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Images appear to not scale up with the size of the screen

I have created a centered layout. But it does not scale images up to device's dpi. How to make them bigger as device screen? Also how to scale them even in editor? Cause I can't. They are always this size.
Here is an example of ImageButton code:
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:srcCompat="#drawable/broadcasts"
android:background="?android:selectableItemBackground"
android:onClick="onWipButton_Click"
android:layout_marginRight="30dp"
android:layout_marginEnd="30dp"
android:id="#+id/imageButton2"
android:adjustViewBounds="true"
android:cropToPadding="false"
android:scaleType="fitXY"
android:layout_above="#+id/textView5"
android:layout_toLeftOf="#+id/textView5"
android:layout_toStartOf="#+id/textView5" />
Folder structure with all dpi.
On device with high dpi.
Design mode in studio.

I'm assuming you have actually do have assets of different sizes in those resource folders at zoom levels of 1x, 1.5x, 2x, 3x, 4x for m, h, xh, xxh, xxxh.
Then understand that devices are not fixed width either physically or in terms of dps. So while it may be correctly picking the correct resource for the resolution of the screen, that does not mean it will take up the same % of available width on every device. It should just be roughly the same physical size if measure with a ruler (roughly the same mind you).
In the designer, pick a screen with the same width and DPI. You should see the issue at design time.
If you want larger images, providing larger assets would be the simplest solution, and won't make blurry scaled images.
Then if you want the larger images only for larger screens, you could provide the larger assets in a drawable folder for large screens:
res/drawable-mdpi/
res/drawable-sw600dp-mdpi/
res/drawable-hdpi/
res/drawable-sw600dp-hdpi/
etc.
sw600dp is a "smallest width" qualifier, meaning it applies when the device has at least 600dp width available to it. This is a commonly used number to distinguish devices, it's what used to be known as a large screen. If you want to support different assets for 10" tablets, you might also use sw720.
Please see here for more info on the screen size resource folder qualifiers: https://developer.android.com/guide/practices/screens_support.html#NewQualifiers

Drawable and Android screen pixel density for fixed-size image

I'm going through a problem in an application here my related to this issue. See if you can help me:
In my case I have a ImageView showing a ruler, and then I need to show this rule in real size, where it does not need to grow or shrink as the screen size or density. Using as a basis my Moto G3, it works perfectly, but when testo other devices, it loses the actual size of a ruler because the image tries to fit the screen size.
The image of the ruler is in PNG and measures 3600px x 155px and has measured up to 30cm, it is within a LinearLayout orizontal. In my Moto G3 visible area it is in 10cm, a larger screen for example it should show a larger area of ​​the ruler (11 to 15cm for example), but it contunua only 10cm in the visual field of the screen, showing that it grows and shrinks as the display settings and density of the device.
Before I had a picture of RAGUA for each resource (xxhdpi, xhdpi, etc), so I decided to migrate it to the assets folder of Android, but still with the same problem.
Do you have a light on how to fix it?
Follows the code:
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/rulerPolegada"
android:layout_width="1780dp"
android:layout_height="103dp"
android:layout_marginTop="-10dp"
android:layout_marginLeft="#dimen/left_ruler"
/>
</RelativeLayout>
</HorizontalScrollView>
</LinearLayout>
And as I said, after I image for assets, I started to set it in java:
rulerPolegada = (ImageView) view.findViewById(R.id.rulerPolegada);
rulerPolegada.setImageDrawable(Controller.getImageAssets(getActivity(), "ruler_polegada.png"));

Due to Understanding Density Independence In Android, you can calculate those values as follows
Here is how you can calculate for your device (Moto G3)
30cm = 11.811 in
Moto G3 screen density bucket is xhdpi - 320dpi
320px ~= 1 in
320px * 11.811in ~= 3780px
With this steps you can calculate how big your image should be.
Now, instead of providing different ruler's images for different screen densities, place your high quality image in drawable-anydpi folder, because A drawable in res/drawable-anydpi/ also is valid for any screen density. However, in this case, the -anydpi variant trumps any density-specific variant. due to '-nodpi, -anydpi, and WTF?' article from The CommonsBlog
Unfortunatelly, you can't used calculated values in layout xml file directly - ImageView size needs to be changed dynamically in Java code.
Above solution should give you decent accurancy (it can be diffent by 10%), but you can use DensityMetrics together with default display to get actual horizontal and vertical density, which will help you calculate image pixel size more precisely.
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
// these will return the actual dpi horizontally and vertically
float xDpi = dm.xdpi;
float yDpi = dm.ydpi;
Edit
Calculation for 480dp:
30cm = 11.811 in
density bucket xxhdpi - 480dp
480px ~= 1in
480px * 11.811in ~= 5669px

I'm not sure if you get your answers correct because it appears that previous answers were not satisfied. I had once the same problem - I need this ImageView to have the same size on a plethora of devices without scaling. I solved my problem by providing defined value in dp for layout_width and layout_height

You should read this guide for run in multiscreen

Android screen size resolution

My app works perfectly in resolution 480x800. If I keep the 480x800 resolution but change the screen size to for example 2.7 inches, 3.7 inches or 5.4 inches it still is perfect. But when I change the resolution to for example 640x1066 all the ImageButtons is too small and in the wrong place in all screen sizes... I have created ImageButtons in all four folders(drawable-l, m, h, xh) but still the buttons is not in the correct size..
<ImageButton
android:id="#+id/ib1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="6dp"
android:layout_marginTop="433dp"
android:background="#drawable/imagebutton1" />
<ImageButton
android:id="#+id/ib2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="188dp"
android:layout_marginTop="436dp"
android:background="#drawable/imagebutton2" />
NOTE: My problem is not when I change screen size, but when I change screen resolution.

