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Why are pictures always rectangular?

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  • User profile image
    Loadsgood

    I find it wierd that picture are always rectangular... Always. I know I can make an image look a different shape by making it have a transparent background, or colouring its background the same colour as the web page I would be using it on. But I have yet to see a picture-editing program that allows me to change the shape, of the box that the blank picture is in.
    Or when I change the resolution of one side of the picture, it changes the other side as well, what the hell?

    Who decided that those are the rules? That all pictures are square unless a transparent background is used and that when you change the resolution of one side of the rectangular picture, it changes the size of the other side as well.



    Why are we restricted?
    Loadsgood.

  • User profile image
    Detroit Muscle

    Historically, digital images have been stored as 2 dimesional arrays of integers.

  • User profile image
    Heywood_J

    Look at the standard resolutions of computer monitors:

    640x480
    800x600
    1024x768
    etc.

    None of them are square.  They are all rectangular, so, graphics programs are designed to fit the monitor.

  • User profile image
    jamie

  • User profile image
    brian.​shapiro

    well if you wanted an oval drawing space; either the oval would be jagged, or it would need alpha blending to look smooth. this is because the screen uses square pixels. a jagged oval is not worth much, and if you want alpha blending it needs to be done within a rectangle anyway, in order to shape the outer rim of the oval. if display technology in the future works in a way in which square pixels aren't used then maybe you can talk about different shaped drawing spaces but not before then.

    btw if you look at art before computers a lot of canvases have been oval, but still they would have been cut from a rectangle shape. because its easier and more efficient to produce canvas in rectangle shapes and allows the buyer to cut it anyway he wants, while with an oval he would be limited.

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    Deactivated User

    Comment removed at user's request.

  • User profile image
    Maurits

    Close... actually the ease of recognizing horizontal and vertical lines applies much more to computers than it does to humans.

    In particular, given:

    Window A of width wa and height ha at (xa, ya)
    Window B of width wb and height hb at (xb, yb)

    it is easy to calculate the region of overlap - which is also a rectangle!

    This isn't the case with any other shape.

    A nice "why are manhole covers round" question Smiley

  • User profile image
    Loadsgood

    Seems technology isn't up to the height of my needs yet again Wink Maybe one day 3D monitors or holograms/3D projections etc. will be created and my dream for the creation of non-rectangular pictures will come true Smiley Or I could just wack Paint.NET's source code into a triangular blank picture creator or a pentagon or hexagon etc. Maybe even go one step further and make circular shapes or enable the user to reshape the rectangular blank picture via clicking and dragging tiny boxes attached to the lines.... Hmmmm.



    A square is a type of rectangle. By definition a rectangle is a rectangle if it has two pairs of sides that are the same length as the opposite side, a square qualifies.
    Loadsgood.

  • User profile image
    NeoTOM

    Loadsgood wrote:
    Seems technology isn't up to the height of my needs yet again Maybe one day 3D monitors or holograms/3D projections etc. will be created and my dream for the creation of non-rectangular pictures will come true Or I could just wack Paint.NET's source code into a triangular blank picture creator or a pentagon or hexagon etc. Maybe even go one step further and make circular shapes or enable the user to reshape the rectangular blank picture via clicking and dragging tiny boxes attached to the lines.... Hmmmm.



    A square is a type of rectangle. By definition a rectangle is a rectangle if it has two pairs of sides that are the same length as the opposite side, a square qualifies.
    Loadsgood.


    I once seriously tried hex pixel emulation in Paint. Believe me when I say it's not worth it.

  • User profile image
    Maurits

    Loadsgood wrote:
    A square is a type of rectangle. By definition a rectangle is a rectangle if it has two pairs of sides that are the same length as the opposite side, a square qualifies.


    Almost Smiley that's a parallelogram.

    A rectangle is a parallelogram whose angles are all equal.

    A rhombus (AKA diamond) is a parallelogram whose sides are all equal.

    A square is a rectangle that is also a rhombus.

  • User profile image
    W3bbo

    Maurits wrote:
    Almost that's a parallelogram.

    A rectangle is a parallelogram whose angles are all equal.

    A rhombus (AKA diamond) is a parallelogram whose sides are all equal.

    A square is a rectangle that is also a rhombus.


    Wouldn't "quadrilateral" be more appropriate?

    Maurits wrote:
    A nice "why are manhole covers round" question


    Where I live, manhole covers are rectangles.

  • User profile image
    WiredCoder

    W3bbo wrote:

    Maurits wrote:A nice "why are manhole covers round" question
    Where I live, manhole covers are rectangles.



    Look out belowwww.... thunk

  • User profile image
    billh

    Loadsgood wrote:
    I find it wierd that picture are always rectangular... Always. I know I can make an image look a different shape by making it have a transparent background, or colouring its background the same colour as the web page I would be using it on. But I have yet to see a picture-editing program that allows me to change the shape, of the box that the blank picture is in.
    Or when I change the resolution of one side of the picture, it changes the other side as well, what the hell?

    Who decided that those are the rules? That all pictures are square unless a transparent background is used and that when you change the resolution of one side of the rectangular picture, it changes the size of the other side as well.


    You would probably have to start with your own graphics file format first, then work your way up.  I mean down at the binary level, too.  Design/build your own header information, etc.  Something in the format would also have to designate what type of shape it is...would you have a pre-defined list of shapes to choose from (square, circle, ellipse, hexagon)?  Or would you allow the user to rely on a formula for the outer edges?  Then, you would have decide how the pixels are going to be ordered in memory.  Will you paint the picture in typical fashion such as left to right, top to bottom?  Or, in the case of a circle, would you start from the innermost center pixel and spiral your way out (yikes)? 

    Then, building a program that handles that format would be probably be easier.  Transformations would be probably be easier, too (scaling, skewing). Also, would it be "vectors" or pixels?

  • User profile image
    amotif

    Loadsgood wrote:
    I find it wierd that picture are always rectangular...


    Most "pictures" are bitmaps, at least in the context in which I think we're discussing this. Something to ponder: If you were inventing a bitmap format would it, in the end, be a rectangular format? Would that make your format easy to understand & use?  How would bitmaps in a non-rectangular format be easy or difficult to use? To measure? To tile? To rotate? To otherwise manipulate?

  • User profile image
    Minh

    Here's another puzzling question. If with the honey comb shape, we can have the most inner space with the least material, why do we continue to build retangular houses?

  • User profile image
    Steve411

    Loadsgood -

    Because it is. Smiley

    Steve.

  • User profile image
    andokai

    I would imagine it is because a rectangle has the simplest bounding area, ie. 2 points. Plus it's simpler to store pixel values in a two dimensional array.

  • User profile image
    Maurits

    Minh wrote:
    with the honey comb shape, we can have the most inner space with the least material


    O

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