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Questions tagged [image-compression]

The objective of image compression is to reduce irrelevance and redundancy of the image data in order to be able to store or transmit data in an efficient form. Image compression may be lossy or lossless.

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Considering image compression, is Run length encoding always better than Huffman coding?

We found out that run length is much better than huffman coding (JAVA) considering compression ratio. Is it true for all cases?
sharma
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which Wavelet is used for Jpeg2000 Image Compression?

which Wavelet is used for Jpeg2000 Image Compression ? I was reading the Book on Wavelet Transform to find out how wavelet works for image compression but there are so many types of Wavelets mentioned in the book and i am confused which one is used…
Sufiyan Ghori
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Loading bitmaps into memory in compressed form in Android

I've programmed an Android game in the past and had always run into memory issues because my images have been quite large ~(1000x400 px each). I'm now wondering if it is necessary to load images into memory solely as bitmaps. Is there any reason for…
you786
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Image compression and resize in Java

I need to be able to compress and resize images of type jpeg,gif etc in my Java code. Which library or class in Java should i use for compressing and resizing images ? Thank You
user1276174
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Convert grayscale YUV to an image (2D matrix)

I'm trying to convert a grayscale yuv frame (from a video) to an image. So I extracted the y component, which is a 2D matrix and saved it, but the result was not the image. I guess there should be some kind of transformation in order to get the…
user3265447
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Why do I get matrices of absurd values when trying to reconstruct an image from a singular value decomposition using numpy.linalg?

I am doing a singular value decomposition of a greyscale image (read: big matrix) via numpy.linalg. Thing is, when I try to reconstruct the image from the decomposition I get a matrix of absurd values which cannot correspond to the pixels of the…
Александр Асратян
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Common Compression method for audio,video and images in react-native

I'm using the react-native-compression package for compressing the files, but while using it I'm having an error. and here is the code where I'm adding the Image compressor: I'm getting the file URL while uploading but still it is giving me an…
Karan Rampal
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Ways to reduce image size for wordpress without reducing quality

I am building a WordPress website, and the website runs perfectly, but the images don't load. I've reduced the image sizes from megabytes to kilobytes, but the images still do not load. I used GIMP and www.iloveimg.com and a few other free online…
myt
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Prevent GhostScript to turn PNGs into JPEGs

I use GhostScript to fix/repair non-compliant/corrupted PDFs in order to let them be successfully opened by PDF readers and be edited with Acrobat Pro without errors or warnings. gs \ -o repaired.pdf \ -sDEVICE=pdfwrite \ …
Paolo
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I need to compress the thumb images | PHP

Hello Stackoverflowers, I have successfully been able to compress the main uploaded image, but I don't know how to use the same function to compress the thumbnail. The code main purpose is as follows: 1- Upload an image 2- Rename 3- Compress 4-…
iSafa
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Qt Images in PDF have scaling artifacts

I generate a PDF document directly with a QPrinter (set to HighResolution) where I draw a few pixel images QImage, using QPainter::drawImage(). The images have a very small size (about 200x50 pixels) and have only 3 colors. I zoom them up in the PDF…
Ingmar
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How to compress an image to 200Kb using PHP

In my yii2 project, I have image compression code. I want to compress images of any size to 200kb. I am using Yii2 imagine extension for compressing the image. My code is Image::thumbnail($uploadPath . '/' . $file->name,$newwidth, $newheight) …
Abhijith Abhi
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Compress image before uploading to Firebase

Before I was using MVVM architecture and Kotlin I done it like this in Java. I am passing image Uri to Bitmap Java code: Bitmap actualImage1 = BitmapFactory.decodeStream(getContentResolver().openInputStream(mImageUri)); ByteArrayOutputStream baos =…
Marijan Klarić
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Compressing in Python and decompressing in Java for data transfer

I need to compress PNG images on PC for data transmission in Python, transfer it to mobile and read it there in Java. I need lossless compression. The hard part is compression and decompression in different environments and programming languages. I…
qalis
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Rails lossless image compression in carrierwave

Can we compress image size using carrierwave gem in rails. I just tried "Piet" gem but its giving memory error on heroku server and gem 'carrierwave-imageoptimizer' just do compression for 'jpg' file.
Umer Sani
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