I have user gallery at remote areas where internet speed is limited. And, they can upload multiple documents when asked.
In that case, when I am not suppressing the document image.. it takes time to upload the document and on the other hand, when I do, document loose readability.
So, here, I am finding the way to upload multiple documents with full resolution but without losing quality.
And, document image can be in any format jpg, jpeg, png etc.
Thanks in advance for your help.
I check this Image upload without loss of quality but didn't help it.
The link is .NET, you need Swift, right?
You have a image named "originalImage". The code below compress this image and create a new, smaller one with same resolution. The value (0.8) is compression level.
Upload "compressedImage" to server.
let compressedImage = UIImageJPEGRepresentation(originalImage, 0.8)
Related
I have images that I wanna show it on the web. The extension of the image is .JPG. If you open the file in notepad it starts with LTRI. But that page is not working on browser (even not working on Photos/Paint app of windows 10). It only works on VB6 LeadTools. How can I convert this image? File metadata is below,
You'll need to use the LeadTools libraries. You'll need to register to their site.
I haven't seen anyone else supporting that format, that is proprietary (as written by #Selvin).
Then the code should be easy:
using (RasterCodecs codecs = new RasterCodecs())
{
var image = codecs.Load("yourimage.ext");
// 0 should means "whatever bit format is appropriate"
codecs.Save(image, "out.jpg", Leadtools.RasterImageFormat.Jpeg, 0);
}
The answer posted by xanatos is correct. This appears to be a 1-bit LEAD CMP image file.
We would like to add the following details:
If the images are indeed 1-bit CMP, they would be pure black-and-white, and they would be lossless (unlike color CMP and common JPEG, which are usually lossy formats).
Naming the file aa.JPG is incorrect, since the recommended extension for LEAD images is “.CMP”. However, when using our SDK, the correct format is detected regardless of the file name or its extension.
Converting 1-bit images to JPEG is not recommended, since JPEG files are more suited for full-color images. It’s better to save them as PNG, TIFF or other lossless formats. (The LEADTOOLS SDK supports many such formats).
Using lossless compression shouldn’t produce large files since 1-bit images contain a lot less data than full-color images.
When using the free evaluation of our SDK, technical support is free through chat and email, so feel free to contact us with any questions you have.
What is the role of Augmented Images Database?
I am using arcoreimg tool to generate the img database, but why do need to generate it. I know it is a very basic question please provide your guidance
I am new to AR following Google AR SDK, Please help.
The role of the AugmentedImageDatabase is to store a compressed representation of the images you'd like to track. This is used by ARCore to detect images in the real world.
Generating a database at compile time with the arcoreimg tool has several advantages:
Your app no longer needs to bundle the original PNG or JPEG files. Your app would instead include a smaller database file, resulting in a smaller APK size.
Your app no longer needs to decode the original PNG or JPEG files to extract the image's feature points at runtime. This is an operation which takes roughly ~30ms for each image.
please bear with me as I'm not trying to frustrate anyone with inane questions, and I did google search this but I couldn't really find anything recent or helpful.
I am a novice programmer and I am using a classic asp web application. I just enabled the users to upload and download images, but I'm quickly regretting it as it's eating up all of the router bandwidth. I am finding my solution inadequate, so I wanted to start over.
My desire is threefold with this functionality:
Compression. I understand that this is impossible to do BEFORE uploading without some kind of Java/Silverlight/Flash portion of the application to handle uploads, correct? What is the common way most places go about this? Just allow regular file uploads and compress once they are on the server?
Resizing. I want to resize all images before they are uploaded to a reasonable size, instead of just telling users that try and upload huge camera images that they can't upload. I figure I just want to let them upload and have it resize for them before uploading. Does this functionality exist already?
Changing filetype. I want to allow users to upload all image file types but make them .jpg on the server after the upload.
With these three requirements, how hard is it to implement something like this in just pure code and libraries? Would it be better to just use a 3rd party plugin, such as ASPjpeg or ASPupload? Have you encountered something similar, and what was your solution?
