[racket] Artefact when cropping and scaling an image

Thanks for checking it out -- sounds like it may be fixed / one for the
test suite.

Will 5.3.7 be coming soon?

Dan


On Tue, Nov 19, 2013 at 11:40 AM, Robby Findler <robby at eecs.northwestern.edu
> wrote:

> Ah. I'm not sure which change affected this, but in the git version from
> last night I see a solid red square (and I do see the same thing as you in
> 5.3.6).
>
> Robby
>
>
> On Mon, Nov 18, 2013 at 6:36 PM, Daniel Prager <daniel.a.prager at gmail.com>wrote:
>
>> Image attached.
>>
>> System: Mac, OS X 10.8.5, Racket 5.3.6.
>>
>> Dan
>>
>>
>> On Tue, Nov 19, 2013 at 11:28 AM, Robby Findler <
>> robby at eecs.northwestern.edu> wrote:
>>
>>> I'm not seeing what you're seeing, I think. Can you send a screenshot
>>> (or a pointer to it)?
>>>
>>> Robby
>>>
>>>
>>> On Mon, Nov 18, 2013 at 5:59 PM, Daniel Prager <
>>> daniel.a.prager at gmail.com> wrote:
>>>
>>>> Why does the following code generate visual artefacts along the right
>>>> and bottom
>>>> edges of the image?  How do I eliminate it?
>>>>
>>>> #lang racket
>>>> (require 2htdp/image)
>>>>
>>>> (define (crop-to-aspect-ratio im final-width final-height)
>>>>   (let* ([W (image-width im)]
>>>>          [H (image-height im)]
>>>>          [wh-ratio (/ final-width final-height)]
>>>>          [w (* wh-ratio H)]
>>>>          [h (/ W wh-ratio)]
>>>>          [image (if (<= W w)
>>>>                     (crop 0 (/ (- H h) 2) W h im)
>>>>                     (crop (/ (- W w) 2) 0 w H im))])
>>>>     (freeze (scale (/ final-width (image-width image))
>>>>                    image))))
>>>>
>>>> (scale 5
>>>>        (crop-to-aspect-ratio
>>>>         (freeze (rectangle 259 356 'solid 'red))
>>>>         40 56))
>>>>
>>>>
>>>> Note that the two freeze instructions are essential -- the one in the
>>>> crop routine
>>>>  forces pixelation, which I want -- and the one in the calling code
>>>> simulates starting with a bitmap.
>>>>
>>>> Thanks
>>>>
>>>> Dan
>>>>
>>>> ____________________
>>>>   Racket Users list:
>>>>   http://lists.racket-lang.org/users
>>>>
>>>>
>>>
>>
>>
>> --
>> *Daniel Prager*
>> Agile/Lean Coaching, Software Development and Leadership
>> Twitter: @agilejitsu <https://twitter.com/agilejitsu>
>> Blog: agile-jitsu.blogspot.com
>>
>
>


-- 
*Daniel Prager*
Agile/Lean Coaching, Software Development and Leadership
Twitter: @agilejitsu <https://twitter.com/agilejitsu>
Blog: agile-jitsu.blogspot.com
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