Image rescaling for IMAGE()

[Joe7M]

Hi Chris,

I have different Android devices with different screen sizes and pixels. I was missing an easy way to rescale an image to adapt for the screen size and pixel size.

I added an optional parameter to the IMAGE() function to scale the image. The algorithm is almost "nearest neighbor". Instead of round() I use floor(). This is much faster and was easier to implement. Getting the scaling with all possible cases of IMAGE() working, was not as easy as I thought in the beginning. That is the reason, why the same lines of code are repeated several times in the source file.

Syntax is as following:

I1 = image("test.png")             ' without scaling
I1.show(1,1)
I2 = image("test.png", 0.5)     ' downscaling by factor 2
I2.show(65,1)
I3 = image("test.png", 2)        ' upscaling by factor 2
I3.show(97,1)

I4 = Image(I1)
I4.show(1,128)
I5 = Image(I1, 0.5)
I5.show(65,128)
I6 = Image(I1, 2)
I6.show(97,128)

I7 = Image(1,1,64,64)
I7.show(1,256)
I8 = Image(1,1,64,64,0.5)
I8.show(65,256)
I9 = Image(1,1,64,64,2)
I9.show(97,256)

a << "64 64 3 1" 
a << "a c #FF0000"
a << "b c NONE"
a << "c c #0000FF"
For ii = 1 To 64
  a << String(20, "a") + String(24, "b") + String(20, "c")
Next
I10 = Image(a)
I10.show(1,256+128)
I11 = Image(a,0.5)
I11.show(65,256+128)
I12 = Image(a,2)
I12.show(97,256+128)

dim B
I1.save(B)
I13 = Image(B)
I13.show(1,512)
I14 = Image(B,0.5)
I14.show(65,512)
I15 = Image(B,2)
I15.show(97,512)

Best regards, Joerg

[chrisws]

Could you please change all the occurrences "if(" to "if (" (ie add the space)
(same with for( later)

[Joe7M]

done.

[chrisws]

This sets up for SmallBASIC try/catch handling but isn't itself a throw like with java etc.
So you still need to avoid invoking the code below. So either use else { ... or return here.
In this case a simple return is the simplest solution.

[Joe7M]

Thanks, I didn't know that. I changed it.

[chrisws]

Thanks for this, looks useful.

Could you please also include an example?

[Joe7M]

I added examples to the source code. I hope that's what you want. Later I'll add a description to the our website. I can also create an example in smallbasic.samples.