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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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How to convert YUV422 (sub sampling) to YUV?

I'm coding a video codec using the JPEG compression technic for each frame. Until here I've already coded YUV, DCT and quantized DCT (encoding and decoding). I already have coded YUV422 encoding too but I don't understand how to do the inverse…
user1364743
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Is it possible to re-encode a BMP made of JPG back to JPG without loss of quality?

Sometimes I save JPG images as uncompressed bitmap (BMP/PNG), to keep the quality when I make changes to the image. I was wondering, is it theoretically possible to re-encode the bitmap back to its original JPG format, without losing any quality,…
Rookie
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Saveable image library with compression?

this may be impossible, or rather, not very popular, but I was wondering how I'd go about creating a data file for images, that would actually compress them? Say I had 200MB total of image files, is there some system I can use to store them in a…
Connor Deckers
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How to read out the properties of the Symbol Dictionary used by the JBIG2 algorithm in my pdf?

I have a PDF that contains a long list numbers, that was compressed using the JBIG2 algorithm. When I look up the the internal file structure of my file I can find, that my pages are being built with two different XObjects: (Pictured is Adobe…
SirHawrk
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Compressing a PDF's images using Python (help replacing images inside a PDF)

My goal is to have a Python script that will take a PDF, extract its images, compress/resize them, and then push this new data to the PDF which will result in a new, smaller PDF. So far I have done everything except replace the image data with the…
Kane
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PNG Compression in .net

I want to compress bitmaps to PNG with different compression levels as these levels are available in JPEG compression in C#. I have 20 to 30 images of different sizes to process in 1 sec. Is there any library to achieve this compression in PNG with…
Ehtsham
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Error while compressing Image using Bitmap.CompressFormat.WEBP_LOSSY. which is added in API 30

I am trying to compress And Decode the Image to base64 string using the following method. It works fine when I use Bitmap.CompressFormat.WEBP as compress format but give out NoSuchFieldError error when this method is used…
Ashir Mehmood
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torch.no_grad() affects on model accuracy

I am getting an error "CUDA out of memory" then i add torch.no_grad() function into my code. Is it affect on my accuracy? for iters in range(args.iterations): with torch.no_grad(): encoded, encoder_h_1, encoder_h_2, encoder_h_3 = encoder( …
Khawar Islam
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How to export PDF from Google Docs without over-compressing graphics in header

For setting up a letterhead style layout in Google Docs, we find it handy to put a logo in the header section. However, when the Google Doc is downloaded as a PDF, the image is over-compressed, making it very lossy and unprofessional. This is a…
bonk
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Kotlin Image Compression Implementation

My old implementation to upload image to Firebase Storage in JPEG format without any compression private fun sendToFirebase() { if (imgUri != null) { val fileRef = storageRef!!.child(username+ ".jpg") .... …
Android
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Compress image up to maximum size(100kb) at NodeJS or React Native

I've researched and tried many libraries to achieve this. The main point of task is compressing images(jpeg or png) up to 100KB regardless its quality or resolution. It's fine how bad the quality and resolution are but the size should not larger…
Roy
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Android Image size after compressed from bitmap is very large than original image load to bitmap

I am now a newbie to android programming. I am very confused when processing with images. I am now trying to load a jpeg image to bitmap and then convert bitmap to byte array and vice versa. I am testing with the first case: load jpeg to bitmap and…
bach Vũ
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How do PNG encoders pick which filter to use?

The PNG specification states that there are five possible filters, which can be chosen individually for each row of the image. It gives some general suggestion first: Indexed color and < 8-bit color images should use no filter Truecolor and…
JeffThompson
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Angular 8 - Resizing image on the front-end change-detection issue

I am trying to build an image compressor service from a couple of tutorials I found online . The service itself works as expected , it receives an image as File , then it compresses it and returns an Observable . All works great , except that I want…
Mihaylov
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Image Compression in C#.Net

I am working on creating an Image Manipulation library using C# with MVC3. There is an option where users would be uploading multiple files. These files need to be compressed during transfer to server in order to cut down the upload time and…
Anil C
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