How to compress picture and create File from picture Uri - android

I have Uri of some image at my external storage but it is too large. I have constructor further which accepts only File like parameter. How to make picture smaller adn get File from that ?

Well that depends on how you're displaying the picture. If you're simply going to show that picture in your layout, just size the ImageView element appropriately in your respective layout.xml file:
android:minHeight="your_value"
android:minWidth="your_value"
Also, don't forget to set the adjustViewBounds property as well:
android:adjustViewBounds="true"
If you're looking for something a bit more robust and you're concerned about the memory used to store the entire bitmap for display, then I'd look into using the BitmapFactory class and specifically the inSampleSize field.
This previous question also provides some background for you.

Related

Android how to load Image file with different extension using Picasso

This is a different situation. I want to load a image file which has stored with different extension like 'photo.xyz' instead of 'photo.jpg or photo.png' using Picasso. to avoid image from gallery i am storing image like this. Please help me is there any option to show like this.
Neither Picasso nor Android (which does the actual image decoding) cares what the file name is. It can be anything. The type of the image is always determined from the first few bytes of the actual image data.
As a small workaround you can programmatically put .nomedia file into your app folder to prevent images to be cached by mediaserver and displayed in a Gallery app.

How take photo and reduce image file dimension

in my android app i've implemented a method for taking a photo and save it in a folder specified by me.
I would like to automatically resize the image (or compress it) to reduce the file dimension under the 1MB, obviously before saving it.
Which is the best way to do this?
Thanks
Take a look at this: http://developer.android.com/training/displaying-bitmaps/load-bitmap.html , it has good examples of how to keep your filesize down on photos

how to display images from a selected folder in the form of a slideshow

I am using the following code to pick a folder from the SDCard.
Environment.getExternalStorageDirectory();
After selecting the folder, I return the path of the folder and display it in a text view currently.
What I want to do is, I want to display all images in the selected folder in the form of a slide show. How do I go about in doing this?
1. convert images in the Bitmap.
Bitmap bm = BitmapFactory.decodeFile(String pathName);
Decode a file path into a bitmap.BitmapFactory
2. Using ImageView set that Bitmap in ImageView.
ImageView.setImageBitmap(Bitmap bm);
Sets a Bitmap as the content of this ImageView.
3. For slide show just after some delay (use timer) after change the bitmap of ImageView.
We are appreciate If you are do by yourself. Without finding any code.
EDIT: Here Mihai Fonoage's Blog Displaying Images from SD Card In Android - Part 2 It display images from sdcard in Gridview. You can modified it and display Images one-by-one as a slideshow.
If all you want to do is cycle through the images one by one, there are numerous options. You could for example simply use a Timer (or preferably a ScheduledThreadPoolExecutor if you're writing production code) with a fixed interval or have a Handler repeatedly post itself with a certain delay. With each 'tick' you can then simply set the next image.
If you're after something a little more fancy, it may be worth looking at implementing an ImageSwitcher, which provides the ability to also show thumbs of upcoming/previous images. Code examples are wide spread, e.g. here (scroll down a bit).

Android image capturing and scaling

I am using the Camera activity to capture the JPEG image. After image is saved and the controll is returned back to my application activity I would like to to determine the captured JPEG image dimensions without loading the whole image into memory via Bitmap object - can it be easily done somehow?
Is there any class, which reads the JPEG header and give me such information? I would like to avoid OOM conditions - but might be it is not a problem to load the whole image into memory - is it?
After knowing the dimensions I would like to use BitmapFactory to scale the image.
Thanks a lot
Kind Regards,
STeN
Perhaps a work-around (see 2nd approach) by setting the quality?
bmp.compress(CompressFormat.JPEG, 75,
pfos);
You would have to do a trial run to see what size the quality gets you though...
*The first approach creates a log file to get the width and height but not sure if you wanted the extra step of looking at a log file.
You can use the ExifInterface class to read the image width and height.

Access to separate pixel of JPEG image in Android

In my android project I need to get access for each separate pixel of JPEG image. Image created by built-in photo application. I try to convert JPEG into Bitmap class instance, but OutOfMemoryException was thrown. After searching info about this problem I have found the following solution: resize image! But quality of image is important in my project, and i can't resize it. Is there any way to get each-pixel access?
if your image is too big and the quality is important i suppose the best way is to use or create your own class to cut the image in zone (eg : 50*50 px) , there is several jpeg info class in the internet to help you understand how work jpeg files.
Have you tried BufferedImage ? (it's not in the sdk but maybe usable)
The nature of jpeg makes it very hard to get the value of a single pixel. The main reason is that the data is not byte aligned, another is that everything is encoded in blocks that can be of sizes 8x16, 16x8 and 8x8. Also, you need to handle subsampling of chroma values.
If the image contains restart markers, maybe you can skip into the image so you don't have to decode the whole image before getting the pixel value.

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