Post Values from Uneditable input fields

Sometimes you want to set the data of an input field through JQuery and at the same time you need that field to be uneditable, then the workaround is to add the attribute 'readonly' to that field. Being 'readonly' makes the field uneditable and the form will submit the value as well whereas the attribute 'disabled' makes the field uneditable but the form will not submit the value.

Example:

<input name="un_editable_field" type="text" readonly />

Now you can get the values normally in the action file

$value = $_POST['un_editable_field'];

Create clean encoded URL variables

If you try to use strings with characters '@,=,+....' etc in URLs in CodeIgniter, it will throw 'URL Disallowed character' error. So you can't pass an email address which is like 'name@email.com' in the CodeIgniter URL.
So the workaround is to encode the desired string, in this case 'name@email.com' pass it to the URL and decode it wherever necessary.

$string = "name@email.com";
$enc = rtrim(base64_encode($string),'=');    //encoded string which can be used in URL

$dec = base64_decode($enc); //decoded string

The function base64_encode($string) encodes the string into 'bmFtZUBlbWFpbC5jb20=' which still contains an '=' character. So use the function rtrim to get rid of that '='.

Green Bee-Eater

This is a small green bee-eater.
Captured while I took a walk around the paddy fields near home.

Camera: Canon EOS 60D
Lens: Tamron 70-300 mm
Aperture: f/5.6
Shutter speed: 1/1250 sec
ISO: 800

Simple HDR image of an evening scene using Photoshop

Today when I took an evening walk an idea came to my mind to make an HDR image of the evening scene. HDR stands for High Dynamic Range. Dynamic range is the range of brightness from pure black to the fullest brightness. Our eyes can't recognize dynamic range beyond a level. Our camera too is not capable of capturing the whole dynamic range of brightness! Its a broad and interesting topic, if you want to read about it here is the wikipedia link about hdr
If you see a sunset it's awesome, right? But what if you want it to get captured with your camera? The truth is that you cannot capture every detail you see at the moment. If you capture it, chances are that either the sky loses its detail or the ground loses detail. You can't get both(sky and ground) details in a single shot! But there's a workaround. We can use two images, one with a low exposure and another with a normal exposure and blend the two images in Photoshop.
Okay so here is my scenario. It was about 6 pm in the evening when I took the images. The sky looks awesome and I needed the image to look like the one I was seeing through my eyes!
So here are my steps. First I positioned the mobile camera towards the scene as straight as possible. Then slowly tilt the camera upwards in a rotating motion such that the screen now shows sky in full details and the ground become dark. Take the shot. It is also called silhouette image.

Image with details of the sky (silhoutte)

After clicking the first image, slowly tilt the camera downwards such that the screen shows the ground in full details. This time the sky become blown out in the screen. Take the shot.

Image with details of the ground.

Now we have two images, the first one having details of the sky and the second one having details of the ground. Here is the result after blending the images.

Final image

First fire up photoshop and open the two images in it. Then go to File>Automate>Photomerge

File>Automate>Photomerge

Now the Photomerge window will open. Click on Add Open Files and it shows the two files you opened. In the layout section select Auto. At the bottom of the window check Blend Images Together and leave the other two unchecked and hit OK button.

Photomerge window.

Now photoshop blends the two images for us and in my case it generated this.

Photoshop generates the blended image.

Using Crop tool crop the image for the relevant area.

Crop out the unnecessary areas

Now you notice that the middle area is dark. Photoshop's algorithm made the under exposed image visible at the middle area and the second image's middle area is masked out. Next step is to extract the second image's masked out area. Go to Layers panel. If Layers panel is not there, click Window>Layers 

Select the layer mask of the normally exposed image, that is the top layer.

There are two layers, at the bottom it is the under exposed image and at the top it is the normal exposed image. Their corresponding masks are shown alongside each layer. The white area in the mask makes the corresponding area of the layer visible and the dark area makes the corresponding area hidden.
Since we need the normally exposed image's middle portion, we need to make it visible. So select the second layer's mask. Its important to select the layer's mask and not the layer otherwise we will be drawing in the original image! The layer mask gets a border once you select the mask. Watch for that.

Select the layer mask of the top layer

Now use a brush of convenient size with white color, in my case I used 343 sized brush. Set the opacity to 15% and slowly paint along the middle portions(the areas you want the details)

Using a brush with white as foreground color paint in the mask to remove the dark areas

Finish painting the middle area until it blends with the rest of the image.

Paint in the mask until all the details are shown

Now our blending part is over and now add some contrast and vibrance to the image to get it stand out.

Add a Contrast adjustment layer and Vibrance adjustment layer and move the sliders until you are satisfied with the result

The final image. Remember the images are shot at 6 pm

Okay, so that's a simple procedure to create an HDR image. We can create very dramatic photos using hdr techniques. There are other methods like taking three different images with each one varying in exposure value by one or two steps and using the Merge to Hdr Pro feature of Photoshop. I will a make a tutorial on that later.
Hope you enjoyed it.