Thanks.
Take a look at ASPJpeg and ASPUpload from Persits. We use these components to upload a full size image (can be png even though the library is "ASPJpeg"), resize it to several different sizes we need on our site, then store the resized images on the server in a variety of folders. The ASPUpload component is a little tricky but if you follow their sample code you'll be fine.
I never found a good component for decompressing uploaded zip files and had to write my own, which I've since abandoned. In the end with upload speeds increasing and storage getting so cheap, it started to matter less and less that the files were compressed before being uploaded.
EDIT: Just noticed you mentioned these components in your question. Consider this an endorsement of your idea to use them. :-)
I want do same working like php timthumb do in ror I tried gems but not found result as I want.
Images are taking much time to load.
for example code in php :
Can check what I required on :
http://www.darrenhoyt.com/demo/timthumb/
I want same way in ror?
You can try minimagick gem to compress image size and quality.
For example:
image = MiniMagick::Image.open(YOUR_IMAGE)
image.resize "130x100" ## The thumbnail size
image.write(YOUR_THUMB)
When you upload an imagine you want to have different sized versions that have been processed from the original.
Carrier wave to upload the image and resize it
https://github.com/carrierwaveuploader/carrierwave
You can resize as documented here: Carrier Wave - Versions
To be more precise here are associated tutorials for what you want using carrierwave and various libs for the conversions: Image Dimensions
You can even change the image type to keep a standard and do more image processing with libraries. Here is how: Image Processing
I'm putting together a script to find remove duplicates in a large library of images. At the moment I'm doing a two pass filter of first finding files of the same size and then doing a sha256 on a 10240 byte piece of the file to get a fingerprint of the files with the same size (code here).
It works well, but I'm guessing there are probably checksums built in to the jpeg format that I could use instead of doing the sha256.
Does anyone know if there are checksums or other components that could act as checksums / fingerprints? If so, is there an efficient way to access them?
I don't think the JPEG specification includes any kind of checksum in the way you're describing.
A JPEG can contain a thumbnail as part of its EXIF metadata, though. It's not a perfect indicator, since it's possible for two different images to have the same thumbnail. There's at least one documented case of a thumbnail not being replaced after the image had undergone substantial modifications, said thumbnail revealing much more than the publisher had intended.
Its been awhile since I've dug into the IJG library, but I don't think there's an easy class member or function call you can use there to check for some type of fingerprint. You could use the built in EXIF tags if you can control the encoding of the images...
I'm just built a very similar script. I don't want to checksum metadata I want to see if the actual images are duplicates even if tags have been modified. Best for that is not to sort by size, but do sort by the checksum istelf. I use jhead to remove metadata and then checksum the whole file (but I also thought about just doing part of it, but actually I don't think it saves much time). jhead doesn't use shared memory (pipes) and does overwrite so I just copy the file to shared memory first. I place the checksum in the ImageDescription field for later faster retrieval. Obviously this also allows to check image integrity later and is part of why I checksum the whole thing. Tip: exiv2 is MUCH faster for reading and writing the metadata than exiftool for one at a time decision based manipulation.
In JPEG standard(ITU-T.81) i believe there isn't any field/syntax element which has a checksum or such, for the whole compressed jpeg image file. Unless a customised application puts such filed in the Application segment, or as meta data for which segments are provided in the standard.
So to serve your purpose, what you are doing is one soln.
Other could be some kind a application wrapper which will call some binary file compare utlitiy (like beyond compare, or even a windows command fc /b) and check the result of that compare utility and take the decision u want to.
-AD
One way you could perform is reduce all images to a fixed size and store that as a thumbnail. Then the image comparison would compare similar sized images and give you a chance of being a duplicate - useful if you have cropped (unless cropped heavily) or resized images and want to find those 'duplicates'.
In the XMP specification there are document ID and version ID which should uniquely identify the version of the image.
The problem with these (and with any other metadata-based identification method) is that it might not be respected by some applications that can change the content of the jpeg updating the metadata accordingly.