I am currently dealing with very large bitmaps (32bit, > 1GB) close to the bitmap size limit (~ 32 kpx squared). For file storage reasons, I would like to convert these bitmaps into more suitable formats, e.g. jpg or png. But I have to convert them without loading the whole bitmap into memory at once, since I will get a out-of-memory error.
Is there any way how to convert the bitmap in parts, e.g. linewise, blockwise or bandwise? At the moment, I am using Photoshop for saving, but this is not an option at a later stage of the project anymore.
Thanks for the help,
Max
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I'm writing a program that uses Win2D to load an image file and display it on the screen. However, the image file itself is about 5 Mb in size, but when I load it using CanvasBitmap.LoadAsync, the process memory jumps up to over 600MB in memory and then settles down to around 300MB. Is there any way to reduce the process memory without having to resize the image manually in an image editor? I've seen code for resizing other types of bitmaps and I was wondering if that's also possible in Win2D.
Regards,
Alex
Update (1/27/2020)
Realized that bitmaps are uncompressed image files, so the only avalible options are either to reduce the image size somehow, or use a different file format. Decided to use the later because I'm working with PDF files. They can be converted into SVG files using Inkscape. Also, SVG files conveniently happen to be supported by Win2D.
i am converting 8bpp tif file to 8bpp grayscale but it goes larger in file size. i referred
the following url wischik i have tried atalasoft the file size is fine but the some of the files goes negative in irfanview.
can you guys tell me to solve the above both problem(filesize, negative)?
Images size depends on many factors like bpp, compression, colors..etc
Since you have two tiff 8bpp images I believe the most important factor is the compression since both images will contain palettes.
Ideally in your case the two images should be close in size (memory required) when using the same compression but the colored image will most likely be smaller. I have a sdk called leadtools that I use in my development and it gave me the result above.
Also a small note, maybe if you can provide a sample on the image you are facing the problem with we can help you more.
I am trying to resize a pic of format jpg, reduce it's resolution in order for it to be smaller when I download it to the site HTML. Using the tutorial in the link:
image resizing tutorial
I managed to resize the resolution including cropping when needed. My problem is that actual size of the image got bigger instead of smaller as I expected.
Any ideas please?
If a JPEG image file is getting bigger when you are reducing the dimensions, it's because you are saving it with a higher quality setting than the original.
This is quite normal when you use a compressed image format like jpeg. It is caused by the filter you selected when you reduced the image size. A default selection for the Graphics class, for example, is InterpolationMode.Bilinear. Which does a pretty nice job of making a good looking shrunk version of the image. But at a cost of adding a lot of extra colors to the image due to the filtering algorithm. The resulting image won't compress as well as the original and can in fact require more storage.
You'd have to pick a lower quality filter to avoid this, like InterpolationMode.NearestNeighbor. Yes, won't look nearly as good. In general you should avoid re-compressing an image that was already compressed in a lossy format like jpeg.
We have a around 600,000 images that were converted from JPEG to TIFF files and uploaded to our FileNet repository. These TIFF images are multi-page, made by stitching multiple JPEGs.
This was done couple of years ago. Now we started getting complaints from users the quality of the TIFF images are not the same as they were when they were JPEGs.
Is there any way we can improve the quality of TIFF files? If I have to re-migrate this data, can JPEGs be of multiple pages? Please advice.
You can't just add quality to an image, so you can either try improving the appearance of the current information or you'll need to re-create the images to get better information.
To me, it sounds like the initial creation process is the most likely cause of the quality issue. How you create the image is important.
For example, I had a large number of photos I needed to re-size, so I used irfanview's batch convert and the results were horrible. Perhaps I had the settings wrong, I don't know.
I then tried using ImageMagick, and the results were great.
The point being, the conversion process isn't trivial.
If I were you, I'd look at how the images were created, experiment with different settings to determine what gives the best appearance, then re-create your photo gallery.
For photographic material, there's no real reason to use anything other than a jpeg if the target market is the general consumer.
Both TIFF and JPEG support lossless and lossy storage of your images. You mentioned that there was a previous conversion. The conversion was probably a lossy conversion as such you probably won't be able to recover that data to the way it was previously.
That said if you have the original source images you might be able to get back to where you where. Regarding multi-image jpegs, there is such a format *.mpo but I haven't seen it used before so your millage may vary.
You probably converted gray scale or color Jpeg to Tiff. The most common is Tiff G4 which is only 1 bit per pixel. So 24 or 8 bits was converted to 1 bit and you will see a lot of images losses. There are multiple methods to improve image quality but I would have to see the images first to suggest a method.
Goal:
I have lots of pictures in many sizes (both dimensions and file size)
I'd like to convert these files twice:
thumbnail-size pictures
pictures that will look OK on a web page and will be as close to a full screen as possible... and keeping the file size under 500KB.
HTML Questions:
A. What is the best file format to use (jpg, png or other) ?
B. What is the best configuration for web ... as small as possible file size with reasonable quality?
C# Questions
A Is there a good way to achieve this conversion using C# code (if yes, how)?
Try the code in this small C# app for resizing and compressing the graphics. I have reused this code for use in an ASP.NET site without too much work, hopefully you can make use of it. You can run the app to check quality fits your needs etc.
http://blog.bombdefused.com/2010/08/bulk-image-optimizer-in-c-full-source.html
You can pass the image twice, specifying dimensions for a thumbnail, and then again for your display image. It can handle multiple formats (jpg, png, bmp, tiff, gif), and reduce file size significantly without loosing noticeable quality.
On .jpg vs .png, generally jpg is better as you will get a smaller file size than with png. I've generally used this code passing a quality of 90%, which reduces file size significantly, but still looks perfect.
I think PNG is better format for WEB than JPEG that always uses lossy JPG compression, but its degree is selectable, for higher quality and larger files, or lower quality and smaller files. PNG uses ZIP compression which is lossless, and slightly more effective than LZW (slightly smaller files).
In C# you can use System.Drawing namespace types to load, resize and convert mages. This namespace wraps GDI+ API.
A. For graphics I would use png and for fotos jpg.
B. Configuration?
C. There are tons of post that explain that:
http://www.codeproject.com/KB/GDI-plus/imgresizoutperfgdiplus.aspx
Resizing an Image without losing any quality