sure that, no matter the specs of the image, it will look as best as possible most of the time: ...
2
votes
0answers
127 views

Send image between apps

I have an ASP.NET CORE API app and now I have an endpoint like: ...
2
votes
0answers
201 views

Computing the weighted centroid dependent on previous row/column

I am working on a project for a Raspberry Pi that requires some image processing. The aim is to find a white line on a black background by finding the weighted mean in each row/column. However to ...
2
votes
0answers
103 views

MPI BMP image comparison

I made a simple program in which I compare two images pixel by pixel and determine if the pictures are the same. I'm trying to adapt it to MPI, but I'm afraid that the communications are taking too ...
2
votes
0answers
177 views

Transform and transpose byte[] of 32bit image data in 24bit array image data

I would like to know if someone can think about a better solution for doing this stuff. I have an array of raw bitmap data in 32bit format (RGBA). I need to transform and transpose this array into a ...
2
votes
0answers
467 views

Linear interpolation Matlab to C++

I don't have a strong mathematics/Matlab background. I would like to convert this Black level correction function from Matlab to C++. Please comment about on the code style and correctness of my ...
2
votes
0answers
456 views

Bitmap to base64 and writefile

I have the following code which does 2 things: Return a scanned fingerprint as base64 Store this print as bitmap While the code works most of the time, sometimes an invalid bitmap is saved (I can't ...
2
votes
0answers
96 views

Parallelized image transformations using GraphicsMagick

This is part of a script that I use for porting a TWRP theme from one resolution to another, respectively portrait to portrait and landscape to landscape. In this function entirely, it focuses on the ...