I would really like to see some code.
If you use RelativeLayout with attributes like android:layout_width and android:layout_height and specify values in dp (density pixels) e.g. android:layout_height="40dp" it should work just fine.
Please try to share some code with us.

Make sure that your assets that you have in your ldpi, mdpi, hdpi and xhdpi folders are scaled correctly to accommodate the diff. resolutions. I accidentally scaled some assets incorrectly, and although they were in the correct folders..gave me some bad results
http://developer.android.com/guide/practices/screens_support.html

Android screen size and resolution [duplicate]

My app works perfectly in resolution 480x800. If I keep the 480x800 resolution but change the screen size to for example 2.7 inches, 3.7 inches or 5.4 inches it still is perfect. But when I change the resolution to for example 640x1066 all the ImageButtons is too small and in the wrong place in all screen sizes... I have created ImageButtons in all four folders(drawable-l, m, h, xh) but still the buttons is not in the correct size..
<ImageButton
android:id="#+id/ib1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="6dp"
android:layout_marginTop="433dp"
android:background="#drawable/imagebutton1" />
<ImageButton
android:id="#+id/ib2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="188dp"
android:layout_marginTop="436dp"
android:background="#drawable/imagebutton2" />
NOTE: My problem is not when I change screen size, but when I change screen resolution.

I would really like to see some code.
If you use RelativeLayout with attributes like android:layout_width and android:layout_height and specify values in dp (density pixels) e.g. android:layout_height="40dp" it should work just fine.
Please try to share some code with us.

Make sure that your assets that you have in your ldpi, mdpi, hdpi and xhdpi folders are scaled correctly to accommodate the diff. resolutions. I accidentally scaled some assets incorrectly, and although they were in the correct folders..gave me some bad results
http://developer.android.com/guide/practices/screens_support.html

Why is wrap_content bigger than real pixel size?

I am trying to understand something. A weird thing that I see is that when I put wrap_content in the width and hight, the image is bigger than the the real px (pixel) size of the image which is inserted. Why is that so?
My code with wrap_content:
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="false"
android:src="#drawable/header" />
and thats my code with exact pixel size of the image:
<ImageView
android:id="#+id/imageView1"
android:layout_width="378px"
android:layout_height="155px"
android:adjustViewBounds="false"
android:src="#drawable/header" />
As you can see, thats the exact pixel size:
Why is that? I thought that wrap_content should wrap the view to the content size so why is it bigger on screen?

If you really need to use the image's pixels as-is, and use the screen actual pixels do the following:
1) Create a res/drawable-nodpi and move your fixed-pixel non-scaling images in there.
2) You then can use wrap_content as layout_width and layout_height, and image pixels will match the device pixels with no upscaling because of dpi.
From http://developer.android.com/guide/practices/screens_support.html, the definition of nodpi :
Resources for all densities. These are density-independent resources. The system does not scale resources tagged with this qualifier, regardless of the current screen's density.

A very nice explaintaion for supporting the multiple screens is given at
http://developer.android.com/guide/practices/screens_support.html.
you need to put images in respective folders after scaling.
e.g. if you want 100*100 image then place
75*75 in drawable-ldpi for Low density devices
100*100 in drawable-mdpi for Medium density devices
150*150 in drawable-hdpi for High density devices
200*200 in drawable-xhdpi for Extra High density devices

wrap_content means that you want the image as it as its original size is. i.e if the size of the image is 200*200 then it will show 200*200 and if the image size is 400*400 it will show of the size 400*400.
So the reason you are getting a larger image then what you actually get when you hard code it with real pixels is because of the LARGE SIZE of the image. i.e image is actually large.

From my experience I can say that wrap_content always utilize maximum available size possible. So sometimes it stretch the image & sometimes reduce the size of the image. To use exact image use android:scaleType="fitXY"
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="false"
android:scaleType="fitXY"
android:src="#drawable/header" />
Update after 1st 2 comments:
as per android docs :
You can specify width and height with exact measurements, though you probably won't want to do this often. More often, you will use one of these constants to set the width or height:
wrap_content tells your view to size itself to the dimensions required by its content
fill_parent (renamed match_parent in API Level 8) tells your view to become as big as its parent view group will allow.
In general, specifying a layout width and height using absolute units such as pixels is not recommended. Instead, using relative measurements such as density-independent pixel units (dp), wrap_content, or fill_parent, is a better approach, because it helps ensure that your application will display properly across a variety of device screen sizes. The accepted measurement types are defined in the Available Resources document.
I found the term size itself is important, it autometically resizes the images. thats why I told that from my experience I found sometimes it stretch the image & sometimes reduce the size of the image

You need to see where you put the image. If its in hdpi it will look bigger on screen then if its in hdpi when ising wrap_content. so, in order for it to be the exact size, put it in right library.